AN ABSTRACT OF THE THESIS OF
CHARLES EDWARD TRAINER
(Name)
in
WILDLIFE MANAGEMENT
(Major)
for the
MASTER OF SCIENCE
(Degree)
presented on
ci
(Date)
Title: THE RELATIONSHIP OF PHYSICAL CONDITION AND
FERTILITY OF FEMALE ROOSEVELT ELK (CERVUS
CANADENSIS ROOSEVELTI) IN OREGON
Abstract approved:
Redacted for Privacy
Howard M. Wight
The ratio of calves to cows observed annually during winters of
1950-69 for Roosevelt elk in Western Oregon indicated that about ZO
percent fewer calves were seen than in similar inventories for Rocky
Mountain elk (Cervus canadensis nelsorli) in Northeast Oregon. To
determine if fertility was an important cause of the comparatively low
percentage of calves recorded for Roosevelt elk, factors affecting reproduction in the subspecies were investigated.
Examination of Z64 uteri of adult (two years and older)
Roosevelt elk collected on three study areas in Western Oregon during
the November-January periods,
1964-68
revealed that 50 percent were
pregnant. By contrast, a pregnancy rate of 88 percent was evident
for 90 adult Rocky Mountain elk harvested in Northeast Oregon between November and January,
1967-68
and
1968-69.
Comparison of
the average 50 percent rate of pregnancy apparent for adult Roosevelt
elk examined during 1964-68 with the mean calf: cow ratio of 41 per-
cent observed about 13 months later, indicates that the proportion of
calves enumerated was largely determined by fertility rather than
postnatal survival. Different percentages of pregnant cows were evident among various age groups of Roosevelt elk; yearlings (12 per-
cent), two and three year olds (32 percent), four to ten year olds (59
percent) and all of the eight cows examined, estimated to be older than
ten years, were nongravid.
None of 14 nonpregnant yearling Roosevelt elk sampled had
ovulated, and the evidence of infertility identified in a sample of 79
nongravid adults intensively studied was apparent as embryonic
mortality (minimum of two percent) and anovulation (23 to 64 percent).
Tests for diseases harmful to reproduction indicated that pathological
factors were not affecting fertility. An indicated decline in the ratio
of bulls in Roosevelt elk herds (a result of increased harvests) coupled
with no apparent decrease in calf: cow ratios suggested that the relatively low fertility rate in the subspecies originated with the female.
Measurements of kidney fat depots indicated significant differences in physical condition between pregnant and nonpregnant cows
that were not revealed by adrenal weight indices. Among cows 3-10
years old, there was evidence of significantly larger kidney fat deposits
in gravid than in nongravid females. Lactating cows (3-10 years old)
were indicated to have significantly smaller depots of kidney fat
and a lower pregnancy rate (51 percent pregnant) than nonlactating
cows (84 percent pregnant). Earlier dates of breeding were generally
apparent for adult cows in the best physical condition.
The relationship between fat stores and fertility evident for fe-
male Roosevelt elk indicates that environmental factors, probably re1.ated to nutrition, were the underlying cause of the low reproductive
rates observed in the subspecies. The stress of lactation was identified as the main physiological process affecting energy reserves of the
cow to the detriment of fertility.
Data were not available to determine if reproduction was limited
because of qualitative or quantitative deficiencies in forage. Research
concerning the effect of various population densities of Roosevelt elk
upon fertility is suggested to determine whether or not the present
level of reproduction represents the maximum net productivity possible under prevailing environmental conditions.
The Relationship of Physical Condition and Fertility
of Female Roosevelt Elk (Cervus canadensis
roosevelti) in Oregon
by
Charles Edward Trainer
A THESIS
submitted to
Oregon State University
in partial fulfillment of
the requirements for the
degree of
Master of Science
June 1971
APPROVED:
Redacted for Privacy
Professor of Wildlife Ecology
in charge of major
Redacted for Privacy
Head of Department of Fisheries and Wildlife
Redacted for Privacy
Dean of Graduate School
Date thesis is presented
Typed by Donna L. Olson for
Charles Edward Trainer
ACKNOWLEDGEMENTS
My sincere appreciation is expressed to Mr. Howard Wight,
Professor of Wildlife Ecology, Department of Fisheries and Wildlife,
for his careful guidance during the study. I am also grateful to the
Oregon State Game Commission for supporting the investigation under
Pittman-Robertson Project W-59-R.
This study would not have been possible without the cooperation
of many individuals. I wish particularly to thank Mr. James Harper
and Mr. William Lightfoot for many long and often difficult days spent
in the planning and supervision of special hunting seasons involved with
collection of elk. Special recognition is due to Messrs. Lyle Carver,
Kenneth Cochrun, William Hall, Francis Ives, Frank LeMay, Robert
Mace, John Rayner, Robert Stein, Harold Sturgis and Donald Wilt for
their assistance with the intensive collection of specimens on the
Millicoma area. I also wish to thank other Game Commission person-
nel, members of the State Police and hunters who submitted much
material for examination and aided the study in other ways.
Appreciation is extended to Mr. Warren Aney and Dr. W. Scott
Overton for their aid with statistical analyses, and to Dr. Dean Smith
for conducting tests for pathogens. I am grateful to Dr Paul Vohs
for his thoughtful criticism of the manuscript.
Dr. Kenneth Greer, Montana State Department of Fish and
Game, Dr. B. W. O'Gara, U. S. Fish and Wildlife Service and Dr.
Philip Wright, University of Montana, provided many helpful sugges-
tions concerning the laboratory work. Their assistance is gratefully
appreciated.
Above all I wish to acknowledge my wife, Clara, and daughters
Audrey and Kimberly for their willing acceptance of the many hours
which I spent apart from the family to complete the research and
thesis.
TABLE OF CONTENTS
Chapter
I.
Page
INTRODUCTION
1
II. METHODS
4
Collection of Specimens
Laboratory Methods
Terminology
III. RESULTS
4
6
9
11
Breeding Season
Breeding Seasons of 1967 and 1968
Physical Condition and Period of Breeding
Fertility
Pregnancy Rates
Incidences of Twinning and Multiple Ovulation
Evidence of Infertility
Infertility inYearlings
Infertility in Adults
Anovulation
Embryonic Mortality
Infertility in Rocky Mountain Elk
Factors Influencing Fertility
Pathology
Diseases Associated with Reproduction
Abnormalities in Uteri and Ovaries
Male Coverage
Physical Condition
Indices of Physical Condition
Indices of Kidney and Marrow Fat
Indices of Adrenal Weight
IV. DISCUSSION
V. CONCLUSIONS
11
11
15
20
20
26
27
27
28
28
30
32
34
34
34
35
36
37
37
40
48
53
62
LITERATURE CITED
64
APPENDICES
68
LIST OF FIGURES
Figure
1.
2.
Page
Present distribution of elk in Oregon and study
areas where Roosevelt elk were collected, 196468 reproductive seasons.
Relationship of kidney fat indices and dates of
breeding for 25 female Roosevelt elk, 3-10 years
old, collected in Western Oregon, November 2-17,
1968.
3.
4.
5.
Relationship of kidney fat indices and dates of
breeding for 20 female Roosevelt elk, 3-10 years
old, collected in Western Oregon, January 6-28,
5
17
1968.
18
Kidney fat indices plotted against percentage of
fat (wet basis) in metatarsal marrow for 54 female
Roosevelt elk, three years and older, collected in
Western Oregon, November 2-December 15, 1968.
41
Kidney fat indices plotted against percentage of fat
(wet basis) in metatarsal marrow for 41 female
Roosevelt elk, three years and older, collected in
Western Oregon, January 3-28, 1968.
42
LIST OF TABLES
Table
1.
2.
3.
4.
5.
6.
7,
Page
Dates of breeding calculated for adult female
Roosevelt elk collected in Western Oregon,
1967 and 1968 reproductive seasons (dates of
collection in parenthesis).
12
Dates of breeding calculated for adult female
Rocky Mountain elk collected in Northeast Oregon,
1967 and 1968 reproductive seasons (dates of
collection in parenthesis).
13
Pregnancy rates of Roosevelt elk collected in
Western Oregon, 1964-68 reproductive seasons
(dates of collection in parenthesis).
21
Comparison of age specific pregnancy rates
among samples of Roosevelt and Rocky Mountain
elk (outside collection dates in parenthesis--all
years listed as reproductive seasons),
25
Infertility identified in nongravid adult Roosevelt
elk collected in Western Oregon, 1965, 1967 and
1968 reproductive seasons.
29
Description of occurrences and suspected occurrences of embryonic mortality for Roosevelt elk
collected in Western Oregon, 1965, 1967 and 1968
reproductive seasons.
31
Infertility identified in nongravid Rocky Mountain
elk collected in Northeast Oregon, 1967 and 1968
reproductive seasons.
33
8.
Ratios of bulls and calves per 100 cows recorded
annually for Roosevelt elk in Western Oregon between December and mid-February, 1950-70,
9.
Indices of kidney fat for yearling and two year old
female Roosevelt elk collected in Western Oregon,
1968 reproductive season; all specimens nonlactating.
44
Table
10.
11.
1Z.
13.
Page
Relationship of pregnancy rates and status of
lactation for Roosevelt elk, 3-10 years old,
collected in Western Oregon, 1967 and 1968
reproductive seasons.
46
Relationship of pregnancy rates and status of
lactation for Rocky Mountain elk, 3-10 years
old, collected in Northeast Oregon, 1967 and 1968
reproductive seasons.
47
Correlation coefficients (r) computed from correlation of three indices of adrenal weight with
variables listed for female Roosevelt elk, 3-10
years old, collected on Millicoma area, 1967 and
1968 reproductive seasons,
50
Coefficients of determination (R2) and F values
resulting from stepwise multiple linear regression
analysis of adrenal weight: hog-dressed body weight
ratio Y on variables listed for female Roosevelt
elk, 3-10 years old, collected on Millicoma area,
1967 and 1968 reproductive seasons.
51
LIST OF APPENDIX TABLES
Appendix 1
Table
A.
B.
C.
E.
F.
G.
1-1.
I.
J.
Page
Ovarian and uterine data--pregnant
Roosevelt elk collected on Millicoma
area, November 20 and 21, 1965.
Ovarian and uterine data- -pregnant
Roosevelt elk collected on Millicoma
69
area, January 6-28, 1968.
70
Ovarian and uterine data--pregnant
Roosevelt elk collected on Millicoma
area, November 2 - December 14, 1968.
71
Ovarian and uterine data--pregnant
Roosevelt elk collected on North Coast
area, November 11-18, 1967.
72
Ovarian and uterine data--pregnant
Roosevelt elk collected on North Coast
area, November 16 and 17, 1968 and
February 15, 1969.
73
Ovarian and uterine data--pregnant
Roosevelt elk collected on Loon Lake
area, November 17 - December 15, 1968.
74
Ovarian and uterine data- -nonpregnant
Roosevelt elk collected on Millicoma area,
November 20 and 21, 1965.
75
Ovarian and uterine data--nonpregnant
Roosevelt elk collected on Millicoma area,
January 3 February 25, 1968.
76
Ovarian and uterine data--nonpregnant
Roosevelt elk collected on Millicoma area,
November 2 - December 14, 1968.
77
Ovarian and uterine data--nonpregnant
Roosevelt elk collected on North Coast area,
November 11 - December 6, 1967.
78
Appendix 1
Table
K.
L.
Page
Ovarian and uterine data- -nonpregnant
Roosevelt elk collected on North Coast area,
November 16 and 17, 1968,
79
Ovarian and uterine data- -nonpregnant
Roosevelt elk collected on Loon Lake area,
December 7-15, 1968.
80
Ovarian and uterine data- -pregnant Rocky
Mountain elk collected in Northeast Oregon,
November 11, 1967 - January ZO, 1968.
8Z
Ovarian and uterine data--pregnant Rocky
Mountain elk collected in Northeast Oregon,
November 16, 1968 - January Z5, 1969.
83
Ovarian and uterine data- -nonpregnant Rocky
Mountain elk collected in Northeast Oregon,
November 11-19, 1967.
85
Ovarian and uterine data- -nonpregnant Rocky
Mountain elk collected in Northeast Oregon,
November 16 and 17, and December 22, 1968.
86
Sex of Roosevelt and Rocky Mountain elk
fetuses collected in Oregon, 1965, 1967 and
1968 reproductive seasons,
87
Data on physical condition for pregnant
Roosevelt elk collected on Millicoma area,
1967 reproductive season,
88
Data on physical condition for nonpregnant
Roosevelt elk collected on Millicoma area,
1967 reproductive season,
89
Appendix Z
Table
A.
B.
C.
D.
Appendix
Table
3.
4.
5.
Appendix
Table
6,
7.
Page
Data on physical condition for pregnant
Roosevelt elk collected in Western Oregon,
1968 reproductive season,
90
Data on physical condition for nonpregnant
Roosevelt elk collected in Western Oregon,
1968 reproductive season.
9Z
THE RELATIONSHIP OF PHYSICAL CONDITION AND
FERTILITY OF FEMALE ROOSEVELT ELK
(CERVUS CANADENSIS ROOSEVELTI)
IN OREGON
I.
INTRODUCTION
The purpose of this study was to relate physical condition and
other factors that influence reproduction to fertility rates observed
for female Roosevelt elk in Oregon. It is hoped that data presented
will increase understanding of factors affecting reproduction in
Roosevelt elk populations and thereby contribute to knowledge essen-
tial for management of the herds.
Two subspecies of elk occur in Oregon. Mace (1956) reports
that Roosevelt elk are distributed intermittently throughout the Coast
and Cascade Mountain ranges, whereas Rocky Mountain elk are found
in the northeast section of the state, principally in the Blue and
Wallowa mountains (Figure 1).
Schwartz and Mitchell (1945: 311) recorded an average of 61
calves per 100 cows for 419 Roosevelt elk cows and Z55 calves classified on the Olympic Peninsula, Washington in July and August of 193638
But ratios of calves to cows on Afognak Island, Alaska averaged
only 3Z: 100 during the summers of 1961 -63 (Batchelor, 1965: 14)
Calf: cow ratios obtained for Roosevelt elk in Oregon from December
a
to mid-February, 1950-69 revealed an average of 41 calves per 100
cows for 11,522 calves and 27,938 cows classified. Similar data for
Rocky Mountain elk, involving observations of 20, 013 calves and
39. 538 cows during the same period in Northeast Oregon averaged 51
calves per 100 cows or 20 percent more calves than for Roosevelt
elk.
The ratio of calves to cows indicated for Roosevelt elk suggested that many cows might not produce an offspring, or their young
died, or cows were more readily observable than calves. Interpreting
counts of calves, therefore, required knowledge of the proportion of
femaLes likely to be pregnant. To fill this need, uteri from Roosevelt
elk killed during 1964, 1965 and 1966 on the Millicoma Tree Farm in
Southwest Oregon were examined for evidence of pregnancy. Of 125
females (two years and older) examined, only 46 percent were gravid
(Harper, 1965:7; unpublished field notes, 1965; and 1967: 3). By
comparison, reproductive rates calculated from uterine analysis of
adult (two years and older) Rocky Mountain elk were much higher.
Kittams (1953: 183) reported a pregnancy rate of 85 percent for 1,053
adult cows killed in Yellowstone National Park between 1935 and 1951.
Greer (1966: 124) found that from 80 to 95 percent of the adult females
comprising samples collected annually in Yellowstone Park from 1961
to 1965 were gravid.
Consideration of the markedly different reproductive rates
3
observed for the two subspecies raised the question of why rates were
lower in Roosevelt elk. Consequently, my study was initiated in
Noember, 1967 to investigate certain factors affecting fertility in
Roosevelt elk; specifically to:
(1)
determine the fertility rate.
(2)
identify, insofar as possible, factors that inhibit fertility.
(3)
determj.ne the duration of the breeding season.
(4)
assess the physical condition of cows examined to relate
condition of the animal to fertility.
4
II. METHODS
Collection of Specimens
The present study is based on examination of 289 uteri of
Roosevelt elk killed in the Coast Range of Oregon from 1964 to 1968.
No specimens were obtained earlier than November or later than
February each year. James Harper analyzed uteri collected prior to
1967.
The specimens originated from three locations that I have desig-
nated as North Coast, Loon Lake, and Millicoma study areas (Figure
1). Although high densities of elk prevailed in the three localities,
most specimens (240) were from the Millicoma area- -a 110-square
mile portion of the Millicoma Tree Farm lying north and northeast of
Coos Ridge.
To compare with similar data on Roosevelt elk, biologists collected uteri from 105 Rocky Mountain elk harvested throughout Northeast Oregon during the November-January periods, 1967 and 1968,
Three methods were employed to gather materials for study.
Hunters participating in antlerless -only elk seasons were briefed about
the collecting program and asked to save reproductive tracts, udders,
and mandibles from cows they killed. Appropriate instructions, dia-
grams, and storage bags were supplied. The completeness of samples
received from hunters seemed related to the amount of time spent
5
//
7/
//
/
b/
/
-12)
/
/
0000000
000000 0
0 0 0
00
0
00
0
0 0
0 0
o0 0
o'00°0
0000
0 000000
0 0 0 0 0
00000
0
00
0
0
0
00
0/
0/
Legend
Roosevelt Elk Distribution
0 0 0
0
0000
---Study Areas:
= Rocky Mountain Elk Distribution
=
Study Area Boundary
1.= North Coast
3 = Millicoma
2 = Loon Lake
Figure 1. Present distribution of elk in Oregon (Mace, 1956) and study areas
where Roosevelt elk were collected, 1964-68 reproductive seasons.
instructing the individual.
