March April 2017 Kentucky Dairy Notes - Russell CountyThe International Precision Dairy Farming Conference was held in Leeuwarden, Netherlands from June 21 to June 23, 2016. Researchers,

Kentucky Dairy Notes March-April 2017

Timing of Insemination and Gender

By: Dr. George Heersche, Jr. At a recent dairy meeting one of the producers asked if timing of insemination influences the gender of the newly created life. Researchers at the University of Wisconsin-Madison looked into this several years ago and the results are briefly summarized in the table. In their study, ovulation was synchronized using a GnRH-prostaglandin-GnRH protocol, and ovulation occurred 24-32 hours after the second GnRH.

If cows were inseminated early and way before ovulation, the results were a higher percentage of females, a lower conception rate, but very little pregnancy loss for the cows who did get pregnant. If cows were inseminated late and close to or after ovulation, the results were a higher percentage of females, a lower conception rate, and a higher pregnancy loss for the cows who did get pregnant. So the answer to the question "Does timing influence gender?" is yes, but getting more heifers by this method is accompanied with lower fertility particularly when insemination is close to ovulation. The best overall results were achieved when cows were inseminated 16 hours after the second GnRH. This continues to be the recommended time of insemination for cows bred at the end of a synchronized ovulation protocol.

Reproductive measures in lactating Holstein cows inseminated at specific times in relation to ovulation

synchronized by an injection of GnRH.

Time from second GnRH until AI

0 h 8 h 16 h 24 h 32 h Total

Cows 149 148 149 143 143 732

Conception Rate

%

37 41 45 41 32 39

Pregnancy Loss % 9 21 21 21 32 22

Calving Rate % 31 31 33 29 20 29

Twinning Rate % 0 6.5 0 2.5 3.5 2.4

Female: male % 61:39 45:55 54:46 54:46 65:35 55:45

Looking to the Future with Precision

Dairy Farming

By: Amanda Lee and Jeffrey Bewley

The International Precision Dairy Farming Conference was held in Leeuwarden, Netherlands from June 21 to June 23, 2016. Researchers, veterinarians, producers, students, and industry members from around the world came together to visit farms across the Netherlands, present current research, and discuss new technology to improve worldwide understanding of

dairy cattle.

To help the attendees develop a better understanding of the European dairy industry, multiple farms using precision dairy technology hosted the conference participants. Dairy Farm “Dem Hartog” was in the North Friesian countryside. Milking 500 cows in a rotary parlor, the Dem Hartog family uses technology to modernize their dairy operation. The rotary consisted of 40 stalls, and 2 DeLaval (Tumba, Sweden) pre- and post-dip spray machines. Milking the cows twice daily, 150 cows were milked each hour and could be separated immediately after milking into distinct pens for pregnancy checks, trimming, or health checks. The family boasted of a cull rate near 15%, compared to the Netherlands national 27% average. Their current daily production was near 68 pounds, with a 4.45% milk fat and 4.05% protein. CowManager SensoOr (Utrecht, The Netherlands) was used to track eating time, activity, ear temperature, and heat detection within their herd. CowManager SensoOr were also applied to calves to assist in detecting fevers associated with bovine respiratory disease and diarrhea. Additionally, the farm had a water purification system (Watter!) to ensure clean water in all the water troughs. The company suggested that a purifying system can increase daily drinking by 7 gallons per cow, resulting in

better health and production.

The second family farm visited, “Boersma,”operated 8 DeLaval robots for milking, Herd Navigator for tracking activity, and DeLaval’s automatic body condition score camera for monitoring health. With the purchase of the DeLaval robots and Herd Navigator, the producer started producing 2.15 more lbs of milk per cow for $0.05 less per cow. The herd averaged 4.05% milk fat and 3.6% protein milking with the robots. The farm also boasted of a straw calving area and guided cow traffic, allowing the producers to easily separate cows for health and pregnancy checks. The DeLaval automatic robots used force flow traffic, so cows had to visit the automatic milking system before lying down. Cows passed under the body condition score camera after each milking to track changes in body condition throughout lactation. The camera helped to identify cows with rapid changes in body condition so

the producer could evaluate transition period management.

