ARIZONA AND NEW MEXICO
DAIRY NEWSLETTER
COOPERATIVE EXTENSION
The University of Arizona
New Mexico State University
JUNE 2006
THIS MONTH’S ARTICLE:
Managing the Heat-Stressed
Cow to Improve Reproduction
Peter J. Hansen
Department of Animal Sciences
University of Florida, Gainesville Florida
(Reprinted from the Proceedings of the 7th Western Dairy Management Conference,
March 9-11, 2005, Reno, NV)
Managing the Heat-Stressed Cow to Improve Reproduction
Peter J. Hansen
Department of Animal Sciences
University of Florida, Gainesville Florida 32611-0910
Ph: 352-392-5590 Fax: 352-392-5595
The Growing Problem of Heat Stress
A high-producing cow starts to experience an increase in body temperature at air temperatures as low
as 80°F. As a result, heat stress is a problem throughout most of the country, even in places as far north
as Wisconsin. Cows that are exposed to heat stress suffer decreased feed intake, reduced milk yield,
poor expression of the signs of estrus, and infertility.
Cows experience an increase in body temperature in hot weather because they cannot lose all of the
body heat they produce to the environment. High-producing cows produce more heat than lowproducing ones and, therefore, the effects of heat stress increases as milk yield increases. This idea is
illustrated in Figure 1 which depicts seasonal variation in 90–day non-return rate (an estimate of
conception rate) for cows in Florida and South Georgia. Note that the summer-depression in fertility is
greater, and lasts for more months, for cows producing between >20,000 lb of milk per lactation than
for cows producing less between 10,000-20,000 lb of milk. The summer depression in fertility is small
for cows producing less than 10,000 lb of milk.
What this means is that as we continue to increase milk yield (by genetic selection, improved feeding
practices, etc.), we will be making cow more susceptible to heat stress. Much has been made of the
fact that the dairy cow is less fertile today than is was 20 or 30 years ago. At least part of this decline is
because cows are more susceptible to heat stress than they were before. Reducing the impact of heat
stress on reproduction is one way to reverse some of this historical decline in dairy cow fertility.
Going Beyond Cooling the Cow
In places like Florida and Arizona, where heat stress is a continual and severe problem, the most
common approach that dairy farmers have taken to minimize effects of heat stress has been to modify
housing to cool the cow. The optimal use of such modifications of dairy cow housing as shade,
sprinklers, fans, and misters is beyond the scope of this paper. Three points are relevant, however.
First, cooling cows can be an important way to reduce effects of heat stress on milk yield and
reproduction and should be incorporated into dairy housing systems when feasible. Second, there is
ongoing research into use of new cooling methods such as tunnel ventilation that may prove more
effective than existing systems that focus on fans in combination with sprinklers and sprayers. Finally,
cooling systems do not usually eliminate the seasonal depression in fertility, at least in places like Florida
where heat stress can be severe. The last point is illustrated by data in Figure 2 that show monthly
Proceedings of the 7 th Western Dairy Management Conference w March 9-11, 2005 w Reno, NV w
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variation in conception rates for a 2000-head unit in South Florida in which cows were housed in
freestalls with sprinklers and fans. Note that the use of these cooling aids did not prevent a large
decline in conception rates during the summer.
The inability of current cooling systems to eliminate the summer depression in reproduction means that it
is useful to have other approaches for improving reproduction during heat stress. This paper will focus on
approaches for improving reproduction in the summer that are based on overcoming changes in the cow’s
physiology that are disrupted by heat stress.
Aspects of Reproduction Disrupted by Heat Stress
Simply put, it is difficult to get cows pregnant during heat stress because 1) it is hard to see cows in heat
and 2) even if heat is detected, few cows conceive after insemination.
Detection of estrus is not easy even in the absence of heat stress. Using the HeatWatch® patches to
record each time a cow is mounted, researchers at Virginia Tech University have estimated that estrus
in the lactating dairy lasts only 7-10 hours. During that time, cows are mounted an average of 8-10
times. The total amount of time spent being mounted (calculated as the number of mounts times the
amount of time being ridden) is only about 24 seconds. Compounding the problem is the fact that estrus
gets shorter in length as milk yield goes up. An important point to consider is that cows that show a
weak estrus (in other words, don’t get mounted many times or exhibit estrus for very long) are just as
fertile as cows that are very active sexually during estrus (see Table 1). Thus, failure to identify cows
with poor symptoms of estrus has just as much effects on the subsequent herd conception rate as failure
to identify a cow with very intense sexual behavior.