Personnel concerned with enforcement duties also submitted
materials from cows killed illegally.
Supervised hunts were conducted during January, 1968 and
November, 1968 on the Millicoma area to provide Roosevelt elk for
intensive study. From six to ten hunters per day were scheduled
during each hunt. On the appointed days, biologists accompanied the
parties afield and obtained the following items from each elk killed:
whole and hog-dressed weights, the reproductive tract, mandible,
udder, kidney fat depots, adrenals, one metatarsal bone, and a sample
of blood. Both hunts proved successful from standpoints of data
col-
lected and satisfaction of hunters.
Uteri were preserved in AFA (Mossman's recipe--Guyer, 1953:
236) or by freezing. Other materials were kept cool or frozen until
examined.
Laboratory Methods
Study of reproductive tracts under laboratory conditions included
examination of the ovaries, uterine contents, cervix and vagina. Tis sues for histological study were sectioned at seven microns and stained
with Harris' hematoxylin and Putt's eosin,
Ovaries (fixed) were sliced along the longitudinal axis with a
razor blade into sections 1 to 2. mm thick, leaving the sections
7
attached to the mesovarium. The average diameter (measured at
right angles) of corpora lutea, corpora albicantia, and all follicles
larger than 2 mm was then tabulated.
All uteri were dissected and examined for evidence of pregnancy. Uteri showing an initial enlargement typical of early preg-
nancy, or with ovaries containing corpora lutea, were severed from
the tract at the mid-cervical region and trimmed of mesometrial
tissue. The uterine horns were then opened while submerged in tap
water, and a search was conducted for small, macroscopic embryonic
tissue. No attempt was made to recover ova or microscopic-sized
blastocysts. The cervical and vaginal mucosa were also examined
for abnormalities.
Embryos were removed from gravid uteri, scrutinized for external anomalies and the sex, body length, and weight recorded.
Following procedures outlined by Armstrong (1950: 652) and Morrison,
Trainer and Wright (1959: 29), I used two methods of measuring length
in embryos. These were:
Crown-rump length -- For specimens up to 64 mm, the distance
between the anterior-most to the posterior-most points of the
body was measured.
Forehead-rump length -- For specimens larger than 64 mm, the
embryo was placed on its side with its back against a straight
surface and care was taken to prevent the head from curling
tailward. The distance measured was from the anterior-most
point of the crown to the tuberosity of the ischium.
Dates of conception were calculated using a growth curve derived from Rocky Mountain elk embryos of known age (Morrison,
Trainer and Wright, 1959).
Ages of elk were estimated at the birthdate previous to date of
collection according to tooth replacement and wear patterns described
by Quimby and Gaab (1957).
With one modification, deposits of kidney fat were measured
using the kidney fat index (weight of fat surrounding the kidneys
divided by weight of the kidneys) described by Riney (1955: 433 and
434). Riney cut away and discarded fat anterior and posterior to the
kidney before weighing the remaining fat. To avoid variation in maintaming a 900 cutting plane when trimming fat from ends of the kidneys
(B. W. OGara, personal communication, 1967), calculation of the index in my study (based on both kidneys and expressed in percent) in-
cluded all fat attached to the kidneys. Therefore the kidney fat in-
dices presented are larger than would have been the case using Riney's
technique.
Fat content of marrow samples from the metatarsals was determined on a wet and dry weight basis by the Department of Animal
Science, Oregon State University, following standard procedures for
ether extraction. The marrows (in situ) were frozen from 45 to 60
days before analysis.
The adrenal glands were dissected from the kidneys, fixed in
ten percent formalin, and stored in 70 percent alcohol. After fat was
removed from preserved adrenals, the glands were blotted dry and
weighed to the nearest 0. 01 gram.
Samples of blood serum were tested for Brucella abortus,
Leptospira pomona, L. canicola, L. icterohaemorrhagiae, and
Anaplasrna marginale by the Veterinary Diagnostic Laboratory,
Oregon State University. The tests employed were the serum plate
agglutination test of the United States Department of Agriculture, the
rapid plate agglutination test, and the
anatest', respectively. The
diagnostic laboratory also checked samples of cervical mucus for
Vibrio fetus (var. veneralis) using culturing, fluorescent antibody,
and cervical mucus agglutination techniques.
Terminology
Pregnancy rate is used to express the percentage of pregnant
females in a sample consisting of adult females (two years and older)
or yearling females. Since elk rarely bear more than one calf
(Kittams, 1953: 18Z and 183), fertility and fecundity are used synonymously with pregnancy rate.
"Diamond Laboratories, Des Moines, Iowa.
Reproductive season refers to the year in which the rut
occurred. This designation was necessary because collections from
cne gestational period often extended over part of two calendar years.
Embryo is used in a broad sense to include specimens in all
phases of prenatal development.
Statistical significance was considered to be at the 0, 05 level
unless otherwise stated.
11
III. RESULTS
Breeding Season
Breeding Seasons of 1967 and 1968
Murie (1951: 125) reported that the active breeding season for
elk occurs from the first part of September to the latter part of
October. His observations were based on intensity of bugling and
other rutting behavior of bulls. Judging from dates calves were
dropped, Schwartz and Mitchell (1945:298) indicated that most breeding of Roosevelt elk on the Olympic Peninsula, Washington, took place
between September 15 and October 15, Based on dates of conception
computed from embryo size, Morrison, Trainer and Wright (1959: 31)
found that 26 (65 percent) of 40 gravid cows collected from two Rocky
Mountain elk populations in Montana conceived between September 26
and October 10, whereas outside dates of breeding were September 16,
and November 4.
Dates of conception were calculated for Roosevelt and Rocky
Mountain elk embryos collected during the 1967 and 1968 reproductive
seasons to delimit the period of the rut, Comparison of respective
distributions of breeding dates for adult cows of both subspecies mdicates that females collected in November generally conceived earlier
than did cows obtained during December and January (Tables 1 and 2),
Table 1. Dates of breeding calculated for adult female Roosevelt elk collected in Western Oregon, 1967 and 1968 reproductive seasons (dates of
collection in parenthesis).
1967 Season
November
(11-18)
Dates of Breeding
No.
1968 Season
January
(6-28, 1968)
No.
Aug. 17-21
Sept.
Oct.
Nov.
6-10
11-15
16-20
21-25
26-30
1- 5
6-10
11-15
16-20
21-25
26-30
31- 4 Nov.
No.
1
Latest
Median
Mean
2
3
5
1
5
2
2
6
3
4
1
4
4
5
1
6
4
"
"
4
5
1
5
1
1
3
2
1
1
1
1
51.3
54.1
67.6
81.1
83.8
1
91.9
94.6
97.3
3
1
1
1
1
1
1
1000
1
Sept. 20
Sept. 24
24
32
Sept. 15
Nov.
Oct.
Oct.
No.
1
2
6
7
7
4
1
3
1
2
1
1
Sept. 5
Oct. 22
Cumulative
Percent
10.8
24.3
40.5
1
3
Post November
3
3
4
Aug. 19
Oct. 30
Sept. 18
Sept. 23
1
12
37
Sept. 22
Nov.
Sept.
Oct.
17
28
7
Aug.
Cumulative
Percent
2.7
1
1
5
"
No.
5
10-14
15-19
Earliest Date
No.
November
1
5- 9
Totals
December
(7-15)
1
22-26
27-31
1- 5
November
(2-22)
1967 & 1968 Seasons
2.8
8.3
25.0
44.4
63.9
75.0
77.8
86.1
88.9
94.4
97.2
97.2
97.2
100.0
36
19
Oct. 30
Sept. 20
Sept. 23
Sept. 15
Nov. 17
Oct. 2
Oct. 5
I-
(")
Table 2. Dates of breeding calculated for adult female Rocky Mountain elk collected in Northeast Oregon, 1967 and 1968 reproductive seasons
(dates of collection in parenthesis).
1967 Season
November
(11-19)
Dates of Breeding
Sept.
Oct.
Nov.
No.
1968 Season
Dec. 11, 67
Jan. 20, 68
No.
6-10
11-15
16-20
21-25
26-30
1- 5
6-10
11-15
16-20
21-25
26-30
31- 4 Nov.
Earliest Date
Latest
"
Median
Mean
"
No.
Dec. 7, 68
Jan. 25, 69
No.
4
3
2
2
11
2
6
4
1
15
2
10
2
1
2
1
2
1
2
1
5
1
2
1
1
1
1
29
Sept. 16
Oct. 24
Oct. 3
Oct. 3
Cumulative
Percent
3.5
7.0
17.5
26.3
45.6
71.9
89.5
93.0
96.5
98.2
100.0
8
5
17
Sept. 10
Oct. 27
Sept. 28
Sept. 28
Sept.
Oct.
Sept.
Sept.
13
17
28
30
11.1
27.8
1
3
44.4
3
61.1
3
72.0
77.8
83.3
88.9
88.9
94.4
100.0
2
1
1
1
1
12
5.6
1
1
28
Cumulative
Percent
No.
1
Sept. 27
Oct.
Oct.
1
Post November
1
6
Nov.
No.
1
1
9
9
6
November
2
2
6
5
2
5- 9
Totals
November
(16-20)
1967 G 1968 Seasons
57
18
Sept. 10
Oct. 27
Oct.
2
Oct.
1
Sept. 13
Nov.
Oct.
Oct.
8
2
1
14
The differences observed could not be attributed to any variation in
time of breeding activity between areas where elk were collected
Although some of the difference in chronologies of breeding dates between the November and post November periods might be explained by
random variation in the small samples, at least one other factor is
apparently also involved.
Inspection of the growth curve for known age elk embryos
(Morrison, Trainer and Wright, 1959) suggests that approximately 20
days postconception is the minimum time needed for embryonic tissue
in elk to become macroscopic, and detectable with the techniques
applied in my study. Since uteri of adult cows were collected begin-
ning November 2, I believe that the consistently earlier cessation of
breeding indicated for November collections resulted primarily from
a failure to identify all conceptions occurring after October 13 (20
days prior to November 2). For the 1967 and 1968 reproductive
seasons combined, distribution of breeding dates determined for cows
collected during the December-January period suggests that six percent (two of 36) and 11 percent (two of 18) of the Roosevelt and Rocky
Mountain elk (adults), respectively conceived after the last breeding
dates indicated by the November collections (Tables 1 and 2)
Conse-
quently,the breeding dates designated for cows obtained in November
probably accurately represent the chronology of rutting activity to
only about 20 days before the first day cows were collected (October
15
13). The distributions of conceptions calculated for the December-
January samples appear then to most accurately describe the breeding season for el.k examined.
The breeding seasons determined for adult Roosevelt and Rocky
Mountain elk during the 1967 and 1968 reproductive seasons (December-
January samples) are similar in most respects. Also the dates of
breeding agree well with the timing of the rut in both subspecies as reported by Murie (1951; 125), Schwartz and Mitchell (1945:298) arid
Morrison, Trainer and Wright (1959: 31).
Although the dates that adult cows were bred evidently was not
related to their age, yearlings usually conceived later than did adults.
For Rocky Mountain elk, the average breeding date for five yearlings
collected during November, 1968 was October 6 (range, September
29 - October 10) compared to September 28 for adults obtained in
November (Table 2). Two gravid yearling Roosevelt elk killed
December 7, 1968 and February 15, 1969 were estimated to have conceived on October 13 and November 10, respectively, whereas the
mean date of breeding for adults obtained in December, 1968 was
October 7 (Table 1).
Physical Condition and Period of Breeding
Verme (1965) reported that the breeding season of adult female
white-tailed deer (Odocoileus virginianus) subjected to extremely poor
16
nutrition from October to late November was later than for does on a
high dietary plane during the same period. The rutting season of female Tule elk (Cervus canadensis nannodes) that McCulloch
and
60)
(1969: 59
studied occurred earlier during years of abundant forage as
compared to years of poor food production. Apparently the nutritional
status of female Roosevelt elk during the fall (as judged by their
physical condition) influenced dates that cows conceived.
For a sample of 25 cows, 3-10 years old, collected during
November,
1968,
females judged in the best physical condition (mdi-
cated by higher kidney fat indices) had earlier breeding dates on the
average than did cows in poorer condition (Figure 2). The relationship between improved physical condition and earlier breeding was
weaker, however, for a collection of 20 cows (3-10 years old)
examined during January,
1968
(Figure 3). But the interval between
time of collection and peak of the respective
about
90
days for cows obtained in January,
and
1968
compared to approxi-
mately 30 days for specimens examined in November,
Consequently, had females collected during January,
examined in November,
1967
ruts was
1967
1968
1968
1968
(Table 1).
been
(thus considerably reducing the effect of
interim environmental factors upon fat deposits) then possibly a stronger relationship between physical condition and time of breeding would
have been apparent for cows obtained in January.
Lactating Roosevelt elk, presumably because of generally poorer
Indices of
Kidney Fat
(Classes)
195_284[
9/10
165 - 194
9/18
0
-
101- 164.
B
I
= Breeding Date (Dry Cow)
= Breeding Date (Wet Cow)
= Mean Breeding Date
9/24
I
63- 100
A
i
I
9/24
32-
A
62I-
9/29
I
1968
August
30
10
September
20
Breeding Dates
30
10
October
20
30
Figure 2. Relationsliip of kidney fat indices and dates of breeding for 25 female Roosevelt elk, 3-10
years old,
collected in Western Oregon, November 2-17, 1968
Indices of
Kidney Fat
(Classes)
81 - 127
°
C)
A
9/30
I
61-80
U
I'
10/10
= Breeding Date (Dry Cow)
= Breeding Date (Wet Cow)
43- 57
A = Mean Breeding Date
9/28
5)
c-.
- 14- 33
C)
A
10/7
I
1967
10
I
20
September
30
Breeding Dates
I
10
I
October
20
30
November
Figure 3.. Relationship of kidney fat indices and dates of breeding for 20 female Roosevelt elk, 3-10 years old,
collected in Western Oregon, January 6-28, 1968.
10
19
physical condition, usually became pregnant later than did nonlactating
females (Figures 2 and 3). Fuller (1966: 21) reported that nonlactat-
ing bison (Birn bison) apparently bred earlier than did cows that were
nur S ing.
Comparison of median dates of conception within the respective
November and post November collections of adult Roosevelt and
Rocky Mountain elk (Tables 1 and 2) suggests that the rut commenced
earlier in 1968 than in 1967. An obvious explanation is that cows were
in better physical condition during the late summer of 1968 than for a
similar period in 1967. Unfortunately, measurements of physical
condition (available only for Roosevelt elk) during the two reproductive
years were recorded at different chronological seasons and are there-
fore not comparable. Nevertheless, other evidence is available which
indirectly suggests an improved nutritional status for cows during the
prerutting period of 1968. Weather conditions prevailing during the
summer of 1967 as compared to 1968 were strikingly different, The
June to mid-September interim of 1967 was one of the driest on
record for Oregon, and observations indicated that plant growth was
severely retarded as a result, Although little precipitation fell from
June to August 10, 1968, unprecedented rainfall occurred subsequently
in August throughout Western and Eastern Oregon, and the production
of forage responded accordingly. It appears, therefore, that earlier
breeding activity apparent for adult female Roosevelt and Rocky
Mountain elk in
1968
20
resulted from improved physical condition be-
cause of greater availability of forage during the prerutting period.
Fertility
Pregnancy Rates
Prior to commencement of the present study it was speculated
that the disparity of pregnancy rates observed between samples of
adult Roosevelt and Rocky Mountain elk was largely attributable to
collection of female Roosevelt elk too early in the season. Possibly
some cows were examined before they were physiologically ready to
ovulate, or more likely, before all embryos actually present were
large enough to allow detection of pregnancy. Three types of evidence
were used to estimate the extent that time of collection influenced
pregnancy rates observed for collections of Roosevelt elk examined
during the five reproductive seasons
(1964-68)
included in this study
(Table 3).
(1) Of the
and
1968
95
adults collected on all areas during
and designated as nongravid, both ovaries of
tioned, Sixty-eight
(86
1965, 1967,
79
were sec-
percent) either lacked corpora lutea, contained
regressing corpora lutea, or were from uteri containing non-viable
embryonic tissue. Therefore these cows could not have been
preg-
nant when killed. The remaining 11 cows with functional corpora lutea
were distributed in the three samples as follows,
1965
- two,
Table 3. Pregnancy rates of Roosevelt elk collected in Western Oregon, 1964-68 reproductive
seasons (collection dates in parenthesis).
No. Examined
No. Pregnant
Pèrcent Pregnant
Area and Reproductive Season Yearling
Adult
Yearling
Adult
Yearling
Adult
Millicoma
1964 (Nov. 28 & 29)0
46
25
54
1965 (Nov. 20 & 2l)/
5
41
0
10
0
24
/
1966 (Dec. 3 & 4)1
1967 (Jan. 3 Feb. 25, 68)
1968 (Nov. 2 Dec. 14)
TOTALS 1964-68
T
7
1
4
38
48
50
'
1
0
0
22.
24
31
14
0
58
50
1
112
0
6
21
1
10
33
48
2.
12
0
8
5
3
0
42
1
17
2.23
3
62.
