Newsletter – 2015 – April

Supplemental Vitamin E Helps Reduce Retained Fetal Membranes

Retained fetal membranes (RFM) in dairy cattle are never a good thing. The occurrence of RFM is associated with subsequent uterine infections and productive and reproductive losses. Researchers recently looked into the effect of supplemental vitamin E on reducing RFM incidence. The results were reported in the April 2015 Journal of Dairy Science.

Vitamin E status and supplementation prepartum have been linked with risk of RFM. In this study, 890 cows were fed diets that contained less vitamin E than recommended by the National Research Council. The cows also either received or did not receive weekly doses of 1,000 IU of vitamin E starting three weeks prior to calving.

Results indicate that supplementation with injectable vitamin E decreased the incidence of RFM. In addition, cows that received the weekly Vitamin E treatment also had improved pregnancy per artificial insemination and pregnancy rate in the following lactation.

Access the abstract.

Progesterone Increases Reproductive Performance
A recent meta-analysis of progesterone supplementation during synchronization of ovulation protocols for timed artificial insemination (A.I.) in dairy cows was published in the April 2015 Journal of Dairy Science.

The systematic review of the literature evaluated the effects of progesterone supplementation during timed-A.I. on fertility of dairy cows under various management systems. Results showed that progesterone supplementation:

• Increased the risk of pregnancy by 10%
• Tended to reduce pregnancy loss in the first 60 days of gestation

Plus, a benefit to supplemental progesterone was observed in studies during which all cows were inseminated at a fixed time with no detection of estrus during the synchronization protocol and in cows without a corpus luteum at the initiation of the synchronization protocol.

This work will be presented by the author in detail at the Annual Meeting.

Access the abstract.

Another Reason for Genomic Testing
Until now, genomic information has mainly been used to improve the accuracy of genomic breeding values for breeding animals. However, Danish researched hypothesized that the use of information from genotyped females also opens up the possibility of reducing genetic lag in a dairy herd. Their research was published in the January 2015 Journal of Dairy Science.

The scientists felt the opportunity to reduce genetic lag occurs especially if genomic tests are used in combination with sexed semen or an increased level of reproductive management. In this study, sexed semen was used in combination with beef semen to produce high-value crossbred beef calves.

The results showed that the use of genomic tests for decision making decreased genetic lag by as much as 0.14 genetic standard deviation units of the breeding goal. And that genetic lag decreased even more (up to 0.30 genetic standard deviation units) when genomic tests are used in combination with strategies for increasing and using a reproductive surplus. Of course, genetic test cost is a significant factor in the total impact on profitability.

Access the abstract.

Genomic Selection for Improved Dairy Cow Fertility
By Dr. José Santos, Animal Science professor, University of Florida

Fertility is a fundamental component of success for modern dairy farms. As a result, fertility challenges carry serious financial and production risks for each operation.

For instance, limited fertility or the failure to get cows to conceive in a timely manner will extend the lactation and reduce the percentage of cows at peak production, increase insemination cost from repeat breedings and eventually delay genetic progress.

In addition, impaired or reduced fertility, which lead to low milk production, are often the reasons to remove a cow from the herd. That’s because cows with extended lactation due to increased days open are often associated with a greater risk of herd removal in the current and subsequent lactations.

Over time the dairy industry has encountered an overall trend in declining dairy fertility across diverse production systems. There are a number of reasons that may explain this performance dip, including changes in cow physiology tied to greater milk production, nutritional management, housing, increased herd size, reduced estrous expression and current genetic makeup.

Stop the Trend
Despite the changes that have occurred, healthy cows still achieve high pregnancy rates. But early lactation disease can quickly negate this performance.

The question then becomes, can genetics help producers improve fertility by breeding cows that carry a better make up of genes for fitness traits such as health and fertility?

The answer seems to be, at least partially, yes.

Although fertility traits are strongly influenced by the environment, there is evidence to support the influence of genetics on reproductive performance.

Effect of DPR
There has been an important rise in phenotypic daughter fertility and a smaller, but also positive increase in the genetic trend for daughter fertility since the incorporation of daughter pregnancy rate (DPR) into bull genetic evaluations in 2003. Using this parameter, concurrent with improved reproductive management, producers found that it is possible to select for improved milk yield and fitness traits including fertility.

As a result, there’s been a bit of a recovery in dairy fertility that has coincided with the incorporation of DPR into bull genetic evaluations. This improvement occurred even while there’s been no apparent slowing down in the increase of milk production per cow.

Furthermore, indirect selection for fertility has occurred since reproductive efficiency is essential for the cow’s ability to remain in the herd.

Genetic Progress Continues
The use of DNA analysis in the evaluation of dairy cattle genetics is increasing. And USDA’s genomic evaluations are official since 2008, giving the industry a good base of knowledge for informed decisions.

This technology has the potential to influence reproductive performance in many ways. For instance, from the perspective of embryo production efficiency, markers associated with the number of viable oocytes, fertilization, cleavage and developmental rates have been explored.