Table 1. Effect of intensity of estrus on conception rates in lactating cows.1
Category of estrus 2
Percent of cows in that category
Conception rate (%)
Low intensity-short duration
24.1
45.6
Low intensity-long duration
33.2
45.5
High intensity-short duration
34.3
47.0
High intensity-long duration
8.4
1 From Dransfield et al., J. Dairy Sci. 81, 1874-1882 (1998)
49.8
Given this cow behavior, it is not surprising that so many heats are not detected. In a study in Florida,
for example, over 40% of the estrus periodss were missed in the best months (Figure 3). In the worst
months, those associated with heat stress, 75-80% of the estrus periods were missed. The difficulty in
detecting estrus in the summer is because heat stress reduces both the length of time that a cow is in
estrus as well as the number of mounts.
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The other major effect of heat stress on reproduction is a reduction in the proportion of cows that
become pregnant after insemination. This effect has already been illustrated in Figures 1 and 2. The
magnitude of the summer depression in fertility can be large - conception rates of 10% or less are
common during the summer in Florida.
There are multiple causes for the poor fertility during heat stress. One action of heat stress is to disrupt
the function of the follicle - the structure where development of the egg (or oocyte) takes place. As a
result, heat-stressed cows tend to produce oocytes that have reduced capability of becoming fertilized
and, if fertilization does take place, of becoming embryos capable of normal development. Cows
exposed to heat stress typically have elevated body temperatures that are high enough to damage the
oocyte directly and also to kill the embryo. Finally, the blood levels of the hormone progesterone,
which is responsible for maintaining pregnancy, can be reduced in heat stressed cows.
How Hot is Too Hot?
In a place like Florida, it is not too difficult to determine when the weather is likely to cause the cow to
be heat stressed. Almost every day in the summer is hot enough to compromise reproduction and
decrease milk yield. In other environments, it is less obvious whether the weather is hot enough to
affect the cow adversely. Accordingly, a variety of indices have been developed to help predict
whether cows are under heat stress. The most common of these is the temperature-humidity index
which is calculated from the air temperature and relative humidity. These indices only provide a rough
indication as to whether the cow is heat stressed. That is so because a cow’s body temperature
depends on other environmental variables in addition to air temperature and humidity, especially wind
speed and solar radiation. In addition, cow factors determine the magnitude of the increase in body
temperature experienced during heat stress. High-producing cows tend to be more affected by heat
stress than low-producing cows, black cows are more sensitive than white cows, and BST can increase
susceptibility to heat stress.
The best way to determine how badly cows are being affected by heat stress is to measure the rectal
temperature. Normal body temperature of the cow is about 101.3°F. It has been shown that an
increase in body temperature of about 0.9°F causes a decline in conception rate of 12.8%
[Gwazdauskas et al., J. Dairy Sci. 56, 873-877 (1973)]. One can consider that a cow that has a
rectal temperature of about 102.2°F or higher in the afternoon is likely to be heat stressed (if she does
not have mastitis or is otherwise sick). Determining rectal temperatures on groups of cows in the
afternoon can be a quick way to get an accurate assessment of the degree of heat stress and the
effectiveness of any cooling systems incorporated into cow housing.
Minimizing the Impact of Heat Stress on Detection of Estrus
Fortunately, there are several techniques available for overcoming the effect of heat stress on detection
of estrus. One approach is to incorporate one of the many estrus detection aids available. The simplest
Proceedings of the 7 th Western Dairy Management Conference w March 9-11, 2005 w Reno, NV w
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of these is chalk applied to the tailhead. Rubbed-off chalk indicates the cow was in estrus. The
effectiveness of chalking the tail was demonstrated in an experiment conducted in the summer in South
Florida with lactating cows. The percentage of cows detected in estrus after estrous synchronization
using Lutalyse® was 26% based on visual detection only versus 43% based on visual detection was
combined with tail chalk [Ealy et al., J. Dairy Sci. 77, 3601-3607 (1994)].
A variety of tailhead patches for detection of mounts are also sold . These include the KaMar®,
Bovine Beacon® and Estrus AlertTM patches. The HeatWatch® system is the most sophisticated
device to measure mounting behavior. It consists of a pressure transducer applied to the tailhead inside
a large glued-on patch. Each time the cow is mounted, information is sent to a computer recording the
time and duration of the mount. This system is the gold standard for estrus detection but is also very
expensive. Cows that wear the HeatWatch patch for a prolonged time can experience tissue irritation
and damage underneath the patch.
