Yet many of the phone calls I receive in September through November regarding less-than-desirable pregnancy rates often could have been avoided with attentiveness to a few key areas.
1. Nutrition – I write about nutrition almost every month because proper nutrition is the backbone to all other processes in the herd. There is nothing in a bottle that can be administered to fully overcome poor nutritional management. Both heifers and cows need to be on an increasing plane of nutrition heading into the breeding season.
It should also be noted that if your breeding season coincides with early lush spring pasture, excessive moisture in that forage may require supplementation for cows to meet their dry matter and, thus, energetic requirements.
2. Bull management – I brought this up last month and will say it again. If you have not conducted breeding soundness exams, please do so. This is as cheap an insurance policy as you can buy for your breeding season. Also, be cognizant of proper bull-to-cow ratios.
A rule of thumb is one cow per month of age of the bull up to 3 years old. Along the lines of No. 1, bulls can easily lose 10 to 15 percent of their bodyweight during the breeding season. “Lean and mean” is a dangerous motto I hear frequently at the beginning of the breeding season. Bulls should not be fat – but they should be approaching a body condition score of 6 at turnout to serve as a nutritional buffer.
3. Handling of hormones and A.I. equipment – Cleanliness is next to godliness. Dirty needles, A.I. guns and hands immediately diminish what the potential was for pregnancy success to A.I. and embryo transfer. GnRH should remain cold throughout the period of use. Prostaglandin should be stored at room temperature, and if it has ever been frozen (or possibly frozen), throw it out because it will no longer be effective.
As always, consult with the team of experts you have assembled including your beef extension specialist, nutritionist, veterinarian and agronomist, and visit www.iowabeefcenter.org for all things beef. 
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Patrick Gunn
- Assistant Professor of Animal Science
- Iowa State University
- Email Patrick Gunn