So
T
1968 (Nov. 17 Dec. 15)
North Coast
1967 (Nov. 11 - 18)
1968 (Nov. 16, 68 Feb,15,69)
TOTALS 1967-68
Totals All Areas 1964-68
5
20
2.5
2.64
Harper, 1965: 7
Harper, unpublished field notes, 1965
Harper, 1967:3
5
33
1
10
20
3
132.
12.
62.
50
50
22
1967 - four, and 1968 - five. Even if all 11 actually were gravid or
were about to ovulate (a doubtful assumption since all were collected
after November 1), changes in the respective reproductive rates would
have been minor. Both ovaries from 14 of 16 nongravid yearlings
killed during 1965, 1967, and 1968 were also examined. None con-
tamed corpora lutea.
(2) Comparison of breeding dates for Roosevelt elk collected
during the November and post November periods of the 1967 and 1968
reproductive seasons combined (Table 1) suggests that if all specimens
obtained in November had been collected in December or later, the
pregnancy rates for samples collected in November would have been
about six percent higher.
(3)
Data on dates of breeding or frequency of ovulation are lack-
ing for the 1964 and 1966 samples of Roosevelt elk. But 54 and 58 per-
cent of the adults included in these samples collected on November 28
and 29, 1964 and December 3 and 4, 1966, respectively were gravid,
compared to a 50 percent pregnancy rate for the sample of adults
examined during January and February, 1968 (Table 3), If it were
true that many pregnancies went unnoticed in uteri collected in late
November and December of 1964 and 1966, respectively, than a lower
fertility rate would hardly be expected from cows autopsied beginning
about three weeks later during January.
The foregoing evidence suggests that some potential
Z3
pregnancies" were not enumerated in Roosevelt elk examined in
November, But the number involved was evidently small and hardly
sufficient to account for the marked difference in reproductive rates
apparent between Roosevelt and Rocky Mountain elk.
One-half, or 13Z of Z64 adult Roosevelt elk checked from 1964
to 1968 were gravid (Table 3). The average rates of pregnancy for
adults from each study area were almost identical, but greater variation appears in ratios of pregnancies observed annually for the respective localities.
Among the ratios of gravid adults recorded for each reproductive
season on the Millicoma area, only the proportion of pregnancies
found in 1965 is indicated to differ significantly from the mean of 50
percent for the area (chi-square
14.93, 4 df--most of difference,
10.95,attributed to 1965 season). As compared to other seasons, re-
productive rates among adults in 1965 were substantially lower for all
ages represented. Furthermore the calf: cow ratio recorded in March,
1967, which reflects the 1966 birthrate corresponding to the 1965
season of reproduction, was only 30: 100 contrasted to an average of
37: 100 for the reproductive years, 1964-67 (Harper, 1969: 2). Con-
sequently, the estimate of pregnancies for 1965 evidently reflects a
change in reproduction (for unknown reasons) rather than age-related
differences in fecundity or random variation.
A ZO percent difference in fertility levels for the 1967 and 1968
24
collections of adult females from the North Coast area (Table 3) is
indicated, but the dissimilarity is possibly due to the small number of
elk studied,
The age specific pregnancy rates of Roosevelt elk studied are corn-
pared in Table 4 with similar data recorded for certain other populations of elk, Of the Roosevelt elk examined, cows from four to ten
years old had the highest pregnancy rates. Few yearlings were
gravid, and none of eight cows judged to be older than ten years were
pregnant. The evidence of a difference in the proportions of pregnan-
cies found among the two and three year olds as compared to the four
to ten year olds was significant (chi-square = 12. 34, 1 df).
The pregnancy rates shown for Rocky Mountain elk collected in
Northeast Oregon are based on cows obtained during the November-
January periods of the 1967 and 1968 reproductive seasons. Comparison of breeding dates for adults killed during the November and post
November periods of both seasons (Table 2) and comparison of pregnancy rates for 68 adults collected in November (85 percent) with the
95 percent rate for 22 adults killed in December and January mdicates that about 10 percent more pregnancies would have been apparent
had all uteri been collected beginning in December,
The proportions of pregnancies indicated for all age classes of
Roosevelt elk except yearlings are lower than those found in all but
one comparable age group of Rocky Mountain elk (Table 4), This
Table 4. Comparison of age-specific pregnancy rates among samples of Roosevelt and Rocky Mountain elk (outside collection dates in parentheses- all years listed as reproductive seasons).
Age in Years
Roosevelt Elk
(This Study)
1965_6&U
(Nov. 2
-
Feb. 25)
Rocky Mountain Elk
Northeast Oregon
(This Study)
1967
&
1968
Jan. 25)
(Nov. 2
1
4
5-7
8-10
11+
33
10
49
74
22
8
13
0
All
2+
Ages
238'
25
27
3
9
Exam.
15
13
23
22
14
16
2
105
90
Preg:
5
12
19
19
14
13
2
84
79
12
% Preg.
Exam.
Michigan
Exam.
'Data
3
Exam.
Preg.
°/ Preg.
N. Yellowstone
(Greer, 1966)
1963-1966
(Oct. 27 June)
(Blouch & Moran, 1965)
1964
(Dec. 5 - 13)
2
Preg.
1/
% Preg.
92
59
43
58
100
86
83
59
0
107
49
45
80
100
81.
213
104
88
104
79
56
62
141
78
74J
584
480
12
75
53
61
138
77
59
475
463
% Preg.
Preg.
30
33
33
29
12
95
98
95
80
99
98
11
21
27
17
20
6
3"
2
16
20
14
17
2
2
18
76
74
82
85
33
67
96
81
105
94
73
71
70
76
for 1965 and 1966 compiled from Harper,(unpubljshed field notes, 1965) and 1967.
V Less than the 289 females listed in Table 3 since 51 of the cows aged during the 1964-66 seasons were assigned to different age groups
than I used.
'Computed from number of specimens and percent pregnant.
Classified as eight and nine year olds.
Classifed as ten and older.
Ui
26
exception seems insignificant, since oniy six adults (ages eight and
ten years, Michigan) are involved. Though a trend is apparent in
collections of Rocky Mountain elk to indicate that the pregnancy rates
of cows four to ten years old are higher than in the other ages, the
differences are much less pronounced than for Roosevelt elk.
The incidence of pregnancies determined from adults in the
three samples of Rocky Mountain elk listed in Table 4 approximate the
74 to 94 percent fertility rates that Kittams (1953: 181) summarized
for 11 samples totaling 2, 072 adult cows collected intermittently from
1935 to 1950 in Yellowstone National Park, Jackson Hole, and Banff
National Park, Canada. Therefore the 50 percent pregnancy rate
calculated for adult Roosevelt elk in Western Oregon (average propor-
tion of gravid adults in Tables 3 and 4) is only one-half to two-thirds
the rates reported for adult cows from other elk herds in North
America.
Incidences of Twinning and Multiple Ovulation
Of 135 pregnancies in Roosevelt elk (Table 3), and 84 in Rocky
Mountain elk (Table 4) checked in my study, all involved only single
embryos. Kittams (1953: 183) reported only five twinnings among
1
,
690 gravid Rocky Mountain elk uteri.
Both ovaries of 83 gravid Roosevelt and 68 gravid Rocky
Mountain elk in the above samples were sectioned. Although the
Z7
ovaries of no pregnant cow contained more than one corpus luteum
over 11 mm in diameter, 78 percent of the gravid Roosevelt elk and
85 percent of the gravid Rocky Mountain elk had developed secondary
corpora lutea (ranging from 3 mm to 10 mm in diameter), which
appeared functional and apparently were the result of postconception
ovulations (Halazon and Buechner, 1956 and Morrison, 1960).
Evidence of Infertility
I conducted an intensive laboratory study of 75 nonpregnant
Roosevelt elk uteri collected during the 1967 and 1968 reproductive
seasons, and Z8 nongravid uteri obtained in 1965 to determine in what
manner infertility was manifested.
Infertility in Yearlings
Sectioning of both ovaries of 14 nonpregnant yearlings revealed
no corpora lutea or corpora albicantia (pigmented scars that deve'1op
from corpora lutea of previous cycles). If the sample of ovaries
examined is typical, it appears that the low incidence of pregnancy
apparent for yearling Roosevelt elk (1Z percent
Table 4) is because
most yearlings do not attain sexual maturity by the second rutting
season of their life.
28
Infertility in Adults
The infertility identified in adult cows was evident as a failure
to ovulate and as embryonic mortality (Table 5).
Anovulation.
Both ovaries of 79 nongravid adults were
examined. At least 18 had not ovulated during the reproductive
season of their collection. Except for one cow with cystic ovarian
follicles, the ovaries of females considered to be anovulatory
appeared normal but lacked corpora lutea or corpora albicantia, Of
the remaining 61 pairs of ovaries, 29 had corpora lutea and 32 showed
only corpora albicantia,
My conclusion that 17 cows with seemingly normal ovaries failed
to achieve estrus is based on the assumption that all corpora albicantia
originated from luteal tissue of the same breeding season as when the
female was killed. Morrison (1960: 306), who studied ovaries from
elk of known breeding history, indicated that many corpora albicantia
were retained for more than one year, and that he was unable to distinguish pigmented scars of previous reproductive seasons from those
of a current season, It appears, then, that some of the 32 adults
whose ovaries showed pigmented scars but no corpora lutea might not
have ovulated within the year. Therefore I consider the 18 cows
listed as anovulatory in Table 5 to be a conservative figure. A more
realistic assessment of the proportion of nongravid adults in this
Table 5. Infertility identified in nongravid adult Roosevelt elk collected in Western Oregon, 1965, 1967 and 1968 reproductive seasons.
Infertility Identified
Uteri
Collection Period
November
20-21; 1965
11-18, 1967
16-17, 1968
2-22, 1968
December
-
February
1/3/68-2/25/68
12/7-12/15/68
Totals by Age Groups
Area
Exam.1
20
7
5
3
3
2
7
Millic.
LoonLk.
21
12
2
2-3 yrs.
23
8
18
4-lOyrs.
11 +
yrs.
Adults
46
10
79
6
1
27k'
'Uteri with both ovaries present.
V.
With corpora lutea.
With corpora albicantia.
Without corpora lutea or corpora albicantia.
'Includes two cows listed as "aged" in 1965 collection
"Specimens with dead embryos omitted from total.
Ovulation"
No.
Millic.
N. Coast
N. Coast
Millic.
18
Possible
Ovulation'
No.
-
-
-
35
Anovulation
No.
°,
8
-
5
-
1
-
1
-
1
-
0
-
Embryo
Mortality
No.
0
0
No.
-
Total
5
1
1
0
-
0
5
5
1
-
6
12
5
7
0
0
-
7
1
-
1
35
-
8
5
5
0
0
8
11
1
50
2
3
30
48
30
1
10
6
6
60
32
41
18
23
2
2
20
2.5
7
39
10
22
34
35
13
30
sample that did not ovulate, more likely should lie somewhere between
23 and 64 percent (the percentage without corpora lutea or pigmented
scars plus the percentage of ovaries containing pigmented scars only.-Table 5).
Embryonic Mortality.
Early embryonic death was readily
apparent in two of the 79 reproductive tracts of nonpregnant adult
Roosevelt elk (Table 5). I consider the incidence of intrauterine
mortality given as minimal for two reasons. First, of the 20 uteri
collected in 1965 that I examined, most had been previously opened
in the field to check for possible pregnancies. Because of the possi-
bility that any embryonic remains present might have been carried
out with fluid released when the uteri were first incised, the chance
of detecting prenatal losses in these specimens was reduced. Secondl.y, early embryonic mortality proved difficult to determine because
circumstances concerned with collection of reproductive tracts precluded a thorough examination of uterine contents while fresh. Most
nongravid uteri obtained in 1967 and 1968 were placed in dry ice or injected with and then placed in AFA within one hour after autopsy to
minimize post mortem changes. Though the latter method provided
the best material for histological study, scrutiny of fresh, unfrozen
specimens would have been more desirable.
The occurrences of prenatal mortality and suspected mortality
in all nonpregnant uteri examined are described in Table 6. Chorionic
Table 6. Description of occurrences and suspected occurrences of embryonic mortality for Roosevelt elk collected in Western Oregon, 1965, 1967
and 1968 reproductive seasons.
Collection
No.
68-118
Date
11-10-68
Age
(Years)
4
Ovarian Examination*
Udder
Wet
Corpora
lutea
albicantia
68-132
12-7-68
11-15
Wet
lutea
albicantia
67-141
11-18-67
Diameter
Description of Uterine Contents
13 mm (f)
4 mm (r)
Mfsc2c: Fragmented remains of chorion (two largest pieces
3 mm (2)
13 mm (f)
2 mm (3)
3 mm (2)
(one ovary lost in coll.)
5
lutea
albicantia
67-62
11-11-67
3
Dry
lutea
albicantia
67-93
11-11-67
3
-
lutea
albicantia
4 mm
10 mm (r)
4 mm
12 mm (f)
4 mm (r)
2 mm (2)
8 mm x 55 mm); embryo not located. Histolog: Chorionic
epithelium undergoing extensive degeneration. Embryo probably
died at about 20-25 days. Diagnosis: Embryonic tissue dead.
Macroscopic: Two frayed pieces of chorion (8 mm x 15 mm and
4 mm x 11 mm); Histolog: Tissue organization lacking, dead
chorionic cells. Diagnosis: Embryonic tissue dead.
Macroscopic: Compact body of tissue (12 mm x 6 mm x 3 mm)
in tip of uterine horn. Histolog: Tissues poorly defined, but
aggregations of nucleated cells the same size as embryonic red
blood cells of healthy chorion apparent. Diagnosis: Embryonic
tissue dead.
Macroscopic: Membranaceous fragments 1 mm to 2 mm in size.
Histolog: Many necrotic cells resembling chorionic cells.
Diagnosis: Embryonic death suspected.
Macroscopic: Membranaceous fragments 1 mm to 3 mm in size.
Histolog: Many necrotic cells resembling chorionic cells.
Diagnosis: Embryonic death suspected.
* (f) and (r) = corpora lutea appearing as functional and regressed, respectively; number of corpora albicantia in excess of one enclosed by parenthesis.
tJ1
32
vesicles of about 20 to 25 days of age were found broken in uteri of
two additional three year old cows collected, November, 1968,
I
could not find an emLryo in one of the chor ions, and the 6 mm embryo
in the other uterus looked less developed than 6 mm embryos associated with normal appearing membranes. Though some fragmentation
of tissues was evident in histological sections of both vesicles, the
structural distortion was less than observed in tissues described in
Table 6. Considering the absence of more definite evidence of tissue
degeneration, and because intrauterine injection of preserving fluid
can rupture embryonic membranes
(B0
W. OGara, personal com-
munication, 1969), both specimens were considered pregnant. As
was probably true for anovulation, the incidence of early prenatal
deaths in Roosevelt elk studied is probably greater than the two percent figure listed in Table 5.
Infertility in Rocky Mountain Elk
Of 17 nongravid Rocky Mountain elk collected in Northeast
Oregon during the 1967 and 1968 reproductive seasons, the ovaries of
two of eight yearlings and eight of nine adults examined contained
corpora lutea (Table 7). A large corpus albicans (4. 5 mm) was ob-
served in the ovaries of the adult specimen that lacked luteal tissue,
thus suggesting that this cow had also ovulated during the current
breeding season, Nonviable embryonic tissue (similar circumstances
Table 7. Infertility identified in nongravid Rocky Mountain ell collected in Northeast Oregon, 1967 and 1968 reproductive
seasons.
Infertility Identified
Age
Collection Period
Uteri
Exam)'
Ovulation'
No.
Possible
Ovu1ation
No.
Embryo
Anovulation1
No.
Mortality
No.
Total No.
Yearlings
Nov. 11-19, 1967
0
0
4
2
0
2
8
2
0
Nov. 12, 1967
1
0
Nov. 16, 1967
Dec. 22, 1968
3
ii, 1967
Nov. 16, 1968
4
0
4
6
0
6
1
0
0
0
2
0
0
1
1
3
3
0
0
0
0
2
2
0
0
0
0
9
7k"
1
1
Nov. 17, 1968
Totals
Adults
2-3 yrs.
4-10 yrs.
Nov.
11 + yrs.
Totals
_.
U Uteri with both ovaries present.
ai.
With corpora lutea.
'With corpora albicantia.
'Without corpora lutea or corpora albicantia.
"Appearance of dead chorion similar to 68-132 (Table 6).
Specimen with dead embryo omitted from total.
1
0
34
as for 68-132 -- Table 6) was found in one of the adults exhibiting a
functional appearing corpus luteum,
If the small sample of nongravid Rocky Mountain elk examined
is representative, it appears that the frequency of anovulation, among
adults at least, is much less than for the Roosevelt elk studied.
Factors Influencing Fertility
Pathology
Diseases Associated with Reproduction,
Brucellosis, lepto-
spirosis, and vibriosis cause substantial losses to reproduction in
livestock, and acute infections of anaplasmosis in cattle frequently
result in abortion (Gibbons, 1968:396). Rush (1932: 372) found evi-
dence of brucellosis in elk from Yellowstone National Park, Serological reactors of Leptospira pomona have been found among white-tailed
deer (Odocoileus virginianus) (Trainer and Hanson, 1960: 44), and
anaplasmosis has been produced experimentally in white-tailed deer,
black-tailed deer (Odocoileus hemionus columbianus), mule deer
(0. Ii. hemionus), and Rocky Mountain elk (Howe and Hepworth,
1965: 114).