Other remote systems for estrus detection use pedometers to measure the number of steps cows take.
These devices are based on the fact that cows in estrus spend more time walking than other cows.
There is still a shortage of data regarding how well these systems work in facilitating estrus detection.
Development of timed artificial insemination protocols such as the OvSynch procedure make it possible
to avoid the need for estrus detection and inseminate cows at a fixed time. Use of OvSynch in heat
stressed cows has been shown to increase the rate at which cows get pregnant after calving. In a
Florida herd with a voluntary waiting period of 70 days, the percentage of cows that were pregnant by
90 days postpartum was 16.6% for cows in which first insemination was via timed artificial insemination
using OvSynch vs 9.8% for cows bred based on visual estrus detection only [Aréchiga et al., J. Dairy
Sci. 81, 390-402 (1998)].
In a Kansas study [Cartmill et al., J. Dairy Sci. 84, 799-806 (2001)], cows in the summer were
inseminated between 50 and 70 days in milk using one of two breeding protocols. One group was
timed inseminated following the OvSynch protocol. The other group was inseminated after a detected
estrus induced by an estrous synchronization protocol (GnRH followed 7 days later by Lutalyse). All
of the OvSynch cows were inseminated vs 58.7% of cows subjected to estrous synchronization. There
was no difference in conception rate between the two groups (33.3% for OvSynch vs 32.0% for
estrous synchronization) but because more cows were inseminated, the proportion of cows pregnant
using ultrasound diagnosis at day27-30 of gestation was greater for the OvSynch group (33.3% vs
16.7%). In this study, the pregnancy loss after day 27-30 was greater for the OvSynch group so overall
pregnancy rates at day 40-50 were similar between the two groups (16.4% for OvSynch vs 13.3% for
estrous synchronization).
Is it economical to use timed artificial insemination during heat stress? This is an important question
because timed artificial insemination works by increasing the number of cows inseminated and not by
reducing the effects of heat stress on fertility. Semen and drug costs are incurred for all cows
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subjected to timed artificial insemination and the fact that cows are heat stressed means that only a small
fraction of cows will become pregnant. There has not been a detailed economic analysis of the benefits
of timed artificial insemination during heat stress. However, it makes sense that timed artificial
insemination is more valuable on farms where estrus detection is poor.
Improving Fertility in Cows Subjected to Artificial Insemination
If we could find a way to increase the conception rate of heat-stressed cows, timed artificial
insemination would be a very practical system during the summer. In fact, however, the only known
method for increasing fertility in heat-stressed cows is to cool the cow. A wide variety of hormonal
treatments have been tested for increasing fertility of heat-stressed cows but none of them have been
shown to consistently cause an increase in fertility of heat-stressed cows. Until such a treatment is
developed, it will be difficult to achieve optimal conception rates following artificial insemination in heatstressed cows.
Can Using a Bull Help?
The proportion of cows inseminated artificially in the United States declines during the summer months.
In part, this may reflect unwillingness to use semen (which is relatively expensive) during times of the
year when fertility is low. There is also interest in bull breeding to help solve reproduction problems.
One obvious advantage to using bulls during heat stress is that bulls are better at detection of estrus than
humans. Keep in mind, though, that the bull is susceptible to heat stress just like the cow. The bull
probably does not get as hot as the lactating cow because its metabolism is lower. However, when heat
stress gets severe enough, it can cause decreased libido in the bull and a decline in semen quality that
persists for about two months after the end of heat stress. The lag in restoration of fertility after heat
stress is the result of damage to the precursor cells for spermatozoa. There are no experimental data
regarding whether use of bulls actually increases the proportion of cows that get pregnant during heat
stress. It makes sense, though, that the benefits of the bull will be limited when heat stress is severe
enough to affect the bull’s body temperature.
Embryo Transfer as a Tool to Improve Pregnancy Rate
Earlier, it was mentioned that one of the causes of infertility in the summer is the lethal effects of
elevated body temperature on the oocyte and embryo. One of the features of embryonic development
is that embryos become more resistant to various stresses as they become older. Thus, heat stress on
the day after breeding can block embryos from developing while heat stress at seven days after
breeding has little effect on embryonic survival. The use of embryo transfer to improve fertility in the
summer is based on the fact that embryos are typically transferred into the uterus of recipient cows at
day 7-8 after estrus, a time when the embryo has already passed the period when it is most susceptible
to elevated temperature (see Figure 4). Effects of heat stress on the oocyte are avoided because the
only embryos transferred are those derived from oocytes with sufficient quality to give rise to
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transferable embryos. Embryos can also be produced during cool months of the year, when the oocyte
is not susceptible to heat damage, and then frozen until transfer in the summer.
