ARSBC 2018: Considerations for utilizing reproductive technologies in Bos indicus-influenced cattle

Jordan Thomas
University of Missouri

Bos indicus cattle are different from Bos taurus cattle. They were domesticated at a different time, in a different location from a different population than Bos taurus cattle.

The big difference between Bos indicus cattle and Bos taurus is the attainment of puberty. Bos indicus cattle reach puberty later on average. Nutrition does not cause earlier puberty, but adequate nutrition is necessary to express potential for puberty. Brahman influenced animals are very sensitive to lower target weights and their ability to reach puberty.

Modern compound bows have multiple sights for different distances. Even if we use perfect form, but use the 20 yard sight to shot a target at 60 yards, we will miss the target. We often make this same mistake when trying to hit mature cow weight targets. Cull cow weights can help us better identify the mature cow weight target.

Reproductive tract scores are a helpful tool in managing Bos indicus-influenced heifers.

Bos indicus-influenced cows are likely to have higher rates of anestrus at the start of the breeding season.

Bos indicus cattle also appear to be less sensative to GnRH products. This affects which protocols work best in Bos indicus-influenced cattle.

Generally, Bos indicus-influenced cattle are more susceptible to stressors. Stress from handling and sorting can reduce success when using reproductive technologies.

Acclimating heifers to human handling can improve temperament, reduce cortisol, and hasten puberty. Temperment is moderately heritable and will respond to selection pressure.

Bos indicus-influenced cattle have a shorter length of standing estrus and are more likely to express estrus at night.

Bos indicus cattle and Bos indicus-influenced cattle really are different.

Estradiol is not FDA approved for use in cattle in the USA. This is not likely to change, due to fears of increased cancer risk from exposure to estradiol. Most Bos indicus synch protocols are developed in South America, where they do use estradiol.

The recommend protocol for Bos indicus-influenced cattle is the PG 5-Day Co-Synch + CIDR protocol. This protocol is also known as Bee Synch. GnRH may be removed from this protocol as additional research is conducted.

Field data suggests the 14-Day CIDR protocol in mixed puberty status groups of heifers.

Bos indicus-influenced heifers who are prepubertial really struggle in a fixed-time artificial insemination program. However, pubertal heifers do really well in an AI program.

Link to video of Thomas' presentation: https://www.facebook.com/AngusJournal/videos/333712244040324/

See ARSBC Newsroom for more information. http://www.appliedreprostrategies.com/2018/newsroom.html

Note: this post was live blogged and may contain errors.
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