The final visit was to the Kalma family farm milking 450 cows on 3 GEA (Dusseldorf, Germany) robots. By putting their

robots in the middle of the barn, all cows had to travel an equidistant to the machines to reduce cow flow problems. The producers also invested in a locational tracking system through GEA that allowed them to track cow location 24 hours per day. The system registered which cows were in the freestalls, at the feedbunk, or in the milking machines so a producer could spend less time searching for cows. Additionally, the producer

focused on feeding a partial mixed ration using green chop.

In addition to farm visits, multiple researchers and industry professionals presented current research in dairy technology. Researchers from University of Calgary and University of Kentucky teamed up to validate Smartbow (Weibern, Austria), an ear-based real time locational technology. Using University of Kentucky’s old freestall barn, a two-part study was conducted to determine the accuracy of SmartBow. Smartbow was determined to accurately measure real-time cow location within approximately 3 feet of the actual location. Smartbow could help all producers find specific cows within a housing structure and determine how cows’ spend their time within a

facility.

Researchers at the University of Sydney explored methods to encourage grazing cows to walk to the automatic milking systems while providing heat stress abatement. Australian producers face hot temperatures and long walking distances during the summer months. Therefore, enticing cows to the parlor is crucial for dairy operations’ success. Using movable, shaded, lightweight structures, along the path to the parlor increased cow movement without requiring additional labor. By providing three additional 100 ft2 shaded zones on the path to the parlor, cows spent greater time stopped underneath the shade, but showed no increase in milk production or decrease in body temperature. More research into heat stress and cow movement must be pursued in order to better understand

manipulating grazing herds’ movement under heat stress.

Keynote speaker Dr. Schukken, the Chief Scientific Officer at GD Animal Health in Deventer and a Professor of Management of Farm Animal Health at Wageningen University discussed the use of technology to improve heat detection and cow health versus blanket protocols. As technology becomes more prevalent, producers must consider the cost of investing in new technologies versus the cost of treating individual cows or blanket treatment protocols. Across multiple studies, researchers determined that some blanket protocols can be more effective management tools for cows than individual protocols for each cow. Looking at heat detection, cows had a higher conception rate and decreased days open using technologies rather than sync protocols. Additionally, blanket dry off treatment for mastitis resulted in a decreased risk of mastitis after calving compared to individual cow and quarter treatments. As technology increases in accuracy and demand for decreased antibiotic use becomes more prevalent, the dependence on technology may increase. However, Dr.

Schukken suggested that technology must be used in

conjunction with common sense and good farm management to

be most effective.

A few new technologies were also highlighted at the Precision Dairy Conference. For grazing herds, invisible fences have become the next way to manipulate grazing patterns without producer’s moving gates or expensive infrastructure. Using invisible electric signal, cows hear a sound when entering within a certain distance of the invisible fence. If they ignore the sound, and continue, cows then receive a small shock to indicate that cows cannot graze in that area. Researchers reported that cows

learned to listen to the alert within one to two days.

Tail mounted calving devices also have become more prevalent as a method to predict calving date. Because studies have shown an increase in tail movement directly before calving, the devices are mounted at the base of the tail with greater tail head movement indicating calving. Subsequent alerts are also released to give a better prediction of calving time. With better information about calving, producers may be better able to check and aid

cows requiring assistance.

To better understand how cows move, research is being conducted using pressure mats to track foot placement, distance between steps, and pressure applied to specific regions of the hoof. Monitoring the way lame and sound cows walk may help to better objectively diagnose lameness in cows, although they are not yet commercially available. Because mats require fewer steps than typically needed for visual or video observation, ulcers, foot rot, and other hoof problems could be detected and addressed

earlier.

If you are interested in attending a similar conference this year, the Precision Dairy Farming conference will be head in Lexington, Kentucky May 30 to June 1, 2017. There will be an opportunity to explore some of the technologies discussed and new innovative technologies the University of Kentucky is researching. For more information, check out: http://

www.precisiondairyfarming2017.com/.

International Precision Dairy Farming

Conference 2016 . . . continued

Improving Ventilation in Dairy Cow Barns

By: Selene Reeves and D.M. Amaral-Phillips

Many health and financial problems associated with increased moisture, odor, and high temperatures can all be greatly reduced by improved ventilation in dairy barns. Increased temperatures are a direct contributor to heat stress. Dairy cows exhibiting heat stress have reduced feed intake, decreased fertility and reduced milk yield. If heat stress is not reduced, major financial losses can ensue. Barn design, including roof design, barn dimensions, proximity of neighboring barns, and the overall orientation, are crucial to maximize natural air flow. The proper use of fans, curtains, and temperature sensors can help further improve ventilation within the barn. Discussed below are specific changes that can be made to

improve barn ventilation.

