AI programs require attention to detail

Mar 14, 2014
by WLJ

Critical Success Factors for AI: When it comes to reproductive management, exceptional performance in one area will not compensate for the mistakes you make. Reproductive success will never be better than performance in the weakest area:

• Temperament. Temperament will vary among animals and is both a safety and production (growth, reproduction, carcass quality) issue. Recent work done at Oregon State has reported a correlation between temperament and pregnancy success. Beef cattle with an excitable temperament have been reported to decrease the probability of pregnancy during the breeding season compared to calm herd mates.

• To achieve good pregnancy rate, estrus synchronization protocols must be followed precisely. To minimize the probability of making a mistake, a good practice is to write each of the days of treatment, the product name, dose to be administered, and the day of insemination on a calendar and ask a trusted veterinarian, extension specialist, or AI company representative to review it before beginning the protocol.

• Nutrition. Replacement heifers should be developed to an appropriate target weight (65 percent of mature weight) prior to the breeding season. Cows should also be fed to attain adequate body condition prior to calving (BCS 5). Therefore nutrition prior to the start of the breeding season is of obvious importance. However, nutrition following breeding can also have a direct effect on embryonic development and survival. Any dramatic changes in diet or feed intake following breeding that result in weight loss can negatively impact pregnancy rate and should be avoided.

• Vaccination Program. A pre-breeding vaccination program in combination with careful attention to biosecurity practices and reducing stress/disease transmission within a herd should be included in a herd health program. Several studies have reported injection of naive heifers with a MLV virus around the time of breeding resulted in ovarian lesions and decreased pregnancy rates. Therefore, general recommendations for pre-breeding vaccinations are that both heifers and cows should receive vaccinations 45 to 30 days before breeding.

• Post-AI shipping. Recent studies in Montana have reported that transporting cattle on a trailer decreased pregnancy rates by about 10 percent between days five and 42 after insemination and by 6 percent between days 45 and 60. The best time to ship cattle is before synchronization or within four days of breeding.

• Proper insemination technique. If you choose to artificially inseminate heifers or cows yourself, remember that the location of semen placement within the reproductive tract will have a significant impact on pregnancy rates. It is important to deposit the semen in the body of the uterus (target area) and not the cervix. Deposition in the cervix will significantly reduce the pregnancy rates. Furthermore, semen handling should not be overlooked, since improper handling of semen can reduce semen motility and also greatly reduce pregnancy rates. — George Perry, South Dakota State University