Reproductive Physiology of
Beef and Cattle
Suporn Katawatin
Department of Animal Science
Khon Kaen University
 Reproduction is one of the most
important consideration determining the
profit of cattle production
RECORD
NUTRITION
ESTROUS DETECTION
MANAGEMENT
HERD
HEALTH
DAYS OPEN
FEMALE
(85 days)
FERTILITY
CONTROL GENITAL DISEASE
ARTIFICIAL
PREGNANCY DIAGNOSIS
INSEMINATION
REDUCE AGE AT 1ST CALVING
INCREASE % COWS CYCLING
TREAT PROBLEM COWS
IMPROVE AI TECHNIQUE
USE GOOD QUALITY SEMEN
BREED COWS IN STANDING HEAT
 Good reproduction is …
to show regular cyclic breeding
activity
Reproductive Physiology
 Male and Female Reproductive Anatomy
 Puberty : age or body weight
 Sexual maturity
 Estrous Cycle
 Mating or Breeding
 Calving
 Lactation
 Recycling
Female Reproductive
Characteristics of Cattle and Buffalo
Parameters
Cattle
Buffalo
Age at puberty (mth)
15 (10-24)
21 (15-36)
Estrous cycle
Length (d)
Estrus (h)
21 (14-29)
18 (12-30)
21 (18-22)
21 (17-24)
Ovulation
Type
Time from onset (h)
Spontaneous
30 (18-48)
Spontaneous
32 (18-45)
Female Reproductive
Characteristics of Cattle and Buffalo
Parameter
Life span of CL (d)
Fertilizable life of ova (h)
Entry of ova into uterus
(h after ovulation)
Gestation length (d)
Cattle
Buffalo
16
16
(20 – 24)
??
90 (64-96)
??
280 (278-293) 315 (305-330)
Female Reproductive
Characteristics of Cattle and Buffalo
Parameter
Cattle
Buffalo
Age at 1st calving (months)
30 (24-36)
42 (36-56)
Postpartum interval (days)
Uterine involution
First ovulation
Calving interval (months)
45 (32-50) 35 (16-60)
30 (10-110) 75 (35-180)
13 (12-14)
18 (15-21)
Areas of controlled reproduction in female cattle
Control estrus
Suppression
of estrus
Breeding cattle at
younger ages
Induction of
twin births
Controlled
reproduction
in cattle
Pregnancy
testing
Control
calving
Embryo transfer
& in vitro
fertilization
Control postpartum
interval
Heat Detection
or Estrous Detection
 Estrous behavior
Before heat (6-10 h)
Smells other cows
Attempts to ride other cows
Vulva moist, red slightly swollen
Standing heat (18 h)
Stand to be ridden
Bawls frequently
Nervous & excitable
Off feed and milk
Vulva moist and red
Clear mucous discharge
Eye pupil dilated
After heat (10 h)
Will not stand
Clear mucous discharge from vulva
Hours from the start of estrus
Hours 0
Before heat
(6-10 h)
6
9
Standing
heat (18 h)
18
24
28
Egg released
After heat
(10 h)
Life of egg
(6-10 h)
Estrus in cow and associated featured
Approaches to estrus detection in the cow
Tail-painting & use of
chalk
Heat-mount
detectors
Use of closed
circuit television
Cow activity
changes
Progesterone
tests
Techniques
used in
estrous
detection
Vaginal probes
Chin-ball
devices
Use of
teaser
animals
Hormonal Pattern During
Estrous Cycle in Cow
Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Gonadotropins
Method
Biologic Activity
eCG or PMSG
Single injection
Mimics FSH and
stimulates follicular
growth; long halflife
FSH
Single/multiple
injections
Stimulates follicular
growth; short halflife
hCG
Single injection
Mimics LH and
induce ovulation
Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method
Biologic Activity
Single
injection
Induces release of
LH and FSH from
the anterior
pituitary gland;
recruitment and
selection of new
dominant follicle
Gonadotropin Releasing
Hormone Agonist
GnRH-buselerin
Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method