Designing a New Barn

Roof Pitch The roof pitch allows moisture and gases, from within the barn, a place to quickly move up to the ridge vent. Preferably, the roof pitch should be 4 feet in the vertical direction for every 12 feet in the horizontal direction or 4:12. Roof pitches that are lower or

steeper may not be suitable for dairy cows.

Ridge Vent The ridge vent in combination with a recommended roof pitch allows warmer air to flow out of the top of the barn. The ridge vent should be one-foot wide with an additional three inches for every 10 feet of total barn structure width beyond 40 feet. If a ridge cap is used, the distance between the cap and the roof below should be at least three quarters the width of the ridge vent. For example, the distance between the ridge cap and the

roof below for a 1 foot or 12 inch ridge vent should be 9 inches.

Sidewall Openings On average, there should be a 14 to 16 foot sidewall height for large amounts of air to enter and exit the barn. In combination with a good roof design, a natural cooling effect passes the stale air out at a quicker pace with increases in eave height. Any barn curtains should be raised up for maximum air flow in the

summer.

Orientation of Barns Barn orientation should be in the east/west direction. Because the sun rises in the east and sets in the west, direct sunlight is minimized. Also, in some locations an east/west orientation is in the same direction as natural outside air flow, thus making it

easier for air to flow throughout the barn.

Closeness of Other Barns If adjacent dairy barns are too close in proximity, natural ventilation will be reduced. The minimum space recommended between neighboring barns is 80 feet. The larger the dairy barn, the more distance needs to be between the barns with 100 feet

or more recommended for larger dairy barn structures.

Improving Barn Ventilation

Curtains Curtains used as side walls can be adjusted to maximize air flow depending on the season. As mentioned previously, curtains should be fully raised in the summer to maximize air flow. In the winter, the lack of air flow will

create condensation resulting in an odorous and humid environment. Curtains should allow an open space at the top of the barn opening one half of the ridge opening width so that air can still flow throughout the barn at a minimum

of 4 air exchanges per hour.

Fan Placement

High-Volume, Low Speed (HVLS) Fans HVLS fans are used to circulate natural air thorough all areas of the barn. These fans are named due to their large size (8 – 24 feet diameter) and slow moving speeds (45 revolutions per minute for a 24-foot fan). For a 24 foot HVLS fan, there should be 60 feet between each fan if they span down the center of the barn just over the feed alley. If used correctly, moisture, heat, and odor can all be greatly

reduced.

Box Fans Also known as simple circulation fans, box fans are smaller than HVLS fans. These fans can provide improved air circulation if an adequate number are placed strategically around the barn. Commonly, these fans can range anywhere from 36” to 50” and, therefore, should be spaced 30 feet for 36” fans and 40 feet for 48” fans apart at an angle that is below the downstream of the preceding fan. The larger the fan, more space will be required between each. Fan placement should be focused over the cow beds and feed

lanes.

Air flow from these fans can be reduced due to poor maintenance. Therefore, upkeep is necessary. Fan blades and grills should be cleaned free of dirt and dust. Regular oiling, realignment, tightening of the fan belts, and the replacement of damaged fans should all be completed

before each summer season.

Automatic Fan Control Fan operation should be dependent on fluctuations of outside temperature in order to prevent heat stress. For example, an increase in outside temperature should prompt an increase in overall fan usage. With an automatic temperature control system, fans should be turned on near 65°F to 68°F and turned

off below those temperatures as well.

Even the slightest alterations in dairy barn dimensions can have a large impact on air flow. Therefore, careful considerations of the initial design of the barn can provide maximum ventilation preventing various health and financial problems. In addition to barn design, producers should also take advantage of proper usage of HVLS fans, box fans, and curtains in both old and new

barns to help further improve air flow.