Samples of blood obtained from 109 female Roosevelt elk killed
or captured on the Millicoma area during January, February, March,
and November, 1968 were tested for brucellosis (Brucella abortus),
35
leptospirosis (Leptospira pomona, L, canicola, and L. icterohaemorrhagiae), and Anaplasma marginale. All samples gave nega-
tive reactions for brucellosis and leptospirosis. Additionally,
vibriosis (Vibrio fetus var, veneralis) was not detected among 4Z cultures of cervical mucus collected from females killed in November,
.:
Almost
80
percent of the serum samples obtained from
collected between January and March,
1968
66 cows
reacted positively to a
capillary tube agglutination test (CA) for the carrier state of anaplas -
mosis, Because of the high reaction rate and the failure to find the
organism in red blood cells, Dr. Dean Smith of the Veterinary Diagnostic Laboratory (Oregon State University) concluded that the serological test used was not valid for elk blood. Of 47 serum samples
from cows killed in November,
1968,
only two, or four percent were
positive for anaplasmosis. Since both collections of sera originated
from the same localities and were collected and processed identically
by the same technician, the results cast further doubt on the accuracy
of the CA test for elk serum, Howe et al,
(1964)
has also reported on
the inaccuracy of the capillary tube agglutination test as a method for
diagnosing anaplasmosis in several species of wild ruminants, including elk,
Abnormalities in Uteri and Ovaries
The only abnormality
recognized among uteri and ovaries of 6 yearling and
ZZ9
adult
36
Roosevelt and Rocky Mountain elk in which the uterus and both ovaries
were available for study, was an occurrence of cystic ovarian follicles
in an eight year old, nongravid Roosevelt elk that was dry when killed
on the Millicoma area, Two cystic follicles measuring 40 mm x 40
mm and 4 mm x 20 mm occupied all of the right ovary, whereas the
left ovary looked normal, and contained 13 follicles from 2 mm to 8
mm in diameter and a 1.5 mm pigmented scar. The condition of the
ovaries strongly suggested that ovulation had not occurred earlier in
the season. When considering that cystic ovarian follicles are cornmonly associated with impaired fertility in dairy cattle (Merck, 1967:
852), it seems likely that conception was prevented in this elk for the
same reason.
Male Coverage
To measure the sufficiency of male coverage as related to
fertility of females, calf: cow and bull: cow ratios during 1950-69 were
compared. Although essentially no change was apparent in the pro-
portion of calves recorded throughout the 20 year period, the ratio of
bulls observed from 1950 to 1959 is over twice the ratio from 1960 to
1969 (Table 8). The decline in bulls is related to substantial increases
in numbers of elk hunters and regulation changes allowing harvest of
yearling males. If the fertility of cows was depressed because of insufficient male service, then the apparent production of calves should
37
also drop with the decreased percentage of bulls. Because this has
evidently not occurred, it appears that the present supply of bulls is
ample for reproduction, and that the relatively low pregnancy rates
observed in Roosevelt elk cannot be attributed to inadequate male
coverage.
Table 8. Ratios of bulls and calves per 100 cows recorded annually
for Roosevelt elk in Western Oregon between December and
mid-February, l95O-7OJ/
Number Classified
Period
Cows
1950-59
1960-69
1950-69
l966-70'
No. per 100 cows
Bulls
Calves
Bulls
7,964
19,974
1,704
1,517
3,215
8,307
21
40
8
42
27,938
14,470
3,221
11,522
12
41
701
5,962
5
41
Calves
Compiled from 1950-70 Annual Game Reports, Oregon State Game
Commission,
7/
Period corresponding to reproduction seasons of study.
Physical Condition
Indices of Physical Condition,
The physical condition of female
Roosevelt elk collected during the 1967 and 1968 reproductive seasons
was measured to relate condition of the animal with fertility. Because
of the limited time available for examination of elk in the field, and
for other reasons to be discussed, indices of kidney fat, marrow fat
(metatarsal) and adrenal weight were selected to assess physical
i:i
condition of the Roosevelt elk studied. (Measurements of fat depots
and adrenal weights were not obtained from samples of Rocky Mountam
elk,)
Riney (1955) compared several indices for quantifying fat depots
in red deer (Cervus elaphus) and documented the use of fat reserves
as an indicator of condition for several species of animals, He states
(p. 430-431)
The fact that fat in ruminants appears to be largely endogenous makes it a particularly useful index of metabolic
level and potential energy reserves of the animal, and it
is here postulated that fat can be taken as a direct measure
of the condition, reflecting the metabolic level or goodness
of physiologic adjustment of an animal with its environment.
Of the indices he studied, Riney concluded that the kidney fat
index (weight of the fat around the kidney expressed as a percentage
of the weight of the kidney) best reflected seasonal changes in fat re-
serves among both sexes of red deer. Riney (1955: 435) found that fat
depots in femur marrow apparently were not mobilized until after
depots of subcutaneous and visceral lipids were mostly exhausted.
Consequently, variations in the fat content of femur marrow occurred
only for deer in the lower half of Riney's scale of ideal condition (p.
446).
Ransom (1965) compared the percentage of fat in femur marrow
with kidney fat indices of 34 female white-tailed deer killed between
December and April in Manitoba, Canada. His data showed that the
39
kidney fat index decreased to about 30 with little change in fat content
of femur marrow, but after this point was reached, femur fat decreased markedly. Ransom also found that decreases in kidney fat
when indices fall below 30 were irregular relative to percentages of
femur fat, He concluded that the kidney fat index was a satisfactory
indicator of physical condition at values at or above 30, but recommended using femur fat to assess condition when kidney fat is less
than 30. Anderson, Medin, and Ochs (1969: 337) estimated the percent of fat in carcasses of 18 wintering mule deer using seven different
indices, and concluded that the kidney fat index was probably the most
useful if based on sufficient sample size. They reported a correlation
coefficient of 0.67 between percent kidney fat and percent ether-
extractable fat in the carcasses of deer examined.
The relative size of the adrenal glands is considered an indicator of stress in various species of mammals including deer (Hughes
and Mall, 1957; Welch, 196Z). Christian and Davis (1955: 177) be-
lieve that adrenal cortical hormones are mainly involved in counter-
acting the effects of stress stimuli, and that changes in the amount of
adrenal cortex are related to the quantity of cortical hormones produced. Therefore the amount of adrenocortical tissue like the size of
fat reserves should provide measurement of the physical condition of
the animal.
Yearlings, two years old, and cows older than ten years are
40
considered separately from other females in comparisons of physical
condition and fertility. Because all pregnancies in yearl&ngs and
many in two year olds were associated with puberty (Table 4), lactation and other physiological conditions resulting from previous pregnancies would be absent as factors affecting conception in these ages.
Similarly, cows older than ten years (all nonpregnant) are excluded
from comparisons of animal condition and reproduction since factors
concerned with senility might be responsible for their nongravid
status.
Indices of Kidney and Marrow Fat.
The kidney fat indices and
values of percent ether-extractable fat in metatarsal marrow of 95
female Roosevelt elk, three years and older, collected during the 1967
and 1968 reproductive seasons are shown in Figures 4 and 5.
Meta-
tarsal marrow was analyzed instead of femur marrow because it was
impractical to remove samples of femur marrow from elk shot by
hunters, Both plots indicate the same general relationship between
kidney fat and the fat content of metatarsal marrow as Ransom (1965)
described for kidney and femur fat in deer,
When the reproductive condition of cows (3-10 years old) is
considered relative to fat stores it is apparent that pregnant females
had larger deposits of kidney and marrow fat than nonpregnant cows
(Figures 4 and 5). Females with a kidney fat index above 60 had a 93
percent pregnancy rate, those with an index between 59 and 30 showed
A
I.,
: .
® . ®
.
S
80
60
4OL©
I
A
= Pregnant (Nonlactating)
Nonpregnant (Nonkctating)
o = Lactating
20
-= 11+years
40
80
120
160
Kidney Fat Index
200
240
280
Figure 4. Kidney fat indices plotted against percentage of fat
(wet basis) in metatarsal marrow for 54 female Roosevelt
elk, 3 years and older, collected in Western Oregon, November 2 - December 15, 1968.
female
120
1968.
-
Index Fat Kidney
60
.
A
A
40
A
20
80
60
20
28, 3 January Oregon, Western in collected older, and years 3 elk, Roosevelt
metatarsal in basis) (wet fat of peentage against plotted indices fat Kidney 5. Figure
41 for marrow
80
0
LI
Lactating
A
years +
Nonpregnt
100
(NOfliactating)
S
(Nonlactating) Pregnant
.
1
43
a 50 percent pregnancy rate, and only ten percent of the females with
kidney fat values under Z9 were gravid. Low reproductive rates also
coincided with percentages of fat in the metatarsal marrow under
about 85.
Using stepwise multiple linear regression, kidney fat indices of
89 females, 3-10 years old, listed in Figures 4 and 5 were compared
against effects of age, reproductive status, status of lactation and
month of collection. Because elk were collected on the three study
locations at different periods during each reproductive year, compariSons of fat reserves between areas or years were not possible. The
influence of age on kidney fat deposits was negligible (p > 0. 50), but
gravid cows has significantly greater fat depots than nongravid cows
(p < 0.001), and lactating females showed significantly less kidney fat
than nonlactating cows (p < 0.001).
Measurements of kidney fat deposits were obtained from eight
yearlings and nine two year old Roosevelt elk. Though the sample is
small, gravid females had higher average indices of kidney fat than
nongravid females (Table 9).
Lactating cows had lower pregnancy rates than nonlactating females in the collections of Roosevelt elk examined. In a sample of
60 cows, 3-10 years old, collected during November and December,
1968 for which data on lactation are available, 51 percent of the wet
cows were gravid compared with 84 percent of the dry females
Table 9. Indices of kidney fat for yearling and two year old female Roosevelt elk collected in Western Oregon, 1968 reproductive season; all
specimens nonlactating.
Kidney Fat Indices: (Number Cows in Parenthesis)
Yearlings
Two Year Olds
Pregnant
Collection Period
Range
November 2-17, 1968
December 7-15, 1968
Nonpregnant
Pregnant
Nonpregnant
Mean
Range
Mean
(0) -
-
(6) 35-123
71
(3) 101-198
152
(5) 73140
(1) -
96
(1) -
19
(1) -
175
(0) -
Range
Mean
Range
Mean
110
45
(Table 10). A chi-square test showed that the evidence of a difference in pregnancy rates between wet and dry cows was significant
(chi-square = 6.80, 1 df).
The proportions of lactating cows in samples of Roosevelt elk
(3-10 years old) collected in November, December and January, 1968
were: 24 of 42 (57 percent), 11 of 18 (61 percent), and 17 of 42 (40
percent), respectively (Table 10). The similar percentages of wet
cows recorded during November and December, 1968 as compared to
the substantially lower incidence of lactation observed in January,
1968 suggests that many females ceased lactating in January. Because
gravid and nongravid females might not 'dry up" at similar rates,
comparison of pregnancy rates between wet and dry cows are probably
least biased for specimens obtained during November and December.
Examination of udders of 65 Rocky Mountain elk, three to ten
years old, collected during November and December, 1967 and 1968
also revealed a lower incidence of pregnancy among wet cows (82 percent) as contrasted with dry cows (100 percent -- Table 11). But the
indicated difference in pregnancy rates between lactating and non-
lactating cows (18 percent) was not significant (chi-square = 2.00,
1 df) and is considerably less than the 33 percent difference recorded
for Roosevelt elk collected in November and December, 1968 (Table
10).
The comparison of fat deposits with reproductive status in
Table 10. Relationship of pregnancy rates and status of lactation for Roosevelt elk, 3-10 years old,
collected in Western Oregon, 1967 and 1968 reproductive seasons.
Lactating
Nonlactatirig
Number
Number
Number
Number
Collection Period
Examined
Pregnant
Examined
Pregnant
1967 Reproductive Season
January 3-28, 1968
17
7
2.5
16
1968 Reproductive Season
November 2-22, 1968
2.4
13
18
16
December 7-15, 1968
11
5
7
5
Totals by Months
November-December
35
18
25
21
Percent Pregnant
January
Percent Pregnant
Totals 1967 and 1968
Reproductive Seasons
Percent Pregnant
51
17
25
7
16
41
52.
25
64
50
37
74
0"
Table 11. Relationship of pregnancy rates and status of lactation for Rocky Mountain elk, 3-10 years
old, collected in Northeast Oregon, 1967 and 1968 reproductive seasons.
Collection Period
Lactating
Number
Number
Examined
Pregnant
1967 Reproductive Season
November 11-19, 1967
December 11-22, 1967
21
16
3
3
1968 Reproductive Season
November 2-20, 1968
December 7-31, 1968
26
22
6
56
Totals 1967 and 1968
Reproductive Seasons
November-December
Percent Pregnant
NonLac tat ing
Number
Examined
Number
Pregnant
4
4
5
3
3
46
9
9
82
100
A
Roosevelt elk studied reveals a positive relationship between physical
condition and fertility. The relationship was apparent in females with
pregnancies less than 30 days advanced as well as in cows during
later stages of gestation. Therefore it is doubtful that the larger fat
stores typical of gravid cows accumulated as a result of physiological
factors associated with pregnancy. More likely, the difference observed in fat depots between pregnant and nonpregnant Roosevelt elk
(3-10 years old) reflects factors such as lactation which affect the female before conception.
Indices of Adrenal Weight.
Hughes and Mall (1957: 194) found
that adrenal weights of Z7 adult female black-tailed deer (Odocoileus
hemionus columbianus) collected during early November in California
were reasonably well correlated (r = -0. 57) with four classes of physical condition (based on determinations of kidney fat). The animals
they studied were from a population believed to be in excess of the
carrying capacity of the habitat. They concluded (p. 195) "that in the
deer sampled adrenal cortical size, most easily measured as adrenal
weight, may be considered as a condition factor with regard to the
field condition determinants presently in use, "
The relationships between adrenal weights in 76 female
Roosevelt elk, 3-10 years old, collected during the 1967 and 1968 reproductive seasons and variables of season, age, pregnancy, lactation
and percent metatarsal fat were analyzed using stepwise multiple
49
linear regression.
Simple coefficients of correlation resulting from the analyses
are presented in Table 12. The direction (sign) of the relationships of
adrenal weight versus variables of fat depots, pregnancy and lactation
agree with interactions previously described between fat reserves,
pregnancy and lactation. The strong positive correlation between un-
adjusted adrenal weight and age probably reflects the effect of body
weight on adrenal size, since the weight of cows in the 3-10 year age
group also generally increased with age (C. E. Trainer, unpublished
data, 1969).
Of the three indices used to express adrenal size (Table 12),
relative adrenal weight expressed as centigrams of adrenal tissue per
pound of hog-dressed carcass weight generally resulted in the strong-
est correlation with other variables, except for age. (Unless otherwise stated, relative adrenal weight as used in reference to Roosevelt
elk will refer to the adrenal weight: hog-dressed weight ratio.
The quantitative importance of the independent variables shown
in Table 12 to relative adrenal weight in the stepwise regression is
indicated by the R2 values in Table 13. Among the variables analyzed
during both seasons, only lactation, which accounted for 32 percent
(R2
x 100) of the variation in relative adrenal weight in the January,
1968 sample, substantially influenced adrenal size. The relationships
shown were not improved by similar analysis using kidney fat indices
Table 12. Correlation coefficients (r) computed from
correlation of three indices of adrenal weight with variables listed for female Roosevelt elk,
3-10 years old, collected on Millicoma area, 1967 and 1968 reproductive seasons.
Reproductive
Season'
Adrenal Weight
lnd1ces/
Kidney
Me
Pregnancy
Lactation
Fat
Index
Percent Fat
Metatarsal
Marrow
(Wet Basis]
Percent Fat
Metatarsal
Marrow
(Dry Basis)
A
g Adrenal
(Unadjusted wt)
0. 65
-0.08
0. 38
-0.27
-0. 22
B
cg Adrenal per
lb Body wt
-0.20
0.47
-0.01
0.45
-0.27
-0.36
-0.23
0.53
-0.04
0.56
-0.32
-0.40
-0. 29
A
0. 42
(Nov. 2-Dec. 14, 1968y"
-0. 13
0.02
-0.07
-0.02
0.22
-0. 19
B
No. Examined 39
-0.27
0.06
-0.21
0.24
-0.12
C
-0.27
-0.03
0.13
-0.28
-0.14
-0.01
A
0.53
-0.05
0. 17
-0. 16
0.34
-0.22
-0. 18
B
-0. 16
0. 22
C
-0.27
0.37
-0.32
-0.18
-0. 23
0. 30
-0.36
-0.39
-0. 30
1967
(Jan. 3-28, 1968)
No. Examined 37
C
1968
1967-1968
No Examined 76
eg Adrenal per
lb Hog-dressed
Body wt/
'Collection dates in parenthesis.
'Based on total weight of both adrenals.
'Hog-dressed weight is carcass weight with all viscera removed, but with head, hide and feet attached.
'Thirty-seven specimens collected November 2-16; remaining two collected December 14.
51
Table 13. Coefficients of determination (R2) and F values resulting from stepwise multiple linear regression analysis of adrenal weight:hog-dressed body weight ratio Y on variables listed for
female Roosevelt elk, 3-10 years old, collected on Millicoma area, 1967 and 1968 reproductive seasons.