Pregnancy rates in lactating cows exposed to heat stress can be improved as compared to artificial
insemination. The source of embryo, though, has a major effect on the success rate. The best embryos
that can be transferred in terms of chances of establishing pregnancies are embryos produced by
superovulation. In this procedure, donor cows are treated with multiple injections of follicle-stimulating
hormone to cause growth and ovulation of multiple follicles. As shown in Figure 5, transfer of fresh
(i.e., non-frozen) embryos from superovulated cows into heat-stressed recipients improved pregnancy
rates from 13.5% for artificial insemination to 29.2% for embryo transfer. An increase in pregnancy
rate using superovulated embryos is also seen when superovulated embryos are transferred after longterm storage by freezing. In particular, it was found that pregnancy rate for artificial insemination was
24.1% vs 35.4% for cows receiving a frozen-thawed superovulated embryo.
Embryo Transfer Using Embryos Produced In Vitro
Superovulation is a time consuming and expensive procedure. Generally, 4-8 transferrable embryos
are produced per superovulation procedure at a cost of about $75-125 per embryo. Donor cows can
be used no more frequently than once a month and, more commonly, less often. Another method for
producing embryos is through in vitro fertilization (IVF). In this procedure, oocytes recovered from
donor cows are fertilized in the laboratory. Oocytes can be recovered from living donors using a
procedure called transvaginal, ultrasound-guided, oocyte recovery (or oocyte pickup or OPU for
short). One advantage of OPU over superovulation is that the procedure can be produced as often as
twice weekly and can be performed on pregnant cows as well as open cows. Oocyte pickup is an
expensive procedure, however. A typical fee for a single collection (yielding 1-2 transferrable
embryos) is $400. Moreover, OPU requires highly skilled personnel and specialized equipment.
OPU is best used when the goal is to obtain offspring from valuable donor cows.
An alternative IVF procedure is to harvest oocytes from ovaries collected at a slaughterhouse. While
the identity of the donor animal is not known, the cost of producing embryos from slaughterhouse
oocytes is relatively cheap. Estimates for commercial production of embryos using slaughterhouse
oocytes is about $15 to $30 per embryo. Among the companies that will produce embryos using
slaughterhouse oocytes are BOMED (Madison, WI) and Transova (Sioux Center, Iowa)
The genetic value of embryos produced by slaughterhouse embryos can be high. It has been shown
that the predicted transmitting ability for milk yield for cows sent to slaughter is only slightly less than the
overall population of cows. Moreover, since one straw of semen can be used in IVF to produce
dozens of embryos, embryos of high genetic potential can be produced inexpensively. When sexed
semen comes on the market, its use can be incorporated into IVF systems to produce large numbers of
female embryos inexpensively.
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Like for superovulated embryos, pregnancy rates in the summer can be improved by transferring
embryos produced in vitro to cows (see Figure 4). However, in vitro produced embryos do not
survive freezing as well as embryos produced by superovulation and the increase in pregnancy rate
achieved by transfer of embryos produced in vitro is only seen when fresh embryos are transferred
(Figures 3-4). Pregnancy rates achieved following transfer of a frozen-thawed embryo produced in
vitro were no higher than what is achieved by AI.
Problems with Embryos Produced In Vitro
The inexpensive cost of embryos produced using slaughterhouse oocytes make them a compelling
choice for embryo transfer schemes whose primary purpose is to increase fertility during summer. It is
important to remember, however, that there are additional problems associated with the use of these
embryos. In addition to not freezing well, a high rate of fetal loss has been reported following transfer
of embryos produced in vitro. In our hands [Block et al., J. Anim. Sci. 81, 1590-1603 (2002)], 24%
of cows pregnant at day 53 of pregnancy lost their pregnancy before calving. This compares to a value
of about 10% for lactating cows bred via artificial insemination. There can also be a higher incidence of
prenatal mortality associated with calves produced by in vitro fertilization. Calves produced from in
vitro produced embryos also tend to be larger at birth - in our system, Holstein calves produced from in
vitro-produced embryos weighed an average of 94 lb at birth. Occasionally, very large calves (as
much as 200 lb) can be born. The occurrence of these grossly oversized calves is less frequent than
was previously the case because of changes in culture conditions (removal of serum from the growth
medium used to produce embryos).