Heat Abatement for Dry Dairy Cows

By: Sarah Mac and D.M. Amaral-Phillips

Heat stress in dairy cows, irrespective if they are milking or dry, can

reduce feed intake, lower conception, increase health issues associated

with lower immunity, and lower milk production. This paper focuses on

dry dairy cows, although, all groups need heat abatement. In dry cows,

heat abatement is important because management practices in the dry

period determine the success in the lactation period and the health,

growth, and future performance of her calf. Monitoring and modifying

management practices relative to the temperature heat index can be a

solution to reduce some of these losses. Methods to cool dry cows are

fairly inexpensive and in the long run will make you money. Many farm-

ers have heat abatement protocols in place for their milking herd, but

when was the last time you reviewed your heat abatement program for

your dry cows? This article covers specifications recommended for

shade structures, fans, water, and ventilation so you can assess your

dairy to see if it follows the guidelines of professionals.

Dry Cows on Pasture:

Shade: If cows are on pasture, shade should be available and man-

aged to ensure the underneath surfaces do not become muddy

which can be a health risk. When using a shade structure, provide

at least 65 square ft/cow and these structures should be between

12 and 16 ft tall. Shade structures can be covered with shade cloth

which blocks 80% of sun or roofs should be white colored galva-

nized metal or aluminum to provide maximal solar reflection. If

shade comes from trees, they should be rotated by fencing them off

to prevent mud pits. Mud pits lead to increased numbers of environ-

mental bacteria and can result in mastitis.

Center Pivots: Center pivots can be used as a sprinkler system for

cows on pasture. They need to be continuously moving to prevent

mud spots. A shade cloth over the irrigation system is recommend-

ed to provide the cows with shade. Not only can this system give

heat abatement, it can increase the nutritional value of the grass

through irrigation of the growing forage crop.

Feedbunk: Feed should be shaded to prevent spoilage and main-

tain the nutritional value. Keeping feed cool can also maintain /

increase feed intake, which is especially important in dry cows close

to calving. Sprinklers and fans should be found above the feedbunk

on the side where cows stand, if possible.

Dry Cows in Housing Facility:

Ventilation and fans: Fans should be placed above feed bunk and

freestalls or bedded pack. Air velocity in any barn should be about 4

to 6 MPH. Fans should be cleaned and repaired regularly. If free-

stalls are used, there should be a 1:1 ratio of stall rows to row of

fans. Fans should be angled at 15 to 20 degrees. The open ridge

should be sized to provide 3 inches for every 10 ft of barn width.

Cows should have 14 to 16 ft of open wall space for natural air to

flow in (unless it is a tunnel ventilated barn).

Barn Orientation: Barns should be built east to west to prevent

direct sunlight shining into the barn. In the summertime, minimizing

sunlight entry into a barn can be critical to improve cow comfort,

freshness of feed, and decreasing temperature within the barn.

Sprinklers and Water: Clean, fresh water should be available for

the cows’ consumption without obstruction. Location of water

troughs should be within 50 feet of resting area and should be in the

shade. There should be a minimum of 2 water troughs per pen, and

should have 3 inches per cow in that pen. For example, if there is a

pen of 40 cows there should be a total of 10 feet of trough space.

This means there should be two, 5 feet water troughs. Sprinklers

should be placed along the feed bunk and soak the cow’s skin and

are more effective when paired with fans. The ratio of on to off time

is 2 minutes on for every 10-12 minutes off. Fans should run con-

tinuously once the temperature reaches 65°F. Thus, recommenda-

tions are identical to those for the milking herd.

Why Does this Matter?

Cows calve 2 to 8 days early: Dams that were heat stressed gave

birth to calves 13 lbs lighter. These lighter heifers continued to have

lower body weight and height through 12 months of age.

Heifers born to heat stressed dams give less milk: Once that

heifer born to a heat-stressed dam calved, milk production was 11

lbs less than heifers born from dams not heat stressed.

Lowers milk production next lactation

Decreases conception rate

Lowers immune system: Fresh cows already have a compro-

mised immune system, but those cows under heat stress have a

greater risk of infection since immunity is even more compromised.

Take Home Message:

Heat abatement for dry cows is important and must be properly man-

aged. Remember to assess your dairy‘s heat abatement programs to

reduce heat stress on dry cows and their developing calves. If heat

abatement is available for dry cows, the overall health and performance

of the cows and their calves will increase. Milk production, fertility and

feed intake can be improved with adequate heat abatement.

University of Kentucky Barn built in 2016.

Effects of Heat Stress on Dairy Cattle

Reproduction

By: Katie Kelly and Donna Amaral-Phillips, PhD.