Reproductive
Season
1967
(Jan. 3-28, 1968)
No. Examined 37
Array of
VariablesX
Lactation
1968
No. Examined 39
1'
-'
Individual
R
2
2/
0.315
0.462
0.482
0.487
0.315
0.147
0.019
0.005
18.49
8.65
1 13
0.31
Marrow (Wet)
0. 487
0.003
0.02
Marrow (Dry)
0.489
0.001
0.01
Kidney Fat
Age
Pregnancy
0.081
0.042
Percent Fat
Metatarsal
Marrow (Wet)
Percent Fat
Metatarsal
0.081
0.123
0.158
0.034
3.18
1.67
1.35
0.170
0.013
0.49
Lactation
0. 178
0.186
0.008
0.008
0.31
0.31
0. 155
0. 155
15. 85
0.301
0.332
0.031
KidneyFat
Percent Fat
Metatarsal
Marrow (Dry)
1967-1968
No. Examined 76
R2
Age
Pregnancy
Percent Fat
Metatarsal
(Nov. 2-Dec. 14)
Cumulative
Percent Fat
Metatarsal
Marrow (Wet)
Age
Year
Lactation
Percent Fat
Metatarsal
Marrow (Dry)
Kidney Fat
Pregnancy
0.264
0.336
0.337
0.337
0.109
0.037
0.004
0.000
0.000
11.23
3.83
3.14
0.45
0.04
0.00
x 100 = percent of variation in dependent variable Y that is attributable to combined effects of
independent variables X.
= ratio of individual R2/df to residual of individual R2/df.
'Thirty-seven specimens collected November 2-16; remaining two on December 14.
52
truncated down to 40 to remove the affect of very fat cows upon relative adrenal weight.
Consequently, it appears that adrenal size, as measured by
weight at least, in Roosevelt elk examined was largely determined by
factors not included in the regression analyses.
53
IV.
DISCUSSION
The pregnancy rate of 50 percent determined for adult Roosevelt
elk examined apparently represents the fertility level in adults during
approximately the initial three months of gestation (through January).
Knowledge concerning the extent of prenatal losses between
January and time of parturition would be desirable, especially since
there are conflicting reports about the incidence of fetal mortality in
elk during the late winter and spring.
Greer (1966: 124) mentions that the difference between an 89 per-
cent rate of pregnancy for 642 adult Rocky Mountain elk collected from
the northern Yellowstone herd, November 21, 1961-February 15,
1962 and an 80 percent pregnancy rate for 89 adults killed February,
21 to June 12, 1962 might suggest that intrauterine losses occurred.
But he further states (ibid)
that evidence of resorption or recent abortion was not found
in any of the spring specimens. The lower fertility rate was
due to the large representation of older, and usually barren,
females in the sample. Nearly 50 percent were eight years
or older.
Murie (1951: 142), however, reports that although pregnancy rates of
about 90 percent prevailed among large samples of adult Rocky Mountam
elk killed in the Jackson Hole-Yellowstone National Park area
during December and January, 1935-36 and January, 1943, examination of hundreds of elk that died during the late winter indicated that
54
about 50 percent of the adult cows were nonpregnant. He concluded
(ibid) that
It is true that these were animals that had died, and that the
same proportions may not have applied to the rest of the herd,
yet this pregnancy rate may have been significant. If so,
then it is a fact that about hail the cows do not produce calves
in the spring. This is affirmed to some extent by field observations in the spring.
Although only three female Roosevelt elk were collected after
January (one 10-15 year old and one yearling, February 25,
both nongravid, and one gravid yearling, February 15,
1968 --
1969),
prenatal
losses occurring in Roosevelt and Rocky Mountain elk after about
January were calculated using an indirect method.
The presence of milk in an udder is evidence that the cow was
nursing during the period before she was collected. Because substan-
tial numbers of calves are apparently not weaned until after December,
the incidence of lactation during November and December should serve
as a measurement of the proportion of cows with calves at heel during
that time of the year. For Roosevelt elk, the pregnancy rate of 55
percent for 44 cows, 2-10 years old, examined on the Millicoma area,
January,
1968
closely approximates the 57 percent incidence of lacta-
tion recorded for 42 cows, 3-10 years old, collected on the same area
the following November and December. Similarly, the pregnancy rate
of
87
percent for 39 Rocky Mountain elk, 2-10 years old, killed in
Northeast Oregon, November,
1967
to January,
1968
was identical to
55
the 87 percent lactation rate recorded for 32 cows, 3-10 years old,
obtained during November and December, 1968 throughout the same
region.
Though some mortalities of fetuses and/or calves undoubtedly
occurred in Roosevelt elk between January and November, 1968, none
were indicated in the comparison of indices of pregnancy and subsequent lactation. But, as 34 of 39 Rocky Mountain elk uteri examined
were collected during November, and because it was indicated previously that about ten percent of the "potential pregnancies" in adult
females of this subspecies killed in November were not enumerated,
it is likely that a fertility rate greater than 87 percent prevailed in
Rocky Mountain elk uteri examined in November. Thus some losses
of fetuses and/or calves were indicated for this subspecies. The relationship apparent between pregnancy and subsequent lactation rates
for both Roosevelt and Rocky Mountain elk suggests that incidences of
pre and postnatal losses happening between about January and Novem-
ber, 1968 among elk 2-10 years old were minor. Consequently, it
appears that pregnancy rates determined for Roosevelt and Rocky
Mountain elk during the December-January period, 1967-68 closely
approximated the birthrate for 1968.
The indicated decline in the proportion of bulls in Roosevelt elk
herds (a result of increased harvests) coupled with no apparent decrease in calf: cow ratios (Table 8) strongly suggests that the relatively
56
low reproductive rate recorded for the subspecies in western Oregon
originated with the female.
None of 14 nonpregnant yearlings whose ovaries were examined
had ovulated. The evidence of infertility observed in the sample of 79
nongravid adults intensively studied was apparent as embryonic mortality (minimum of two percent) and ovulation failure (23 to 64 per-
cent -- Table 5), The reason(s) for the nongravid status of about onethird of the cows in this sample whose ovaries contained corpora lutea
are more difficult to explain. Since functional appearing luteal tissue
was observed in 11 of the 27 nongravid specimens which had ovulated
(Table 5), it is possible that a few of these cows actually were gravid,
but that the embryo was insufficiently developed for macroscopic detection. But it is also possible that some corpora lutea resulted from
a silent heat period, in which ovulation occurred without normal behavioral estrus and subsequent copulation. Silent heat is common
among farm mammals (Hafez, 1968: 324), and Simkin (1965: 744) pre-
sented data indicating that, apparently because of silent heat periods,
many ovulations occurring in moose (Alces alces) early in the breed-
ing season do not result in fertilization.
Although data obtained in my study do not rule out a greater
occurrence of mortality of embryonic tissue (including phases concerned with fertilization of ova) than recorded, the evidence cited
above suggests that most of the nongravid Roosevelt elk examined did
57
not experience estrus, or at least what is considered as a normal
estrus.
Considering that indices of physical condition reflect stresses
affecting the animal, the strong relationship apparent between physical
condition and fertility indicates that the low pregnancy rates prevailing
in Roosevelt elk examined resulted from the effect of environmental
factors adverse to fertility. Unknown factors might have been operating to the detriment of physical condition. But the positive correla-
tion between fat stores, which serve as energy reserves for the animal (Riney, 1955: 430), and fecundity suggests that the ultimate cause
of low fertility levels observed in Roosevelt elk was the stressing
effect of a nutritional plane inadequate for sustaining reproduction at
a high level. In the discussion to follow it is understood that the food
resources available to the animal, as well as utilization of nutritive
stores within its body are subject to considerable modifications by
weather conditions.
The effect of nutrition on reproduction in elk examined was mani-
fested in different ways. As discussed, initiation of rutting activity
was possibly influenced by forage conditions during 1967 and 1968.
The apparent manner in which the plane of nourishment affected
fertility in female Roosevelt elk appeared to vary according to age
groups.
Since corpora lutea or corpora albicantia were not found in the
ovaries of six of 11 two year olds or in two of ten three year olds
examined, it is likely that a delay in puberty was responsible for
the nongravid condition of about 38 percent (eight of Zi) of the two and
three year old females studied.
For sexually mature cows, the positive relationship revealed
between fertility and physical condition, plus the significantly lower
pregnancy rates indicated for wet cows strongly suggests that nursing
resulted in a reduction of nutritive stores to a level apparently mimical to reproduction. The effect of lactation on fecundity indicates a
general pattern of every-other-year breeding in many adult female
Roosevelt elk. That is, a cow which is suckling a calf during the
summer will enter the breeding season with lower energy reserves
than if she were dry. The chances of her conceiving are therefore
lessened. But because of nonlactation during the succeeding summer,
her energy stores will be high in the fall and conception more likely.
The variation in percentages of gravid adults recorded annually on the
Millicoma area, 1964-68 (Table 3) reinforces the observation that
many cows of breeding age are pregnant only on alternate years. It
appears that the pregnancy rates apparent in 1964 (54 percent), 1965
(Z4 percent) and 1966 (58 percent) reproductive seasons on the area
reflected such a breeding pattern, presumably as a result of factors
inimical to the physical condition of the female (hence reproduction)
during 1965. (A chi-square test comparing pregnancy rates for the
59
two reproductive seasons of lowest fertility (1965 and 1967) with the
three highest (1964, 1966 and 1968) indicated that the difference was
significant - - chi-square = 8. 92, 1 df.) The proportion of adults
breeding every-other-year is expected to vary relative to the impact
of such factors as weather upon food supplies and stored energy re-
serves.
Since all of eight female Roosevelt elk over ten years of age
were nongravid (Table 4), it appears that reproduction in very old
cows was particularly susceptible to the effects of impaired nutritional
intake.
The findings of this study agree with results of other investiga-
tions concerning the influence of nutrition on fertility in cervids. The
works of Buechner and Swanson (1955 - - Rocky Mountain elk),
Pimlott (1959 -- moose), Daniel (1963 -- red deer) and Verme (1967 --
white-tailed deer) all relate the importance of food intake to attainment
of puberty. Verme (1967) presented evidence demonstrating that stress
from lactation lowered fertility in white-tailed deer, and Lowe (1969:
440) found that the pregnancy rate of nonlactating red deer was mdi-
cated as significantly higher than for lactating hinds.
Studies concerning reproduction in mule deer (Longhurst,
Leopold and Dasmann, 1952: 57; and Julander, Robinette and Jones,
1961) and white-tailed deer (Verme, 1967) indicate that the nutritional
level prior to and during the breeding season was directly related to
the rate of ovulation. The apparent effect of lactation upon fertility
in Roosevelt elk clearly suggests that the months of June through
November (period before and during the rut) are, from the nutritional
standpoint, of critical importance to reproduction in this subspecies.
However, food conditions during the winter are probably also signif-
icant to fecundity, especially as related to the onset of puberty, as
has been indicated for moose (Pimlott, 1959: 398) and Rocky Mountain
elk (Greer, 1966: 1Z8).
When fertility rates of adult Rocky Mountain elk (88 percent
pregnant) and adult Roosevelt elk (49 percent pregnant -- Table 4)
collected in Oregon are compared in light of the indicated effect of
nutrition on reproduction for the latter subspecies, it appears that
Rocky Mountain elk were afforded a better nutritional regime than
were Roosevelt elk. I believe this might be the case for two reasons.
First, weather conditions prevailing in the habitat of the two sub-
species are strikingly different, The climate of areas inhabited by
Roosevelt elk in Western Oregon is characterized by mild tempera-
tures, prolonged cloudy periods and heavy rainfall, which contrasts
sharply to the warmer summers, colder winters and lower precipitation typical of the climatic environment affecting Rocky Mountain elk
in Northeast Oregon. Therefore it is probable that weather conditions
common to Western Oregon, particularly the higher amounts of rainfall and fewer days of sunshine, affect either the nutritive content of
61
forage eaten by Roosevelt elk, or in other ways stress the physiology
of the female to the ultimate impairment of fertility. As winter
temperatires are milder and snowfall less in Roosevelt elk habitat of
Western Oregon than on the Rocky Mountain elk ranges of Northeast
Oregon, one might conclude that weather conditions in the winter
should enhance physical condition in Roosevelt elk. Actually the con-
trary might be true. Several stockmen with whom I have talked mdicated that it is more difficult to fatten cattle in the wet climate typical
of the interim, October through March in Western Oregon, than in the
colder but drier weather prevailing in Eastern Oregon during the
same period.
No data are available on comparative population densities of
Roosevelt and Rocky Mountain elk in Oregon. This is unfortunate
since the higher fecundity typical of Rocky Mountain elk might also be
the resuLt of greater abundance of forage per individual because of
fewer elk per unit of habitat than for Roosevelt elk. Buechner and
Swanson (1955) related an apparent increase in natality among yearling
Rocky Mountain elk to greater availability of nutrition per animal be-
cause of a lower population density resulting from increased harvests.
62
V. CONCLUSIONS
Comparison of the average pregnancy rate recorded for adult
Roosevelt elk examined during 1964- 68 reproductive seasons (50 per-
cent -- Table 3) with the mean calf:cow ratio observed during the
respective winters following these seasons (41 percent - - Table 8),
indicates that the proportion of calves recorded was largely determined by the level of fertility rather than postnatal mortality. It is
evident that the low fertility rates found in female Roosevelt elk were
not caused by inadequate male service or diseases. The apparent
relationship between physical condition and pregnancy for cows ex-
amined indicates that the fertility levels observed in female Roosevelt
elk ultimately resulted from a lack of nutrition, or failure of the fe-
male to maintain nutritive stores necessary for a high rate of reproduction. Lactation was identified to be the major factor affecting
energy reserves of the cow to the detriment of fertility.
Assuming that genetic differences among subspecies are not responsible for variation in reproduction between Roosevelt and Rocky
Mountain elk, it appears that the fertility rate observed in Roosevelt
elk is limited either by (1) qualitative deficiencies in nutrition resuiting from climatic influences or (2) by quantitative shortages in
forage because of too great a density of elk. Therefore it seems important that measurements be obtained concerning the effect of various
63
population densities of Roosevelt elk upon fertility and net productivity
the percentage of animals remaining after mortality from causes
other than harvest has been deducted (Pimlott, 1959:393)]. If fewer
elk per unit of habitat would ultimately increase the number of animals
available for cropping, then harvesting of antlerless elk would be
justified. But if gains in net productivity did not result from lower
population densities then the fertility level apparent for Roosevelt
elk probably represents the maximum productivity possible under
existing environmental conditions.
64
LITERATURE CITED
Anderson, A. E. , D, K. Medin and D. P. Ochs. 1969. Relationships
of carcass fat indices in 18 wintering mule deer. Proc. Western
Assoc. State Game and Fish Commissioners 49:329- 340,
Armstrong, R. A. 1950. Fetal development of the northern whitetailed deer (Odocoileus virginianus borealis Miller). Am.
Midi. Nat. 43(3): 650-666,
Batchelor, R. F. 1965. The Roosevelt elk in Alaska, its ecology and
management. Federal Aid in Wildlife Restoration Project
W-6-R-5, Work Plan D. Alaska Dept. of Fish and Game. 3'7p.
Blouch, R. I. and R. J. Moran. 1965. 1964 elk hunt. Res. and
Development Rep. No. 30. Michigan Dept. of Conserv. 24p.
Buechner, H. K. and C. V. Swanson, 1955. Increased natality resulting from lowered population density among elk in Southeastern Washington. Trans. N. Am. Wildi. Conf. 20: 560-567.
Christian, J. J. and D. E. Davis. 1955. Reduction of adrenal
weights in rodents by reducing population size. Trans. N. Am.
Wildl. Conf. 20:177-189.
Daniel, M. J. 1963. Early fertility of red deer hinds in New ZeaLand.
Nature 200: 380.
Fuller, W. A. 1966. The biology and management of the bison of
Wood Buffalo National Park. Wildl. Mgmt. Bull. Ser. 1, No,
16.
Canadian Wildl. Sev. SZp.
Gibbons, W. J. 1968. Viral, rickettsial and protozoan infections.
In: Reproduction in farm animals (Ed. E. S. K. Hafez).
Zd ed. pp. 381-401. Philadelphia, Lea and Febiger Co. 44Op.
Greer, K. R.
Fertility rate of Northern Yellowstone elk
populations. Proc. Western Assoc. State Game and Fish Commissioners 46: 123-128.
1966.
Guyer, M. F. 1953. Animal micrology. 5th ed. Chicago, University of Chicago Press, 327p.
65
Hafez, E. S. E. 1968. Reproductive failure in females. In: Reproduction in farm animals (Ed. E. S. E. Hafez) pp. 321-341.
2d ed. Philadelphia, Lea and Febiger Co. 44Op.
haLCtzon, G. C. and H. K. Buechner, 1956. Postconception ovulation in elk. Trans. N. Am. Wildl, Conf. 21: 545-554,
Harper, J. A.
1965. Ecological study of Roosevelt elk. Federal
Aid Project W-59.-R-2, Job No. 1. Oregon State Game Commission. lOp.
Harper, J. A.
1967,
Harper, J. A.
1969. Ecological study of Roosevelt elk.
Ecological study of Roosevelt elk. Federal
Aid Project W-59-R-4, Job. No. 2. Oregon State Game Commission. 3p.
Federal
Aid Project W-59-R-6, Job No. 3. Oregon State Game Commission. 7p.
Howe, D. L., W. G. Hepworth, F. M. Blunt and G. M. Thomas.