In many culture systems used to produce embryos, a greater proportion of transferrable embryos are
male. In our last study [Block et al., J. Anim. Sci. 81, 1590-1603 (2002)], 64% of calves born from
embryo transfer using embryos produced in vitro were male. In the future, changes in culture conditions
should eliminate this problem. Indeed, sexed semen, which has now been developed and will one day
become commercially available, is ideally suited for IVF since one straw of semen can be used to
produce multiple embryos.
Embryo Transfer and Estrus Detection
Use of embryo transfer in the summer is made difficult by the fact that estrus detection is reduced during
heat stress. It is inefficient to place embryos into recipient cows at 7 or 8 days after estrus when estrus
is not observed in 50% or so of the cows. Fortunately, the same hormonal treatments that can be used
to synchronize ovulation for AI can also be used to synchronize ovulation for embryo transfer. In our
hands, we have transferred embryos into recipients in which ovulation was synchronized with the
GnRH-PGF-GnRH scheme used for OvSynch (with or without prostaglandin presynchronization).
Pregnancy rates achieved with timed embryo transfer are shown in Figure 4 and a typical timed embryo
transfer scheme is detailed in Table 1.
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Take Home Messages
Heat stress can be a difficult problem to manage. There are several things to keep in mind when trying
to mitigate its effect on reproduction. These include the following:
•
Keep cows as cool as possible by providing them with access to shade, forced air ventilation,
and some form of evaporative cooling such as sprinklers or misters.
•
Measure body temperatures in the afternoon in subsets of cows in each animal housing area to
see how good of a job you are doing at keeping cows cool and work to improve the situation
when body temperatures are often above 102.2°F.
•
Use tail chalk, KaMars or other devices to facilitate detection of estrus in the summer.
•
Consider the use of OvSynch in the summer to improve the number of cows submitted for
insemination. OvSynch is more likely to pay for itself when the estrus detection rate is very
low.
•
Be careful before making the decision to use natural breeding in the summer and make sure that
the bulls themselves won’t be adversely affected by heat stress.
•
Consider the use of embryo transfer as a reproductive management tool for getting cows
pregnant during heat stress.
Acknowledgements
Some of the research leading to the use of embryo transfer was supported by the Florida Dairy CheckOff Program and Grant No. 2001-52101-11318 from the USDA Initiative for Future Agricultural and
Food Systems.
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Figure 1. The effect of milk yield on seasonal variation in 90-day nonreturn rate in dairy cows in
Florida and South Georgia. The term 90-day nonreturn rate signifies the percentage of cows that were
not seen in estrus in the 90 days after insemination. The lines represent data for cows producing less
than 10,000 lb of milk per lactation (closed circles), 10,000-20,000 lb (open circles), and greater than
20,000 lb (closed triangles). Data are from Al-Katanani et al., J. Dairy Sci. 82, 2611-2615 (1999).
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Figure 2. Seasonal variation in pregnancy rate (number pregnant/number inseminated) on a
commercial dairy in Florida in which cows were housed in freestall barns with fans and sprinklers. Data
are from Hansen and Aréchiga, J. Anim. Sci. 77 (Suppl 2): 36-50 (1999).
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Figure 3. Seasonal variation in the estimated proportion of missed estruses in a Jersey herd in North
Florida. Data come from Thatcher and Collier (In D.A. Morrow, ed., Current Therapy in
Theriogenology 2, Philadelphia, WB Saunders, 1986).
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Figure 4. Illustration of the mechanism by which embryo transfer can be used to increased fertility in
heat-stressed cows. Before estrus, the oocyte growing within the follicle is very sensitive to disruption
by exposure of cows to heat stress. After estrus and ovulation, the oocyte and newly fertilized embryo
is also very sensitive to elevated temperature. As the embryo grows, it becomes more resistant to heat
stress. Transfer of an embryo into the uterus at day 7 after estrus thus bypasses effects of heat stress
on the oocyte and early embryo.
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Figure 5. Effectiveness of embryo transfer for improving pregnancy rates of lactating dairy cows during
heat stress. Experiments were conducted in Florida during the hot period of the year. Embryos were
transferred after collection (fresh) or after cryopreservation (frozen). Pregnancy was determined by
rectal palpation at 40-60 days of gestation. Abbreviations are AI=artificial insemination,
SO=superovulation, and IVF=embryo produced by in vitro fertilization. Numbers above each bar
represent percent pregnant and numbers in parentheses are the number of recipients. Data are from
Putney et al. [Theriogenology 31, 765-778 (1989)] and Drost et al. [Theriogenology 52,1161-1167
(1999)].