Biologic Activity
Progestogens
Progesterone
Synthetic
progestogens
Multiple injections Inhibits ovulation by
suppressing LH;
mimics action of CL
Oral,
subcutaneous
implant,
intravaginal
device
Inhibits ovulation by
suppressing LH;
mimics action of CL
Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Estrogens
Estradiol
conjugates
Prostaglandins
PGF2 or
synthetic
analogs
Method of
Administration
Biologic Activity
Injection, implant
Induce premature regression
of CL, and enhances
response to progestrogens
Single
intramuscular
injection
Induces regression of CL
during responsive phases
Protocols for Inducing Estrus and Ovulation in
Acyclic Cattle and Buffalo
Prepubertal or
postpartum
suckled cows
Treatment
End of Treatment
to Estrus
Estrogen on day 1
followed by 7 -12 days of
progesterogen, eCG given
on last day (optional)
Within 5 days
Postpartum milked GnRH on day 14
postpartum
cows
GnRH (day 0) and PGF
(day 6)
1 day
2-4 days
Techniques for Synchronizing Estrus
in Cyclic Cattle
Method
Treatment Regimen
End of treatment to
estrus
3-5 days: AIDE/TAI
PGF
Two injections
(11-12 days apart)
GnRH + PGF
Inject GnRH (day 0), PGF
(day 6)
2-4 days: TAI
GnRH + PGF +
GnRH
Inject GnRH (day 0), PGF
(day 7), GnRH (day 8 or 9)
2-4 days: TAI
Techniques for Synchronizing Estrus in Cyclic
Cattle.
Treatment Regimen
End of
treatment to
estrus
Progestogen +
estrogen
Estrogen injection (day
1), CIDR (day 1-9X
3-5 days : AIDE/TAI
Progestogen
+PGF
Progestogen (days1-7),
PGF (day 6)
2-3 days:
AIDE/TAI
Method
OVSync
PGF2
GnRH
(100ug)
(35mg)
7 days
Ovulate follicle
Start new follicle
wave
GnRH
(100ug)
48 h
Regress
corpora lutea
Breed
(cows)
24 h
Ovulate
follicle
Timing and purpose of hormones to synchronize
ovulation in lactating dairy cow (Pursley et al.,
1995)
Measure Reproductive Efficiency
Trait
Definition
First calving
Age (months)
Days open
Days calving to conception
Calving interval (days) Days between successive calving
Total cows
First service
No. pregnant 1st service X 100
conception rate (%)
No. bred 1st service
Measure Reproductive Efficiency
Trait
Services per conception
Pregnancy rate (%)
Calving rate (%)
Net calf crop (%)
Definition
No. of services in all cows
Total conceptions
No. of cows pregnant X 100
Total cows in herd
No. of calves born
X 100
Total cows in herd
Total calves weaned X 100
Total cows in herd
Book Suggestion
 Hafez, E.S.E. and B. Hafez. 2000. Reproduction in
Farm Animals. 7th ed. Lippincott Williams &
Wilkins, New York.
 Gordon, I. 1996. Controlled Reproduction
in Cattle & Buffaloes. CAB International.
 Bearden, H.J. and J.W. Fuquay. 1997. Applied Animal
Reproduction 4th ed. Prentice Hall.
Approximate Values for Selected Reproductive Events in Female Domesticated Mammals
Specie
s
Length of
cycle
(days)
Duration of
estrus
(hours)
Approximate time of
ovulation
Normal breeding
season
Cow
Mean=20.5
Range 17 23
Mean < 10
Range 1 - 24
30 h after beginning of
estrus
All year
Buffal
o
Mean=21
Range 18 22
Mean < 15
Range 4 - 24
32 h after beginning of
estrus
All year
Mean=21
Range 12 35
Mean=120
Range 24 240
Near end of estrus
Spring & summer
Mare
Ewe
Mean=16
Range 12 19
Mean=30
Range 20 -48
26 h after beginning of
estrus
Fall (variable with
breed)
Doe
Mean=20
Range 16 22
Mean=40
Range 24 72
On 2nd day of estrus
Fall
Mean=20
Range 16 22
Mean=48
Range 24 90
36 h after beginning of
estrus
All year
Sow