1964. Anaplasmosis in big game animals: experimental infection and evaluation of serologic tests, Am, J, Vet. Res. 25:
1271-1275.
Howe, D. L. and W. G. Hepworth. 1965. Anaplasmosis in big game
animals: tests on wild populations in Wyoming. Am. J. Vet.
Res. 26: 1114-1120.
Hughes, E. and B. Mall. 1957. Relation of adrenal cortex to condition of deer. Calif. Fish and Game 44(2): 191-196.
Julander, 0., W. L. Robinette and D. A. Jones. 1961, Relation of
summer range condition to mule deer herd productivity. J.
Wildi. Mgmt. 2 5(1): 54-60.
Kittams, W. H. 1953. Reproduction of Yellowstone elk. J. Wildl.
Mgmt. 17(2): 177-184,
Longhurst, W. M., A. S. Leopold and R. F. Dasmann. 1952. A
survey of California deer herds, their ranges and management
problems. Calif. Dept. Game and Fish, Game Bull, No. 6,
l36p.
Lowe, V. P. W. 1969. Population dynamics of the red deer (Cervus
elaphus) on Rhum. J. Anim. Ecol. 38(2): 425-457,
Mace, R. U. 1956. Oregon's elk. Wildi. Bull. No. 4. Oregon
State Game Commission. 33p.
McCullough, D. R. 1969. The tule elk, its history, behavior, and
ecology. Univ. Calif. Pub. Zool. 88:1-191.
Merck and Company. 1967. The Merck veterinary manual. 3d ed.
Rathway, N. Jer. , Merck and Co. l674p.
Morrison, J. A. , C. E. Trainer and P. L. Wright. 1959, Breeding
season in elk as determined from known-age embryos. J.
Wildl. Mgmt. 23(1): 27-34.
Morrison, J. A. 1960. Ovarian characteristics in elk of known
breeding history. J. Wildl. Mgmt. 24(3): 297-307.
Murie, 0. J.
1951. The elk of North America. Harrisburg, Pa.
Stackpole Co. and Wildl. Mgmt. Inst., Washington, D. C.
Pimlott, D. H. 1959. Reproduction and productivity of Newfoundland
moose. J. WildI. Mgmt. 23(4): 381 -401,
Quimby, D. C. and J. E. Gaab. 1957. Mandibular dentition as an
age indicator in Rocky Mountain elk. J. Wildl, Mgmt. 2 1(4):
435 -451.
Ransom, A. B. 1965. Kidney and marrow fat as indicators of whitetailed deer condition. J. Wildl. Mgmt. 29(2): 39 7-398,
Riney, T. 1955. Evaluating condition of free-ranging red deer
(Cervus elaphus), with special reference to New Zealand, New
Zealand J. Sci. and Tech., Sec. B. 36(5): 429-463.
Rush, W. M. 1932. Bang's disease in the Yellowstone National Park
buffalo and elk herds. J. Mammal, 13(4): 371 -372,
Schwartz, J. E. and G. E. Mitchell. 1945. The Roosevelt elk on the
Olympic Peninsula, Washington, J. Wildi. Mgmt. 9(4): 295319.
Simkin, D. W. 1965. Reproduction and productivity of moose in
Northwestern Ontario. J. Wildl, Mgmt. 29(4): 740-750,
67
Trainer, D. 0. and R. P. Hanson. 1960. Leptospirosis and
brucellosis serological reactors in Wisconsin deer, 1957-1958,
J. Wildi. Mgmt. 24(1):44-5Z.
Verme, L. J.
1965. Reproduction studies on penned white-tailed
deer. J. Wildi. Mgmt. Z9(1): 74-79.
Verme, L. J.
1967. Influence of experimental diets on white-tailed
deer reproduction. Trans. N. Am. WildI. and Natur. Resour.
Conf. 32:405-4Z0.
Welch, B. L. 196Z. Adrenals of deer as indicators of population conditions for purposes of management. In: Proc. First National
White-tailed Deer Dis. Sympo. pp. 94-108. Athens, Georgia,
S. E. Sec. Wildi. Soc. ZOip.
.
APPENDIX 1
Data resulting from examination of ovaries and uteri for Roosevelt
elk collected in Western OregQn, 1965, 1967 and 1968 reproductive
seasons.
Symbols:
L and R = left and right uterine horn (location of embryo).
cR/FR
= crown-rump or forehead-rump length of embryos.
r
= regressed corpus luteum,
Where more than one corpus luteum is indicated for a pregnant
cow, the smaller presumably resulted from a postconception
ovulation (Halazon and ,Buechner,
1956).
Table A. Ovarian and uterine data--pregnant Roosevelt elk collected on Millicoma area, November 20 and 21, 1965.
Collection
No.
Date
Age
(Years)
Corpora lutea
Diameter in mm
Udder
(Left (Right)
ovary) ovary)
Embryo
Corpora Albicantia No.
2mm
2-4mm
Follicle No.
4-1-mm
2-5mm
5-8mm
8+mm
Uterine
Total
horn
CR/FR
mm
Sex
(Ovarian Exam. Complete)
65-is
-31
-33
-45
-62
-25
-74
-27
11/20
11/20
11/20
11/20
11/21
11/20
11/21
11/20
4
4
4
4
4
5
5
6
-
-
2
2
1
8
7
2
0
-
1
is,
15,
16,
17,8
15,
14,
14,7
13,7
0
0
1.
4
6
18
2
0
1
1(9mm)
1
0
6
8
19
11
3
0
14
0
0
0
0
0
0
3
1
8
1(9mm)
3
12
26
0
11
0
0
0
12
29
0
8
1
1
8
2
0
1
1
0
0
-
1
1
7
0
0
0
3
(Ovarian Exam. Incomplete)
-55
-61
11/20
11/21
4
4
-
17,
*(65-15, 25, & 45) Embryo damaged in storage.
0
(left ovary only)
(right and part of left ovary)
5
-
R
R
70-80
*
68
73
M
60-70
105
70-80
F
M*
F
F*
36
L
80
R
25
-
-
66
M
M
Table B. Ovarian and uterine data--pregnant Roosevelt elk collected on Millicoma area. January 6-28, 1968
Collection
No.
Date
Age
(Years)
Udder
Corpora Lutea
Diameter in mm
(Left
(Right
ovary)
Embryo
Corpora Albicantia No.
ovary) <2mm
2-4mm
4+mm
Follicle No.
2-5mm
5-8mm
8+mm
Uterine
Total horn
CR/FR
mm
Sex
(Ovarian Exam. Complete)
68-6
-4
-7
-17
-22
-23
-25
-30
-45
-5
-14
-32
-13
-29
-34
-36
-44
67-131
68-16
-24
-37
-8
-26
1/6
1/7
1/6
1/13
1/14
1/14
1/14
1/20
1/28
1/6
1/7
1/21
1/7
1/20
1/21
1/21
1/27
1/18
1/13
1/14
1/27
1/6
1/20
2
3
3
4
4
4
4
4
4
5
5
5
6
6
6
6
6
8
8
8
8
9
10
Wet
Dry
Dry
Dry
Wet
Wet
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Wet
Wet
Dry
Wet
16,
15,5
17,8
16,7
-
9
16,
5
18,7
18,
7
19,
18,
18,6
17,5
18,4
-
1
1
0
0
0
16,
0
0
0
0
0
0
0
1
0
7
17
5
14
0
0
2
1
1(8mm)
1(9mm)
1(10mm)
1
0
1
0
1
1
11
0
2
0
1
21
0
3
3
0
0
0
0
0
25
8
1
0
24
2
12
36
36
2
0
16,
16,
-
18,
6
4
-
17,6
0
7
1
2
0
4
0
0
1
0
0
0
0
20,3
-
0
14,
18,
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
14
2
1
1
1
0
1
13,
17,
2
1
0
0
0
0
1(8mm)
2(8mm)
0
0
1(12mm)
0
1(9mm)
1(9mm)
8
17
8
16
16
L
21
R
R
R
-
F
M
M*
37
R
15
L
34
254
F
L
261
35
M
R
F
21
L
335
238
213
272
202
194
236
F
F
151
F
-
3
2
1
19
5
17
3
0
20
R
1
11
1
0
0
19
0
14
0
12
20
R
1
1
0
15
R
1(9mm)
M
M
M
174
M
L
L
L
31
1
F
37
24
26
10
27
14
2
0
192
168
186
289
205
103
284
292
226
218
232
177
139
13
31
6
6
1(11mm)
13
20
18,8
-
1
7
F
F
M
F
M
F
M
M
M
M
(Ovarian Exam. Incomplete)
-20 1/13
10
Dry
-0
0
0
*(68-22) Anterior end of mandible 5 mm shorter than opposing cranial surface.
(right ovary only)
Table C. Ovarian and uterine data--pregnant Roosevelt elk collected on Miflicoma area, November 2 - December 14, 1968.
Corpora Lutea
Collection
Age
Date
(Years) Udder
(Ovarian Exam. Complete)
No.
68-85
-98
-139
-79
-87
-91
-89
-97
-112
-125
-94
-96
-102
-105
-107
-84
-99
-100
-101
-104
-116
-82
-88
-92
-115
-75
-77
-95
-106
-73
-126
11/3
11/8
12/14
11/2
11/3
11/3
11/3
11/7
11/10
12/14
11/5
11/6
11/9
11/9
11/9
11/3
11/8
11/9
11/9
11/9
11/10
11/3
11/3
11/4
11/10
11/2
11/2
11/6
11/9
11/2
12/14
2
2
2
3
3
3
4
4
4
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
4
Dry
S
Dry
Wet
Dry
Dry
Wet
Wet
Dry
Wet
Dry
Dry
Wet
Wet
Dry
Wet
Dry
5
5
5
5
6
6
6
6
6
6
7
7
7
7
8
8
8
8
9
9
Wet
Dry
Wet
Dry
Wet
Dry
Diameter in mm
(Left
(Right
ovary)
16,6
ovary) <2mm
15,8
14,
12,4
13,7
16,
-
5
15,
12,
6
14,7
10,3
6
12,3
15,7
-
-
1S,6
16,7
15,7
14,
Corpora Albicantia No.
12,
14,7
12,4
14,6
13,6
14,6
0
2-4mm
0
0
0
1
2
0
0
0
0
0
0
0
0
0
0
14
14
2
18
3
5
2
6
1
2
1
0
9
1
0
0
0
1
0
0
19
14
25
3
1
0
0
0
0
0
1
1
0
0
1
1
0
0
0
0
0
7
1
1
0
0
41
3
0
8
3
1
0
0
0
0
0
0
15,9
1
0
15,
17,
1
28
1
11,
14,8
0
0
0
0
0
14
0
0
0
0
14,6
0
5-8mm
1
2
12,
14,6
0
0
2-Smm
14
17
0
15,7
4+mm
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Embryo
Follicle No.
54
12
12
29
16
14
9
16
27
13
26
37
12
26
1
2
4
1
1
4
0
1
2
2
3
2
8+mm
0
l(Smm)
0
l(llmm)
l(9mm)
l(lOmm)
l(llmm)
0
0
l(Smm)
l(lOmm)
0
0
l(9mm)
0
1(8mm)
0
2(9mm)
l(Smm)
l(lOmm)
l(lOmm)
0
0
1
0
4
0
1
1
3
11
0
23
1
8
5
31
3
l(lOmm)
l(9mm)
0
1(10mm)
l(Omm)
0
0
Total
Uterine
horn
CR/FR
mm
30
15
R
30
16
16
22
L
35
L
57
8
L
8
L
50
54
102
16
18
12
L
15
22
16
30
55
14
16
-
6
R
15
31
R
18
17
R
L
24
69
74
70
L
88
12
19
29
14
30
39
14
29
12
L
R
5
R
11
R
133
R
4
13
55
R
L
R
L
Sex
-
M
M
-
50
M
M
F
-
R
L
L
13
15
50
L
53
L
33
25
13
R
L
39
34
L
44
(68-85, 112 & 84) Gelatinous exudate in cervix or vagina.
/68_107) Chorion much fragmented; embryo appearing less developed than 6 mm embryos associated with unfragmented membranes.
4,(6882) Chorion much fragmented; embryo not located.
',(68-92) Embryo lost in field; chorion recovered from uterus.
' (68-115) The 4 mm corpus luteum appeared to be regressing; confirmed by histological examination.
82
M
Table D. Ovarian and uterine data--pregnant Roosevelt elk collected on North Coast area, November 11-18, 1967.
Collection
No.
Date
Age
(Yearsl
Udder
Corpora Lutea
Diameter in mm
Corpora Albicantia No.
(Left
(Right
ovary) ovarr) 2mm
2-4mm 4+mm
Embryo
Follicle No.
2-5mm
5-8mm
Uterine
Total horn
CR/FR
-
8+mm
mm
Sex
(Ovarian Exam. Complete)
67-72
-139
-54
-79
-66
11/11
11/18
11/11
11/11
11/15
2
Dry
3
4
4
5
-
Dry
Dry
15,
14,
13,
5
0
0
5
8
17,
0
15,6
1
0
1
2
0
5
1
0
0
0
0
0
9
1
4
1
22
13
23
3
0
0
1(11mm)
11
0
0
5
25
l(l5mm)
l(8mm)
14
24
L
-
R
4
78
86
23
F
58
-
-
-
-J
Table E. Ovarian and uterine data--pregnant Roosevelt elk collected on North Coast area, November 16 and 17, 1968 and February 15, 1969.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Diameter in mm
Udder
(Left
ovary)
Embryo
Corpora Albicantia No.
(Right
ovary) <2mm
2-4mm
4+mm
Follicle No.
2-5mm
5-8mm
84-mm
Uterine
Total horn
CR/FR
mm
Sex
(Ovarian Exam. Complete)
68-156
-163
-172
-208
-209
2/15
11/17
11/17
11/16
11/16
1
2
4
4
6
Dry
Dry
Dry
Wet
11,
14,
7
-
0
13,
14,
16,
0
0
1
0
1
1
0
0
26
13
30
1
8
1
0
0
1
0
22
1
-
-
-
(both ovaries cut off)
0
0
2
1
0
1(9mm)
0
l(9mm)
1(9mm)
26
16
L
192
L
3
31
R
R
27
26
-
-
R
27
10
24
F
-
-*
(Ovarian Exams Incomplete)
-180
11/16
*(68-209) Embryo
5
lost
Dry
-
in field, thorion recovered from uterus.
-J
Table F. Ovarian and uterine data--pregnant Roosevelt elk collected on Loon Lake area, November 17
December 15, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Year)
Diameter in mm
Udder
(Left
ovary)
(Right
ovary)
Embryo
Corpora Albicantia No.
<2 mm
2-4mm
4+mm
Follicle No.
2-5mm
5-8mm
8+mm
Total
UterineCR
horn
mm
Sex
(Ovarian Exam. Complete)
68-148
-133
-121
-129
12/14
12/7
11/17
12/7
-136 12/7
-147 12/14
-134 12/7
-135 12/7
-151 12/15
-127 12/7
-143 12/14
1
2
4
4
4
4
5
S
5
7
7
Dry
Dry
Dry
Wet
15,5
14,7
Dry
Wet
Dry
Dry
Wet
Wet
Wet
14,
12,
13,
14,8
8
16,10
15,9
0
0
0
0
0
0
0
0
0
2
1
0
8
0
1
9
0
0
2
3
1
2
0
15,5
17,
16,5
1
1
0
0
1
1
0
0
0
0
1
0
16
19
19
14
6
19
18
20
15
20
11
1(9mm)
1(10mm)
18
R
1
21
2
0
L
21
L
1
1
1
1
3
4
2
1
1
1(9mm)
1(12mm)
2(10mm)
1(8mm)
1(11mm)
0
0
1(11mm)
1(10mm)
17
72
83
75
R
110
9
R
21
L
115
32
4
107
22
24
17
22
13
L
L
R
120
R
101
-
116
F
M
M
F
F
-
-
M
F
M
F
-J
Table G. Ovarian and uterine data- -nonpregnant Roosevelt elk collected on Millicoma area, November 20 and 21, 1965. *
Corpora Lutea
Collection
Age
Date
(Years)
(Ovarian Exam. Complete)
No.
65-17
-66
-67
-8
-46
-70
-14
-63
-71
-12
-18
-73
-24
-58
-72
-4
-6
-51
-9
-20
-64
-22
-35
11/20
11/21
11/21
11/20
11/20
11/21
11/20
11/21
11/21
11/20
11/20
11/21
11/20
11/20
11/21
11/20
11/20
11/20
11/20
11/20
11/21
11/20
11/20
Diameter in mm
Udder
(Left
ovary)
(Right
ovary)
1
-
-
-
1
-
-
-
1
-
-
-
2
2
-
-
-
2
-
-
-
3
4
<2mm
0
0
2-4mm
0
0
-
0
0
-
0
0
-
2
-
1
-
-
0
2
0
0
0
0
-
-
1
1
1
-
0
1
0
1
-
0
1
1
2
2
1
1
7r
4r
1
21
-
-
0
-
-
-
1
-
-
-
0
-
1
0
1
1
1
0
1
0
0
-
1
13
0
3
7
7
Aged
Aged
6r
6r
-
Adult
Adult
-
7r
0
-
-
0
5r
0
-
-
1
-
-
0
15
0
-
-
30
27
22
16
16
28
17
14
15
15
4
5
1
21
0
0
12
0
12
1
-
5
5
6
6
6
7
2-5mm
16
0
0
0
0
0
4
4
7r
Follicle No.