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Figure 6. Effectiveness of timed embryo transfer using embryos produced in vitro for improving
pregnancy rates of lactating dairy cows during heat stress. Experiments were conducted in Florida
during the hot period of the year. Ovulation was synchronized using the OvSynch procedure and cows
were either inseminated at a fixed time (timed AI; TAI) or received an embryo at a fixed time (timed
embryo transfer; TET). Embryos were either unfrozen (fresh), or were frozen by conventional
procedures (frozen) or by vitrification (vitrified). Pregnancy was determined by rectal palpation at
40-60 days of gestation. Numbers above each bar represent percent pregnant and numbers in
parentheses are the number of recipients. Data are from Ambrose et al. [J. Dairy Sci. 82, 2369-2376
(1999)] and Al-Katanani et al. [Theriogenology 58, 171-182 (2002)].
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HIGH COW REPORT
APRIL 2006
MILK
Arizona Owner
* Withrow Dairy
* Stotz Dairy
* Dairyland Milk Company
* Dairyland Milk Company
* Shamrock Farms
* Mike Pylman
* Goldman Dairy
* Stotz Dairy
* Mike Pylman
* Stotz Dairy
Barn#
4202
18842
7441
1418
U42
2433
4661
18729
959
17021
* Stotz Dairy
* Stotz Dairy
* Stotz Dairy
* Stotz Dairy
* Dutch View Dairy
* Mike Pylman
* Stotz Dairy
* Dairyland Milk Company
* Stotz Dairy
* Stotz Dairy
* Stotz Dairy
18836
18842
17372
20040
197
2081
20401
9334
18729
18757
20043
* Stotz Dairy
* Mike Pylman
* Mike Pylman
* Mike Pylman
* Withrow Dairy
* Mike Pylman
* Stotz Dairy
* Mike Pylman
* Goldman Dairy
* Stotz Dairy
* Dutch View Dairy
18842
893
959
757
4202
2081
20190
864
4661
20288
289
Age
06-03
03-05
07-01
05-03
07-06
04-01
01-09
03-06
03-00
04-10
Milk
35,920
35,350
35,040
34,330
34,240
33,830
33,740
33,710
33,650
33,560
New Mexico Owner
Barn #
Age
FAT
03-06
03-05
04-06
03-04
05-01
05-10
03-02
04-04
03-06
03-06
03-04
1,385
1,385
1,355
1,345
1,322
1,302
1,280
1,255
1,243
1,243
1,243
PROTEIN
03-05
03-01
03-00
03-02
06-03
05-10
03-02
02-11
01-09
03-02
04-01
*all or part of lactation is 3X or 4X milking
1,094
1,019
1,015
972
970
966
964
959
957
954
954
Information
unavailable at
press time.
Milk
ARIZONA - TOP 50% FOR F.C.M.b
APRIL 2006
OWNERS NAME
* Stotz Dairy West
* Stotz Dairy East
* Mike Pylman
* Joharra Dairy
* Del Rio Dairy, Inc.
* Red River Dairy
* Zimmerman Dairy
Paul Rovey Dairy
* Arizona Dairy Company
Parker Dairy
* Danzeisen Dairy, Inc.
* Dairyland Milk Co.