Reproductive failure is one of the main reasons that dairy farmers

cull dairy cattle. With lower reproductive performance, cows have

longer days open, longer lactations, reduced milk production per

day of life, and often produce less profit for their owners. Heat

stress has a big effect on the cow’s reproductive performance.

While most farmers know that the effects of heat stress on milk

production start at a temperature humidity index (THI) of 68, the

effects on fertility can start at even lower THI with some scientists

suggesting it may even start at a THI of 50. When heat stress

occurs, conception rate can decrease by 53%. Understanding the

causes for this decrease in fertility during heat stress and ways to

decrease these effects are discussed in this article.

Heat stress affects the cow and her calf:

Estrus expression is reduced. During periods of heat stress,

cows are less likely to show signs of estrus or heat which is

related to decreased amounts of blood hormones. Estrus

events are shortened and not as intense as during the winter

months. Without these visual signals, the farmer doesn’t know

that a cow should be bred and when a cow does not get semen

in her, the cow cannot conceive a pregnancy.

Developing follicles and sperm. This decrease in hormones

in the blood also prevents the normal development of ova.

Without this proper amount of hormones, the cow will

experience longer follicular waves and underdeveloped

dominant follicles. Additionally, heat stress inhibits sperm

development and reduces libido in bulls. Heat stress will cause

lower sperm concentrations, lower mobility, and more

deformities in the sperm. These service sire effects will

decrease the conception rate in a natural serviced herd.

Embryos can be heat stressed too. An embryo in heat

stressed cows can die within 17 days after fertilization because

the early embryo does not have proteins that help it combat

heat stress. When a cow is heat stressed, the cow’s core body

temperature rises. This increased heat inside the body is what

affects the embryo and without heat shock proteins, the embryo

will die, decreasing pregnancy rate. Heat stress also retards

the growth of young follicle which results in the weakening of

the signal that tells the cow that she is pregnant. Without this

signal from the embryo, the cow will stop secreting the

hormones needed to maintain pregnancy.

The fetus and heat stress. Not only does the cow have fertility

issues with heat stress, but the developing fetus can also have

fertility issues in the future. Calves from a dam that expressed

high levels of heat stress when pregnant are more likely to

require more services than calves whose dams had heat

abatement systems. Additionally, these calves are born with

lower birth and weaning weights and produced less milk in the

first lactation.

Managing heat stress: So now that some of the causes are

known, how can we minimize the effects of heat stress on

reproductive performance?

Turn on fans and sprinklers. Fans should be turned on

around a temperature of 65℉ and sprinklers around 70℉.

Sprinklers should be located over the feed bunk and in the

holding pen, while fans should be located at the feed bunk, in

the holding pen, and over every row of free stalls. The sprinkler

system should soak the cow for 2 minutes and then is turned

off for 15 minutes to allow the fans to create a breeze over the

cow to evaporate the water and heat. These time intervals

change as the temperature humidity index rises. When this

happens, the time between when the sprinklers are turned on

should be shortened.

Synchronization protocols and Timed AI. Synchronization

protocols help with the fact that cows are not showing as strong

of heats during heat stress periods. When these programs are

used with Timed AI protocols, the need for an observed estrus

is taken out of the equation. The use of Timed AI can reduce

the number of days open, and interval of calving to first

breeding when compared to breeding on observed estrus.

These programs can be found on the Dairy Cattle Reproductive

Council website. It is important to note that these programs

help with estrus detection during heat stress but do not change

the effects of heat stress on the oocyte. Cow cooling is need to

reduce the effects of heat stress after conception.

Embryo transfer. Another method to prevent embryo death

during heat stress periods is to transfer embryos from donor

cows which were not heat stressed. Not only can this improve

genetics, but it helps to bypass the susceptible stages of the

embryo to heat stress. At the point of the transfer into the

recipient, the embryo has the proteins needed to fight heat

stress. Research shows a $14 to $22 increase in profit from

embryo transfer. This range varies based on management of

the herd and the cows producing and receiving the embryos.

Heat stress is a major issue dairy farmers must mitigate on dairy

farms. Heat stress impairs not only milk production but, reproductive

ability as well. It reduces the tendency of estrus and decreases

embryo survivability. Simple techniques, such as turning fans and

sprinklers on and use of synchronization programs, can help

manage for better fertility during times of heat stress.