4+mm
0
0
0
3
3
Corora Albicantia No.
12
4
15
0
0
22
2
0
0
0
0
0
0
0
0
0
2
13
1
5-8mm
0
2
1
0
1
3
0
0
0
2
0
1
1
1
2
1
3
2
1
0
1
2
1
(Ovarian Exam. Incomplete)
-30
-10
-36
-5
-7
11/20
11/20
11/20
11/20
11/20
2
8r
3
3
4
4
0
0
0
1
1
1
8+mm
l(lOmm)
0
0
l(9mm)
1(l0mm)
0
1(9mm)
l(9mm)
l(lOmm)
Total
17
14
22
31
29
25
17
16
0
0
0
0
0
17
30
17
15
16
16
0
0
0
0
22
15
6
16
0
0
0
23
l(9mm)
1(9mm)
7
1
4
14
(right ovary only)
(right & part of left ovary)
(left ovary only)
(
(right ovary only)
*Uteri (nongravid) from two yearlings, two two year olds, two three year olds, one four year old, and one five year old were examined for pregnancy
at checking station, but are excluded from table since the specimens were not available for reexamination.
-
-
-
0
Table H. Ovarian and uterine data--nonpregnant Roosevelt elk collected on Millicoma
area, January 3
February 25, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Years)
::eter
Udder
ovary'
(Ovarian Exam. Complete)
68-57
-43
-2
-18
-40
-1
-21
-33
-35
-3
-41
-9
-15
67-132
68-11
-12
-19
-31
67-130
68-42
-58
-38
2/25
1/28
1/3
1/13
1/27
1/3
1/14
1
2
3
3
3
4
4
1/21
1/21
5
5
1/6
1/27
1/6
1/7
1/10
6
7
7
8
1/7
8
1/13
1/19
1/20
1/2.5
1/27
2/25
1/28
6
8
9
9
11-15
11-15
11-15
15+
Dry
Dry
Dry
Dry
(Right
ovary)
-
1
-
-
0
-
1
-
0
-
-
12,
3
0
-
3
2
0
0
1
1
0
0
0
0
1
1
2
0
0
Dry
Wet
Wet
Wet
Dry
Wet
Dry
Dry
0
0
0
0
0
0
0
0
0
0
-
-
-
12,
6r
-
0
0
2
-
-
-
-
0
0
0
0
-
-
0
-
-
0
-
(Ovarian Exam. Incomplete)
-10
-27
-28
1/7
1/20
1/21
4
5
7
Dry
Dry
Wet
-
7,
-
68-40, 9, 15, 19, 31 & 28) Gelatinous exudate in cervixor vagina.
(68-10) Corpus luteum forming in ruptured follicle.
0
0
0
3
0
0
0
0
0
0
0
1
2
1
1
1
1
0
2
0
0
5-8mm
37
22
17
1
2
1
21
1
22
32
28
2
11
1
4
26
2
0
0
1
0
1
1
26
0
0
1
0
3
1
0
0
1
2-5mm
14
12
0
0
Follicle No.
4+mm
-
Wet
Dry
2-4mm
0
0
0
-
Dry
Wet
Wet
Wet
Wet
<2mm
-
Wet
Dry
Dry
Corpora Albicantia No.
1
24
12
7
30
1
1
0
0
0
20
1
23
0
1
0
0
2
(right ovary only)
(
"
"
(
"
"
)
"
)
8+mm
0
0
0
0
0
1(14mm)
0
Total
38
24
18
221
33
28
13
7
1(10mm)
1(9mm)
0
0
27
14
1(9mm)
2.5
0
0
1(12mm)
0
0
0
0
0
0
0
2'
13j'
14
30
1
24
0
2
V
Table I. Ovarian and uterine data--nonpregnant Roosevelt elk collected on Millicoma area, November 2
December 14, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Years)
(Ovarian Exam. Complete)
68-76
11/2
1
-83
11/3
1
-103
11/9
1
-111
11/10
1
-74
11/2
2
-78
11/2
2
-86
11/4
2
-110
-80
-108
-109
-118
-120
-81
-90
-93
-117
-122
-72
-113
-123
-124
11/10
11/2
11/9
11/10
11/10
11/16
11/2
11/3
11/5
11/10
11/18
11/2
11/10
11/22
12/14
2
3
4
4
4
4
5
5
5
5
Diameter in mm
Udder
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Wet
Wet
Wet
Wet
Dry
Wet
Dry
11-15
11-15
Wet
Wet
Wet
Wet
Wet
(Ovarian Exam. Incomplete)
-114
11/10
8
Dry
6
8
9
(Left
ovary)
(Right
ovary)
-
-
-
5r
-
11 r
4r
-
.
-
-
-
13,4 r
-
11, 4r
6r
6r
-
4r
15,
4r
-
6r
-
-
-
Corpora Albicantia No.
<2mm
2-4mm
Follicle No.
4+mm
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
1
0
0
2
0
5-8mm
10
2
21
2
40
20
10
20
0
3
4
2
8+mm
Total
12'
1
0
1(8mm)
1(9mm)
0
24
4111
23
15
1(11mm)
1(8mm)
1(9mm)
232,
0
0
0
1311
14'
11
2
0
18
13
33
2
1
0
0
0
1
8
0
0
1(10mm)
1(9mm)
19
2
0
164
3
0
4
1(12mm)
1(9mm)
0
20
17
1
1
0
0
0
0
18
1
7
0
0
0
0
0
0
1
1
0
0
0
1
0
0
0
0
0
0
0
1
0
0
1
2-Smm
1
14
17
12
13
4
9
9
6
4
11
0
2
1
1
0
1
20
1(11mm)
0
9'4
35
l5
4'
10
0
1(9mm)
0
0
2
0
2
0(left ovary only;
10k,
6'
6
right cystic) J
(68-76, 103, 80, 109, 122 & 123) Gelatinous exudate in cervix or vagina.
/68-86) Corpora lutea had macroscopic appearance of being functional, but histological examination indicated both were regressing.
(68-118) Embryonic mortality--fragments of disintegrating chorion present in tips of both uterine horns; histological examination showed necrotic
,,tissue structure; embryo not located.
,(68_118 & 81) Indicated status of corpora lutea verified by histological study.
(68-114) Right ovary contained two cystic follicles, 40 mm x 40 mm, and 4 mm x 20 mm, respectively.
Table J. Ovarian and uterine data-nonpregnant Roosevelt elk collected on North Coast area, November 11 - December 6, 1967.
Collection
No.
Date
Age
(Years)
Udder
Corpora Lutea
Diameter in mm
(Left
(Right
ovary)
ovary)
Corpora Albicantia No.
<.2mm
2-4mm
(Ovarian Exam. Complete)
67-137
-56
-138
-58
-62
-77
-93
-128
12/6
11/11
11/16
11/12
11/11
11/11
11/11
11/11
calf
1
1
2
3
3
Dry
Dry
Dry
Dry
Dry
Wet
3
11-15
Wet
0
0
-
-
-
4r
12,
-
lOr
12,
0
0
0
0
0
0
0
0
0
Follicle No.
2-5mm
4+mm
0
0
5-8mm
22
10
18
0
0
Total
1
0
23
1
0
11
2
24
1
1
3
1
1
1
1
2
0
24
0
1
1
0
0
27
0
0
0
0
48
8+mm
0
0
1(11mm)
1(9mm)
0
1(10mm)
0
20
5
28
25
48
(Ovarian Exam. Incomplete)
-92
-141
11/18
11/18
4
5
-
-
-
-
-
1
1
(right ovary only)2
(left ovary only)
'(67-62 & 93) Suspected embryonic mortality--uterus contained membrane fragments (1 mm to 3 mm) that histologically resembled chorionic
tissue.
'(67-l41) Embryonic mortality--densely compacted tissue mass 12 mm x 6 mm x 3 mm present in tip of right uterine horn; histological examination
revealed many nucleated red blood cells that resembled embryonic red blood cells of healthy thorion.
Table K. Ovarian and uterine data--rionpregnant Roosevelt elk collected on North Coast
area, November 16 and 17, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Udder
Diameter in mm
(Left
(Right
ovary)
ovary)
(Ovarian Exam. Complete)
68-207
-210
-174
-181
-173
11/16
11/17
11/16
11/16
11/17
1
1
2
4
8
Dry
Dry
Dry
Corpora Albicantia No.
(2mm
0
-
Wet
11,
10,
-
-
-
-
0
0
1
0
2-4mm
0
0
4+mm
Follicle No.
2-5mm
1
0
0
0
1
0
19
7
1
3
0
9
20
5-8mm
2
0
8+mm
0
1(9mm)
1
0
1
1(9mm)
0
1(l0mm)
Total
11
21
20
9
4
0
Table L. Ovarian and uterine data--nonpregnant Roosevelt elk collected on Loon Lake area, December 7-15, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Diameter in mm
Udder
(Left
ovary)
(Ovarian Exam. Complete)
68-144
-146
-149
-142
-130
12/14
12/14
12/15
12/14
12/7
12/14
12/7
4
Dry
Sr
-152
12/15
4
Wet
-
-138
-141
-137
-128
12/7
12/14
12/8
5
5
6
7
7
Wet
Wet
Wet
Wet
Wet
Wet
-131
-145
-150
-132
1217
12/15
12/7
calf
1
1
2
3
Dry
Dry
Dry
Dry
Dry
3
11-15
(Right
ovary)
Corpora Albicantia No.
(2mm
0
5r
6r
4r
11
4r
6r
4r
13,
0
0
0
2
2-4mm
Follicle No.
4+mni
2-5mm
0
0
0
0
0
14
1
0
1
0
9
7
0
3
1
0
0
2
0
0
1
0
1
1
4
1
1
3
3
0
0
2
2
1
1
1
3
0
2
0
0
27
12
5-8mm
0
1
1
0
0
1
8+mm
0
l(l0mm)
0
Total
0
l6ti
10
1(8mm)
1(10mm)
28
1(12mm)
22
l(8mm)
8
14,,
21
0
37
1
1(9mm)
39
9
1
30
28
19
1(8mm)
11
2
0
0
32
3
16
10
0
1
1
1(12mm)
0
2(9mm)
2
31
20
173
l3
L'(68_149) Gelatinous exudate in cervix or vagina.
30 & 152)
Indicated status of corpora lutea verified by histological examination.
'(68-132) Embryonic mortality--two pieces of disintegrating chorion (8 mm x 15 mm & 4 mm x 11 mm)
present in uterus; histological study showed
tissue to be necrotic, and that corpus luteum was apparently functional.
E31
APPENDIX Z
Data resulting from examination of ovaries and uteri for Rocky
Mountain elk collected in Northeast Oregon, 1967 and 1968 reproductive Seasons.
Symbols:
L and R = left and right uterine horn (location of embryo).
CR/FR
= crown-rump or forehead-rump length of embryos.
r
= regressed corpus luteum.
Where more than one corpus luteum is indicated for a pregnant
cow, the smaller presumably resulted from a postconception
ovulation (Halazon and Buechner, 1956).
Table A. Ovarian and uterine data--pregnant Rocky Mountain elk collected in Northeast Oregon, November ii, 1967
january 20, 1968.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Udder
(Ovarian Exam. Complete)
67-213 il/il
2
Wet
-222 11/12
2
Dry
-223
-243
-13
-14
-170
-172
-211
-220
-221
11/11
3
3
3
3
3
3
11/il
3
-224 11/11
11/12
-240 11/12
-248
1/20
-173 11/11
-212 11/12
-216 11/19
-225 11/11
-247 12/Il
-234 11/12
-242 11/11
-229 11/12
-233 11/11
-215 11/19
-218 11/19
-230 11/12
-214 11/13
-228 11/12
-189 11/13
Dry
Dry
Wet
2
12/21
11/11
11/11
11/11
11/11
3
-231
3
3
3
4
4
4
4
4
5
S
6
6
7
Wet
Wet
Wet
Wet
Wet
Wet
Dry
Wet
Dry
-
Wet
Wet
Wet
Wet
Wet
Wet
Wet
Dry
Wet
8
8
9
9
11-15
ovary)
Wet
7
7
15,9
13,
13,
13,
10,
-
10
14,
13,7
14,
6
8
8
7
16,
9
14,7
14,
6
13,4
0
0
2
0
41
1
1
1
1
1
0
11
1
15
14,7
13,7
1
1
0
0
0
0
1
1
1
2
0
41
2
3
0
0
0
0
0
0
2
6
1
0
0
2
44
20
22
27
14
22
10
16
20
0
0
0
8
8
16,
37
19
73
0
0
0
0
0
0
0
13,
1
1
1
0
0
2
2
0
0
14,6
0
0
0
0
16,
14,
0
0
1
1
15,
13,
13,
12,
2-5mm 5-8mm
0
0
0
7
15,7
0
2
7
Follicle No.
2-4mm 4+mm
0
13,10
14,
15,
<2mm
7
10
8
Embryo
Corpora Albicantia No.
13,
13,
18,
5
Dry
Dry
ovary)
13,
Dry
2
11/12
12/22
Diameter in mm
(Left
(Right
0
2
0
0
1
0
0
1
0
1
21
0
1
1
0
0
0
0
1
1
1
2
1
1
1
0
3
0
1
3
17
16
0
3
1
29
19
13
0
0
1
0
1
11/18
12/16
1/19
1/16
1/16
11/12
3
4
4
Wet
Wet
5
5
10
13,5 r
8
Dry
0
-
12,
-
2
0
2(8mm)
1(9mm)
0
38
1
1
6
7
0
0
1
1
0
-
1(9mm)
0
0
1(8mm)
1(9mm)
1(9mm)
1(8mm)
0
1(9mm)
0
1(9mm)
1(8mm)
3
23
44
0
-
0
27
25
0
1
1(9mm)
1(8mm)
1(8mm)
0
0
-
42
12
16
2
0
-
0
0
23
19
1
0
38
0
0
2
1
3
0
(left ovary only)
0
0
1(9mm)
"' )
(gravid uterus, lost after cell.)
(
'
"
Total
l(lOmm)
1(9mm)
1(9mm)
2
(Ovarian Exam, Incomplete)
-164
-258
-68
-66
-67
-232
81-mm
(left ovary only)
(embryo oniy collected)
(right & part of left ovary)
Uterine
horn
20
73
45
21
23
29
15
24
12
CR/FR
L
29
R
R
29
27
L
17
149
116
L
R
-
L
R
L
R
R
L
11
42
32
20
14
R
15
245
21
21
25
19
18
25
22
L
31
26
40
24
47
7
L
R
L
R
R
R
R
R
L
L
R
18
13
32
37
18
19
26
23
75
20
17
R
25
7
L
6
-
F
6
26
36
12
13
L
L
F
16
18
22
R
Sex
mm
-
F
-
F
-
R
-
111
97
F
L
15
-
M
PD
Table B. Ovarian and uterine data--pregnant Rocky Mountain elk collected in Northeast Oregon, November 16, 1968 -January 25, 1969.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Diameter in mm
Udder
(Ovarian Exam. Complete)
67-178 11/16
1
Dry
68-232 11/16
1
Dry
68-318 11/17
1
Dry
68-330 11/18
1
Dry
67-275 12/22
2
Dry
67-280 12/7
2
Dry
68-267 11/19
2
Wet
68-280 11/16
2
68-303 12/20
2
68-332 11/17
2
Dry
67-273 12/22
3
Wet
67-281 12/8
3
Dry
68-268 11/18
3
Wet
68-281 11/16
3
Wet
68-284 11/18
3
Wet
68-336 11/18
3
Wet
67-184 11/16
4
Wet
67-277 12/8
4
Wet
67-282 12/7
4
Dry
68-233 11/17
4
Wet
68-234 12/8
4
Wet
68-279 11/16
4
Wet
68-286 11/16 4
Wet
68-287 11/16
4
Wet
68-289 11/16
4
Wet
68-323 11/20
4
Wet
68-324 11/20
4
Wet
68-317 11/17
5
Wet
(Left
ovary)
13,
11,
13,
13,
13,6
12,
6
14,
12,
7
6
13,7
5
7
10
13,9
12,
-
7
15,7
(Right
ovary)
Embryo
Corpora Albicantia No.
<2mm
6
0
4
0
0
4
7
12,5
14,
4
11,5
15,
13,
15,
14,7
15,
13,6
15,
15,
17,7
15,8
15,6
16,
14,3
0
0
0
0
0
0
0
0
0
2-4mm 4+mm
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
9
1
5
0
16
22
2
0
5
1
1
0
2
0
0
2
2
1
0
0
0
0
0
0
13
2
1
1
1
16
10
16
26
27
34
1
0
0
0
0
2-Smm 5-8mm
0
0
0
0
0
0
0
0
0
1
Follicle No.
0
0
1
0
0
0
0
1
0
1
0
1
0
1
1
0
0
1
1
0
1
1
0
1
2
0
0
0
1
1
1
0
1
22
19
18
20
17
1
2
1
3
2
6
2
28
4
2
8+mm
l(9mm)
R
0
0
R
61
0
6
18
L
M
22
6
R
114
24
L
101
L
R
R
M
M
2
105
16
10
30
24
58
103
144
0
0
0
0
1(8mm)
0
0
l(lOmm)
l(8mm)
l(lOmm)
0
0
0
0
1(8mm)
20
36
2
2
0
18
15
4
2
0
1
21
0
0
8
3
Sex
19
12
17
27
14
28
36
10
0
0
0
1
Total
Uterine CR/FR
horn
mm
1(8mm)
1(8mm)
l(lOmm)
0
24
22
L
L
R
L
R
L
-
19
L
23
19
8
L
31
5
22
38
20
17
R
R
-
R
L
L
35
15
19
30
139
114
28
82
26
47
66
5
L
22
28
L
11
R
26
Continued on next page
-
-
M
F
-
-
-
F
F2,
-
5
R
-
51
M
-
M
-
Table B continued.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Diameter in mm
Udder
(Ovarian Exam. Complete cont.)