* Withrow Dairy
* Goldman Dairy
* RG Dairy, LLC
* Yettem
* Shamrock Farm
Lunts Dairy
* Dutch View Dairy
* Saddle Mountain
Number of Cows
2,217
1,017
7,987
1,400
1,373
5,181
1,190
144
5,564
4,201
1,417
2,978
5,302
2,194
1,246
2,740
8,419
584
1,749
3,039
MILK
28,273
24,973
25,554
25,487
24,717
24,746
24,264
23,954
23,909
23,010
23,283
23,377
24,180
23,072
22,379
19,024
23,286
21,133
21,066
21,368
FAT
1,017
905
888
872
871
864
860
857
816
837
824
818
789
794
784
866
751
774
748
717
3.5 FCM
28,711
25,468
25,444
25,156
24,807
24,706
24,432
24,250
23,566
23,517
23,425
23,368
23,245
22,847
22,385
22,264
22,243
21,684
21,234
20,862
RR
37
35
38
27
24
34
20
35
39
25
36
37
38
26
45
23
38
31
29
27
3.5 FCM
RR
NEW MEXICO - TOP 50% ACTUAL MILK
APRIL 2006
OWNERS NAME
Number of Cows
MILK
FAT
UNAVAILABLE AT PRESS TIME
* all or part of lactation is 3X or 4X milking
b
average milk and fat figure may be different from monthly herd summary; figures used are last day/month
ARIZONA AND NEW MEXICO HERD IMPROVEMENT SUMMARY
FOR OFFICIAL HERDS TESTED APRIL 2006
ARIZONA
1. Number of Herds
39
2. Total Cows in Herd
67,659
3. Average Herd Size
1,735
4. Percent in Milk
91
5. Average Days in Milk
211
6. Average Milk – All Cows Per Day
68.5
7. Average Percent Fat – All Cows
8. Total Cows in Milk
9. Average Daily Milk for Milking Cows
10. Average Days in Milk 1st Breeding
3.6
66,414
73.7
83
11. Average Days Open
164
12. Average Calving Interval
14.2
13. Percent Somatic Cell – Low
NEW MEXICO
UNAVAILABLE
AT PRESS
TIME
87
14. Percent Somatic Cell – Medium
8
15. Percent Somatic Cell – High
5
16. Average Previous Days Dry
60
17. Percent Cows Leaving Herd
32
STATE AVERAGES
Milk
22,817
Percent butterfat
3.51
Percent protein
2.90
Pounds butterfat
793
Pounds protein
666
UNAVAILABLE
AT PRESS
TIME
HIGH COW REPORT
MAY 2006
MILK
Arizona Owner
* Stotz Dairy
* Withrow Dairy
* Mike Pylman
* Mike Pylman
* Mike Pylman
* Mike Pylman
* Dairyland Milk Company
* Mike Pylman
* Stotz Dairy
* Stotz Dairy
Barn#
16361
8894
789
1128
20160
724
1754
1392
18980
17385
Age
05-06
03-00
03-02
07-09
02-02
03-02
05-04
02-02
03-05
04-08
Milk
40,180
39,920
35,450
34,670
34,100
33,820
33,540
33,470
33,450
33,250
* Stotz Dairy
* Stotz Dairy
* Withrow Dairy
* Dutch View Dairy
* Dairyland Milk Company
* Stotz Dairy
* Stotz Dairy
* Danzeisen Dairy, Llc.
* Mike Pylman
* Mike Pylman
16361
18980
8894
170
1123
15883
11537
4854
789
85
05-06
03-05
03-00
04-02
05-03
05-08
09-00
04-06
03-02
05-00
1,477
1,430
1,358
1,354
1,333
1,283
1,266
1,265
1,262
1,259
* Stotz Dairy
* Mike Pylman
* Withrow Dairy
* Mike Pylman
* Parker Dairy
* Stotz Dairy
* Dairyland Milk Company
* Mike Pylman
* Mike Pylman
* Mike Pylman
16361
789
8894
20102
7243
18980
1754
724
21133
1392
05-06
03-02
03-00
02-01
05-07
03-05
05-04
03-02
03-01
02-02
1,195
1,088
1,059
1,017
986
986
979
967
956
953
New Mexico Owner
* Providence Dairy
* Butterfield Dairy
* Providence Dairy
* New Direction Dairy
* Pareo Dairy
* Pareo Dairy
* Butterfield Dairy
* Providence Dairy
* Providence Dairy
* Pareo Dairy
Barn #
5348
798
5395
231
1655
3780
1254
5726
8922
4183
Age
4-07
6-06
4-07
-----7-08
5-01
6-06
3-11
5-08
4-08
Milk
40,020
38,690
37,400
37,390
37,366
36,693
36,600
36,180
36,060
35,617
* Vaz Dairy
* Butterfield Dairy
* New Direction Dairy
* Providence Dairy
* Pareo Dairy
* Pareo Dairy
* Pareo Dairy
* Pareo Dairy
* Pareo Dairy
* Pareo Dairy
* New Direction Dairy
2782
1254
231
8922
8091
3780
1655
9454
1682
606
816
4-03
6-06
----5-08
9-06
5-01
7-08
7-07
7-07
5-04
-----
1,439
1,428
1,387
1,309
1,300
1,292
1,289
1,285
1,284
1,280
1,280
231
1254
816
5395
5366
798
Nt Hos
4654
4926
607 Hos
-----6-06
----4-07
4-07
6-06
------5-11
5-07
-------
1,203
1,124
1,108
1,108
1,095
1,091
1,090
1,088
1,079
1,075
FAT
PROTEIN
*all or part of lactation is 3X or 4X milking
* New Direction Dairy
* Butterfield Dairy
* New Direction Dairy
* Providence Dairy
* Providence Dairy
* Butterfield Dairy
* New Direction Dairy
* Providence Dairy
* Providence Dairy
* New Direction Dairy
ARIZONA - TOP 50% FOR F.C.M.b
MAY 2006
OWNERS NAME
* Stotz Dairy West
* Stotz Dairy East
* Mike Pylman
* Joharra Dairy
* Del Rio Dairy, Inc.