Quantitative markers have also been identified for ovulation rate, pregnancy rate, DPR, cow and heifer conception rates, non‐return rate, intensity of estrus and calving performance. These markers have also have been identified for gestation duration, dystocia and stillbirth and overall postpartum fertility.

In addition to the potential for genomic selection for fertility traits, this technology has offered the capability of locating lethal recessive genes. Researchers have identified a number of new recessive defects on fertility in Holsteins, Jerseys and Brown Swiss. These recessive lethal genes affect reproduction by reducing conception and increasing pregnancy loss or the risk of stillbirths.

These advances help producers improve herd reproductive performance.

The Future

Current efforts are underway by multiple research groups including an integrated project at Texas A&M, University of Florida, University of Wisconsin, Ohio State University, Cornell University, University of Illinois and University of Minnesota to learn more.

Researchers have collected a large number of accurate fertility phenotypes (observable characteristics) in 16 farms in four regions of the United States that encompass different management and environments to identify genomic markers associated with those phenotypes. This large scale evaluation of genomics of fertility will eventually be combined with current selection traits to further refine genomic selection of cattle by dairy producers.

Although the genetic trend for daughter fertility has slightly increased during the last decade, future progress will benefit from the development of genomic estimated breeding values for measures of fertility less likely to be influenced by management decisions. Identifying markers for genomic selection for uterine health, early resumption of postpartum ovulation, detection of estrus, conception and reduced pregnancy loss will embrace a new step in improving fertility of cattle.

Lastly, as the cost of genotyping decreases, the number of animals with genomic evaluations is expected to increase. If adequate markers for fertility and further identification of genetic causes of infertility in dairy cattle are identified, molecular breeding values could be more accurately estimated for each trait. This would enable the adoption of efficient selection throughout the entire dairy industry.

Harry Anderson
Anderson Breeding Services and Advanced A.I. Services
Modesto, California
Member since 2006

Our business provides professional artificial insemination (A.I.) services to our clients. Anderson Breeding Services was started by my father Gene Anderson in 1951. Today we employ five full-time technicians and one part-time technician. We are responsible for the reproductive programs for 12 dairies, or approximately 15,000 cows. Advanced A.I. Services was established in 2014 and trains technicians to achieve a higher skill level.

My responsibilities for the organizations are to oversee the daily operations and consult with our dairies to make improvements in reproductive efficiency. I also train A.I. technicians to professional standards.

I have been around the A.I. industry all my life. My dad started the business the year I was born. I started breeding cows in 1974, and worked with my dad for three years as an apprentice. I also attended Modesto Junior College and graduated with an A.S. degree in artificial insemination. Since that time I’ve advanced my training through Embryo Transfer School, A.I company training (SRS) and DCRC conferences.

I have been a member of DCRC since the beginning and have attended every conference except one. The conferences have helped me understand what affects reproduction and how to make improvements to increase reproductive performance.

Reproduction Performance Emphasis

I always have been fascinated with how the process of reproduction works—it’s amazing! I think we take it for granted because we see it every day. But, it truly is God’s creation in progress. It’s a miracle and no accident. Also, I know how important reproduction is to a dairy’s financial success. The better we can do with reproductive performance, the more profitable the dairy becomes.

Two things that have been important in improving and maintaining the reproductive performance that we have been able to implement within our client dairies are: 1.) nutrition and 2.) transition.

• Nutrition: Dr. Jose Santos’s presentation on the three levels of nutrition was extremely valuable. Also other sessions on nutrition and the role it plays on reproduction have been beneficial to help understand the importance of nutrition.>/li>
• Transition: The research on the importance of the transition period and how it sets the stage for the next lactation both for reproduction and production was another great take-home message.

Reproductive Challenges
I still feel the two most important areas we continually have to focus on are nutrition and transition. If dairies are doing a good job in these two areas we usually will have a sound reproduction program.

So what’s next? How do we take or reproduction to the next level? I believe that the next challenge is to improve the skills of A.I. technicians. I feel the A.I. industry can—and must— do more to train technicians to the higher skill levels needed today to improve reproduction performance. The industry is changing and the cows are also. Estrous expression has changed. Also the use of timed-A.I. programs and the use of estrous detection systems all influence how we breed cows.

It is vitally important that the skill levels of A.I. technicians improve through additional training. If we enhance the skill levels of A.I. technicians it would have a great impact on increasing dairy reproduction performance—which should be the ultimate goal.

Thanks to all the people and organizations associated with DCRC that continue to help make improvements in dairy cattle reproduction.

• Minnesota Dairy Health Conference, May 6 – 8, Bloomington, Minn.
• DCRC Webinar, May 27, 11 AM (CDT) featuring Dr. Overton
• 2015 4-State Dairy Nutrition and Management Conference, June 10 – 11, Dubuque, Iowa
• Conference on Precision Dairy Farming, June 24 – 25, Rochester, Minn.
• ADSA® – ASAS Joint Annual Meeting, July 12 – 16, Orlando, Fla.
• American Association of Bovine Practitioners Annual Conference, September 17 – 19, New Orleans, La.
• World Dairy Expo, October 29 – October 3, Madison, Wis.
• 2015 DCRC Annual Meeting, November 12 – 13, Buffalo, N.Y.