Wednesday, September 21, 2016

Thompson Research Center Field Day: Overview of reproductive research at the Th ompson Research Center

Dave Patterson

Patterson's research focus seeks to answer the question "Can we overcome the resistance to adopt AI with the development of fixed timed AI protocols?"

The Thompson Research Center has been involved with AI research since 1997 when the FDA was evaluating the use of CIDRs using cattle at the farm. In 1998, Patterson started using the center for his research and many students have been trained while working on projects at the research center.

The Show-Me-Select Program is designed to help producers understand the importance of heifer development based on reproductive success. There have been 271 veterinarians involved in the program and 123,091 heifers have been enrolled in the program. There have been $44,565,350 in gross sales through Show-Me-Select heifer sales. Ninety-five percent of the counties in Missouri have enrolled heifers in the Show-Me-Select program. Heifers from the Show-Me-Select program have been sold into 19 states. Heifers are classified as Tier II if they are sired by a proven AI sire. Tier II with an AI pregnancy see a $292 premium at sale. When the cattle market prices are high, there is smaller difference in premiums between the different classification of heifers in the sale. But, as the cattle market prices decrease, we once again see larger premiums for AI sired and AI bred heifers.

Reproductive tract scores help cattle producers know if a heifer is mature enough to bred. Reproductive tract scores can be collected by a veterinarian and help producers know which heifers to keep and bred and which heifers need to be culled. Heifers that have reached puberty earlier tend to do better in fixed-time AI protocols.

In 2010, 68% of heifers were bred at least one time by AI. In 2015, 90% of the heifers were bred at least one time by AI. Ultrasound pregnancy diagnosis has also increased drastically in the program.

Managing two-year-old cows presents a unique challenge in managing a beef herd, because they face many obstacles to re-bred. Patterson’s group is researching how to best synchronize these females for improved fertility rates. Protocols that use CIDRs help cycling two-year-olds get breed and help non-cycling cows start to cycle and get bred as well. With either a 14-day CIDR or 7-day CoSync + CIDR protocol, 88% of the two-year-old cows were pregnant in the first 30 days of the breeding season.

Can we improve pregnancy rates if we manage the cows differently in the AI synchronization protocol? Patterson's group is looking at split-time AI to improve pregnancy rates. In heifers, we can improve pregnancy rates by 15% using a split-time AI protocol. But, we don’t see any improvement in cow pregnancy rates. See "Split-Time AI: Using Estrus Detection Aids to Optimize Timed Artificial Insemination" for more information about split-time AI.

The 14-day CIDR-PG protocol for heifers with split-time AI.
The 7-day CO-Synch + CIDR protocol for cows with split-time AI.


The only heifers or cows that need a GnRH injection are only those that have not expressed estrus (heat). This means fewer shots and reduced costs.

Patterson’s group is also working on the development of a 9-day CIDR protocol. Preliminary results suggest that the 9-day protocol is having a much tighter grouping of the estrus response of the cows. On the 9-day protocol, there was a 17 percentage point improvement in pregnancy rates (77% vs 60%) compared with the 14-day protocol. In follow up projects, the 9-day protocol had a 10 point advantage.

Patterson urged producers to make sure that you are using the current years AI protocols sheets.

In the last 10 years, we have doubled the amount of semen that is sold. Fixed-timed AI protocols have made artificial insemination easier to accomplish.

As the market turns down, how can you distinguish your cattle from the rest of the market? Using reproductive technologies is a great way to differentiate your cattle.

Next year’s Applied Reproductive Strategies in Beef Cattle meeting will be in Manhattan, Kansas. Previous years proceedings may be seen on their website, http://beefrepro.unl.edu/proceedings.html.

Decker's Take Home Message
Artificial insemination allows beef breeders access to much better bulls than a typical natural service bull. Fixed timed AI protocols have made it much easier to implement an AI program.
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