68-337 11/16 5
Wet
67-279 12/8
6
Dry
68-329 11/19
6
Wet
68-290 11/17
7
Wet
67-181 11/16
8
67-271 12/31
8
Wet
68-230 11/16
8
Wet
68-331 11/16
8
Wet
67-186 11/16
9
68-327 11/16
9
Wet
68-335 11/16
9
Wet
(Ovarian Exam. Incomplete)
68-316 11/17
1
Dry
67-185 11/16
2
Wet
68-283 11/16
2
67-183 11/16
3
Dry
67-176 11/16
4
Wet
68-69
1/21
5
Wet
68-328 11/19
5
Wet
67-274 12/26
9
Wet
67-257
1/25 11-15
Wet
(Left
ova)
(Right
ovary)
15,
15,
7
7
14,
13,9
Embryo
Corpora Albicantia No.
<2mm
2-4mm 4+mm
0
1
1
1
0
1
1
0
0
0
0
-
-
-
-
0
0
-
1
0
0
0
0
1
0
-
-
-
1
1
0
0
0
0
-
-
-
11,6
7
15,
4
13,5
1
1
13,
11,
0
0
0
1
1
7
0
0
4
0
12,
15,
-
14, 7
-
-
-
13,6
-
2
0
1
-
-
4
-
2-5mm S-8mm
0
0
0
0
0
0
0
0
0
1
Follicle No.
!J(68_281) Embryo apparently alive, but lacking appendages; classified
as a teratism.
L'(68233) Embryo lost in field; chorion recovered from
uterus.
4
18
13
18
0
25
7
1
11
1
Total
0
1
1(8mm)
1(9mm)
2(9mm)
1
2
0
0
0
2
7
25
8+mm
l(8mm)
1
1
0
1
2
0
6
1
0
(right ovary only)
(ovaries cut off)
(right ovary only)
(
-
"
"
"
)
(left ovary only)
(embryo only collected)
(right ovary only)
(left ovary only)
(embryo only collected)
Uterine
horn
CR/FR
mm
Sex
5
L
32
-
20
16
20
27
L
114
F
R
R
R
28
-
83
M
8
L
12
9
26
L
L
3
L
179
4
72
89
12
7
R
61
L
16
L
15
25
45
R
L
L
-
-
35
22
228
95
196
208
-
M
-
M
F
-
-
-
M
F
M
F
Table C. Ovarian and uterine data--nonpregnant Rocky Mountain elk collected in Northeast Oregon, November 11-19, 1967.
Corpora Lutea
Collection
No.
Date
Age
(Years)
Diameter in mm
Udder
(Left
ovary)
(Right)
ovary)
Corpora Albicantia No.
<2mm
2-4mm
Follicle No.
2-5mm
4+mm
(Ovarian Exam. Complete)
67-217
-219
-187
-188
-218
-227
-171
-241
-169
-226
11/19
11/11
11/11
11/11
11/19
11/12
11/12
11/11
11/11
11/11
calf
calf
1
1
1
1
3
4
8
10
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Wet
Wet
13,
12,
Dry
Wet
13,
-
-
-
-
-
-
-
-
4r
5r
0
0
0
0
0
0
0
0
0
0
1
0
0
5-8mm
3
1
0
0
20
0
21
2
15
1
0
0
0
0
0
21
1
0
25
1
30
0
1
2
0
41
9
0
0
0
0
0
0
0
0
1
1
1
2
2
12
(Ovarian Exam. Incomplete)
-168
-190
11/13
11/11
1
3
-
0
0
*(67-190) Embryonic mortality suspected--uterus contained membrane fragments (1 mm
8+mm
Total
0
0
0
0
0
0
1(8mm)
0
1(8mm)
1b2mm)
(left ovary only)
(
"
"
"
)*
3 mm) that histologically resembled chorionic tissue.
4
20
23
16
22
25
32
42
12
15
Table D. Ovarian and uterine data--nonpregnant Rocky Mountain elk collected
in Northeast Oregon, November 16 and 17, and December 22, 1968.
Collection
No.
Date
Corpora Lutea
Age
(Years)
Udder
Diameter in mm
(Left
(Right
ovary)
ovary)
Corpora Albicantia No.
<2mm
(Ovarian Exam. Complete)
68-281
68-285
68-326
68-334
67-180
67-272
68-333
68-228
68-315
11/17
11/17
11/17
11/17
11/16
12/22
11/16
11/16
11/16
1
1
1
1
2
3
3
4
4
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Wet
Wet
4r
0
-
Sr
6r
11.
14,
16,
-
-
13,
0
0
11/16
11/16
1
10
Dry
Wet
8r
0
0
0
4+rnm
0
5-8mm
1
1
9
0
1(lOmm)'
2
1
1
1
0
0
1
0
0
1
1
1
1
1
3
1
1
1
(ovaries cut off)
0
Total
1
1
2
8+mm
0
0
0
1(8mm)
1(9mm)
0
0
0
0
2-5mm
26
19
12
23
17
25
19
24
10
0
0
0
0
(Ovarian Exam. Incomplete)
68-338
67-179
2-4mm
Follicle No.
0
0
0
0
27
20
13
24
20
26
26
12
2/
'(68-333) Embryonic mortality--fragments of
disintegrating chorion (largest 7 mm x 18 mm) present in tips of uterine horns;
histological examination indicated necrotic tissue
structure; embryo not located.
"(67-179) Right ovary only.
I
Appendix Table 3. Sex of Roosevel.t and Rocky Mountain elk fetuses collected
in Oregon, 1965, 1967
and 1968 reproductive seasons *
Males
Females
Roosevelt elk
2.7
22.
Rocky Mountain elk
12
12
Total
Fetuses
Males per
100 Females
Percent Males
49
12.3
55
24
100
50
Sexed
*Sex determined only for fetuses with forehead-rump length of at least 65 mm.
Appendix T.abie 4. Data on physical condition for pregnant Roosevelt elk collected on Millicoma area, 1967 reproductive season.
Embryo
Collection
No.
686
4
7
17
22
23
25
30
45
5
14
32
13
29
34
36
44
24
37
8
26
Date
(1968)
1/6
1/7
1/6
1/13
1/14
1/14
1/14
1/20
1/28
1/6
1/7
1/21
1/7
1/20
1/21
1/21
1/27
1/14
1/27
1/6
1/20
Age
(Years)
2
3
3
4
4
4
4
4
4
5
5
5
6
6
6
6
6
8
8
9
10
CR/FR
Udder
(mm)
Sex
Wet
Dry
192
168
186
289
174
205
103
284
292
226
218
232
177
139
254
F
Dry
Dry
Wet
Wet
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Dry
Wet
M
F
M
M
M
M
M
F
F
M
F
M
F
F
261
335
M
272
202
194
236
M
F
Kidney
Fat
Index
27
95
127
43
32
33
61
80
57
64
111
43
85
63
52
49
104
32
Percent Fat
Metatarsal
Marrow
(Wet Basis)
(Pounds)
Whole
79
89
87
90
89
90
89
89
88
74
480
526
526
596
623
546
578
576
577
658
91
69&
89
88
88
90
89
88
86
M
14
69
82
F
27
81
F
Body Weights
33
633
644
606
612
572
619
626
569
647
614
Hog-dressed
324
354
365
428
418
366
402
404
409
428
462
420
432
415
417
405
425
401
366
435
379
Total
Weight of
Adrenals
(gL
6.70
4.97
4.35
5.23
6.01
5.66
5.08
6.08
4.85
4.60
5.41
6.43
6.27
6.26
5.67
4.92
6.33
6.12
6.91
7.33
8.01
cg Adrenal per
lb Hog-dressed
Body Weight
2.07
140
1.19
1.22
1.44
1.,5
L26
1.50
1.19
1.07
L17
1.53
1.45
1.51
1.36
1.21
1.49
1.53
1.89
1.69
2.11
Appendix Table 5. Data on physical condition for nonpregnant Roosevelt elk collected on Millicorna area, 1967 reproductive season.
Collection
No.
Date
68-
(1968)
57
2/25
1/28
43
2
18
40
1
10
21
27
33
35
3
41
9
15
28
11
12
19
31
42
58
38
1/3
1/13
1/27
1/3
1/7
1/14
1/20
1/21
1/21
1/6
1/27
1/6
1/7
1/21
1/7
1/13
1/19
1/20
1/27
2/25
1/28
Age
(Years)
1
2
3
3
3
4
4
4
5
5
5
6
6
7
7
7
8
8
9
9
11-15
11-15
15+
Udder
Dry
Dry
Dry
Dry
Wet
Dry
Dry
Wet
Dry
Dry
Dry
Wet
Wet
Wet
Wet
Wet
Dry
Wet
Wet
Wet
Wet
Dry
Dry
Corpus
Luteum
Present
(x)
Kidney
Fat
Index
16
60
30
31
x
13
30
32
40
67
x
23
50
18
7
12
14
10
32
9
5
20
15
6
16
Percent Fat
Metatarsal
Marrow
(Wet Basis)
70
91
84
86
38
89
88
82
90
90
90
68
57
46
Body Weights
(Pounds)
Whole
432
495
537
524
529
628
614
586
582
586
602
591
596
600
11
601
65
67
351
367
395
356
-
43
88
20
12
Hog-dressed
658
562
577
446
390
408
415
408
371
360
408
408
394
444
371
581
376
356
378
519
316
568
1
21
Total
Weight of
Adrenals
(g)
3.61
5.62
4.42
4.24
5.73
5.30
5.24
6.64
3.98
4.72
5.86
5.65
6.79
5.54
6.31
5.59
6.98
6.06
7.64
6.61
6.20
6.17
cg Adrenal per
lb Hog-dressed
Body Weight
1.03
1.53
1.12
1.19
1.19
1.34
1.63
0.96
.1.15
1.58
1.57
1.66
1.36
1.60
1.26
,l.88
1.61
2.15
1.75
1.95
Appendix Tab].e 6. Data on physical condition for pregnant Roosevelt elk collected in Western Oregon, 1968 reproductive season.
Collection
Area
68-
No.
C
148
B
85
98
133
B
C
B
163
79
87
B
91
B
89
97
112
A
B
B
B
C
B
C
A
B
B
B
B
B
C
C
C
B
121
125
136
172
94
96
102
105
107
134
135
151
84
B
99
100
B
101
B
B
104
Embryo
Date
(1968)
12/14
11/3
11/8
12/7
11/17
11/2
11/3
11/3
11/3
11/7
11/10
11/17
12/14
12/7
11/17
11/5
11/6
11/9
11/9
11/9
12/7
12/7
12/15
11/3
11/8
11/9
11/9
11/9
Age
(Years)
1
2
2
2
2
3
3
3
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
6
6
6
6
6
CR/FR
Udder
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Dry
Dry
Dry
Dry
Dry
Wet
Dry
Dry
Wet
Dry
Dry
Wet
Wet
Dry
Wet
Dry
Dry
(mm)
72
30
Sex
F
-
35
83
M
3
5
-
50
54
102
15
M
11
Kidney
Fat
Index
96
101
198
175
156
137
256
266
163
100
36
75
133
M
M
114
115
F
137
164
102
27
4
13
55
-
-
50
6
4
107
120
15
24
69
74
70
-
M
F
M
M
F
65
48
232
187
62
165
228
44
80
141
63
284
218
Percent Fat
Metatarsal
Marrow
(Wet Basis)
89
88
91
89
-
Body Weight
(Pounds)
Whole
503
543
Hog-dressed
360
391
(g)
cg Adrenal per
lb Hog-dressed
Body Weight
4.00
1.11
1.08
3.82
6.00
5.65
4.07
5.22
5.01
0.98
4.21
-
-
-
90
89
90
90
527
586
600
552
388
413
91
661
491
455
334
86
89
89
87
Weight of
Adrenals
427
429
1.45
1.32
0.95
1.15
1.50
-
593
364
3.81
1.05
591
563
421
5.37
4.82
1.28
1.21
1.32
1.20
1.40
91
91
88
91
90
91
89
88
89
90
91
92
91
90
601
581
397
492
420
410
-
-
674
6.51
5.04
5.72
-
652
675
455
490
599
411
435
605
630
455
5.73
1.26
1.31
6.17
1.50
4.70
1.08
5.90
1.30
Continued on next page
6.41
Appendix Table 6 Continued.
Collection
Area
68B
A
B
B
B
B
C
No.
116
209
82
88
92
115
127
B
75
B
77
B
95
B
106
73
126
B
B
Embryo
Date
(1968)
11/10
11/16
11/3
11/3
11/4
11/10
12/7
11/2
11/2
11/6
11/9
11/2
12/14
Age
(Years)
6
6
7
7
7
7
7
8
8
8
8
9
9
CR/FR
Udder
(mm)
Wet
Wet
Wet
88
Dry
13
Wet
Dry
Wet
Wet
Dry
Wet
Dry
Wet
Dry
A = North Coast area.
B
Millicoma area
C Loon Lake area
VEmbryo not measured.
'Chorion fragmented; embryo not located.
Sex
M
-
15
101
50
53
33
82
39
44
M
-
M
-
-
Kidney
Fat
Index
148
122
73
190
100
180
50
61
175
32
194
73
48
Percent Fat
Metatarsal
Marrow
(Wet Basis)
Body Weight
(Pounds)
___________________
Whole
Hog-dressed
Total
Weight of
Adrenals
(g)
88
90
521
375
-
-
91
595
639
646
405
4.96
4.88
5.74
4.43
477
440
397
435
495
424
4.58
6.62
88
92
89
88
90
92
88
90
91.
90
671
439
435
499
5.06
729
643
lb Hog-dressed
Body Weight
1.35
-
-
631
619
591
631
cg Adrenal per
5.90
5.62
5.93
7.20
1.22
(.11
1.32
0.89
-
0.96
1.50
1.49
1.29
1.20
1.70
Appendix Table 7. Data on iihysical condition for nonpregnant Roosevelt elk collected in Western Oregon, 1968 reproductive
season.
Collection
Percent Fat
Body Weights
Total
Ovarian!
Kidney
Metatarsal
Weight
of
cg Adrenal per
(Pounds)
Area
Date
Age
Uterine
Fat
Marrow
Adrenals
lb Hog-dressed
68No.
(1968)
(Years)
Udder
Data
Index
(Wet Basis) Whole
Hog-dressed
(g)
Body Weight
B
76
83
103
B
111
B
B
C
A
A
B
149
207
210
74
B
78
B
B
A
B
B
B
B
B
C
A
86
110
174
80
108
109
118
120
152
B
181
81
B
90
B
93
B
C
C
B
B
B
117
137
150
72
114
113
11/2
11/3
11/9
11/10
12/15
11/16
11/17
11/2
11/2
11/4
11/10
11/16
11/2
11/9
11/10
11/10
11/16
12/15
11/16
11/2
11/3
11/5
11/10
12/8
12/15
11/2
11/10
11/10
1
1
1
1
1
1
1
2
2
2
2
2
3
4
4
4
4
4
4
5
5
5
5
6
7
8
8
9
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Dry
Wet
Wet
Wet
Wet
Wet
Wet
Wet
Wet
Dry
Wet
Dry
Wet
Wet
Wet
Dry
Wet
60
123
49
35
19
94
V
66
119
73
115
104
140
13
28
22
/,3j
V
V
V
64
47
37
56
30
50
33
V
59
/
14
92
209
V
25
21
89
90
87
86
88
443
481
465
453
-
-
-
-
-
90
90
90
88
36
89
89
88
85
549
535
539
561
319
344
319
311
4.76
3.77
4.19
3.86
1.31
1.24
-
380
389
379
392
4.97
4.71
3.81
3.31
1.31
1.21
1.01
0.84
-
561
571
551
586
601
87
385
399
389
393
420
5.29
4.05
5.14
4.51
5.97
1.37
1.02
1.32
1.15
1.42
-
85
87
88
89
86
76
42
90
89
79
1.49
1.10
663
519
611
571
473
354
447
418
6.60
6.63
6.55
5.30
1.40
.87
.47
1.20
5.49
1.26
-
653
644
546
437
483
352
1.14
5.51
6.35
1.80
Continued on next page
Appendix Table 7 Continued.
Collection
Area
68B
B
C
Date
No.
(1968)
Age
(Years)
123
124
132
11/23
12/14
12/7
11-15
11-15
11-15
North Coast area
B = Millicosna area
C = Loon Lale area
A
'Corpus luteuin present.
'Uterus containing nonviable chorion.
Ovaries containing cystic follicles.
Udder
Wet
Wet
Wet
Ovarian/
Uterine
Data
Kidney
Fat
Index
12
J, J
23
7
Percent Fat
Metatarsal
Marrow
(Wet Basis)
14
77
57
Body Weights
OUnd Si
Whole
551
605
-
Hog-dressed
417
377
Total
Weight of
Adrenals
(g)
6.68
4.70
cg Adrenal per
lb Hog-dressed
Body Weight
1.60
1.27