* Red River Dairy
* Zimmerman Dairy
Parker Dairy
* Danzeisen Dairy, Inc.
* Arizona Dairy Company
* Withrow Dairy
* Dairyland Milk Co.
Paul Rovey Dairy
* Goldman Dairy
* RG Dairy, LLC
* Shamrock Farm
* Yettem
Lunts Dairy
* Dutch View Dairy
* Saddle Mountain
Number of Cows
2,110
1,100
7,893
1,400
1,373
5,181
1,180
4,133
1,462
5,564
5,285
2,978
349
2,176
1,231
8,431
2,740
596
1,775
3,029
MILK
28,271
25,109
25,766
25,487
24,717
24,746
24,264
23,186
23,598
23,909
24,353
23,377
23,123
23,045
22,565
23,388
19,024
21,433
20,891
21,308
FAT
1,015
909
890
872
871
864
862
841
830
816
801
818
821
795
791
754
866
784
740
720
3.5 FCM
28,678
25,592
25,568
25,156
24,807
24,706
24,465
23,658
23,658
23,566
23,514
23,368
23,307
22,852
22,579
22,335
22,264
21,976
21,029
20,885
CI
14.8
15.2
14.3
13.2
12.9
13.8
14.7
14.6
14.6
14.4
13.2
13.6
13.5
13.8
13.9
13.7
13.2
13.2
14.1
14.2
3.5 FCM
26,143
25,646
25,397
25,100
24,866
24,843
24,729
24,445
24,031
23,823
23,722
23,365
23,057
DIM
129
163
138
155
160
150
148
136
134
139
141
116
121
NEW MEXICO - TOP 50% ACTUAL MILK
MAY 2006
OWNERS NAME
* Providence
* New Direction 2
* Do-Rene
* Vaz
* Tallmon
* Vaz
* Vaz
* Macatharn
* SAS
* Pareo
* Butterfield
* Hide Away
* Cross County
Number of Cows
2,872
2,222
2,432
581
470
1,976
1,395
883
1,881
3,469
2,086
2,636
3,637
MILK
26,333
24,809
25,359
24,784
24,692
24,451
24,301
24,581
24,187
23,330
24,222
25,309
22,721
FAT
910
920
890
887
875
880
877
852
837
847
817
766
816
* all or part of lactation is 3X or 4X milking
average milk and fat figure may be different from monthly herd summary; figures used are last day/month
b
ARIZONA AND NEW MEXICO HERD IMPROVEMENT SUMMARY
FOR OFFICIAL HERDS TESTED MAY 2006
ARIZONA
1. Number of Herds
NEW MEXICO
40
27
2. Total Cows in Herd
71,795
43,426
3. Average Herd Size
1,795
1,608
90
87
5. Average Days in Milk
211
197
6. Average Milk – All Cows Per Day
66.3
66.2
3.5
3.6
68,885
37,424
72.3
76.1
82
73
11. Average Days Open
160
142
12. Average Calving Interval
14.1
14.0
86
83
14. Percent Somatic Cell – Medium
8
11
15. Percent Somatic Cell – High
6
5
16. Average Previous Days Dry
60
64
17. Percent Cows Leaving Herd
31
27
4. Percent in Milk
7. Average Percent Fat – All Cows
8. Total Cows in Milk
9. Average Daily Milk for Milking Cows
10. Average Days in Milk 1st Breeding
13. Percent Somatic Cell – Low
STATE AVERAGES
Milk
22,821
23,522
Percent butterfat
3.51
3.56
Percent protein
2.90
3.05
Pounds butterfat
795
839
Pounds protein
666
714
UPCOMING EVENT:
ARIZONA DAIRY PRODUCTION CONFERENCE
OCTOBER 10, 2006
SHERATON PHOENIX AIRPORT HOTEL
TEMPE, AZ
PRSRT STD
U.S. POSTAGE
PAID
TUCSON, ARIZONA
PERMIT NO. 190
Department of Animal Sciences
PO Box 210038
Tucson, AZ 85721-0038
Phone: 520-626-9382
Fax: 520-621-9435
Email: ljr22@ag.arizona.edu