By Lance Kennington, PH.D., animal nutritionist, CHS
In my line of work, I often get the chance to hear from industry experts. At the Montana Nutrition Conference, I heard an interesting talk by Dr. Cliff Lamb, who now heads the Department of Animal Science at Texas A&M University. He had some interesting guidelines for selecting cattle and improving the herd by putting pressure on reproduction.
Here’s my takeaways:
- Pregnancy has a four times greater economic impact than any other production trait.
- Your goal should be to have the majority of the calves born in the first 30 days of calving season.
- Heifers must calve by 24 months; cows should calve every 365 days with no assistance. They should be able to express the genetic potential of the calf, maintain body condition score and be gentle.
- Temperament is highly correlated with reproduction. The wilder the cattle, the lower the reproduction rates.
- Retain in the herd only those heifers that become pregnant in the first 25 days. This will improve longevity and also calf weaning weights. Over their lifetime in the herd, they will produce up to 3/4 of a calf more than the other cows.
- Heifers who are developed fat will need to be fat to achieve estrus, whereas heifers developed to be leaner will be able to reach estrus at a more moderate body condition throughout their life.
- Producers should synchronize estrus and use fixed-time breeding when artificially inseminating (AI) heifers.
- AI pregnancy rates average 42-67 percent. Remember that those were the ones that were bred first service!
- If AI pregnancy rates are low or disappointing, remember that variables such as weather, forage quality and other variables which change a lot year to year are more likely to affect reproduction rates. Look at those variables first.
- AI and estrus synchronization doubles the number of calves born in the first 30 days.
- Don’t be afraid to cull non-productive females.
You can improve production and subsequently profitability in your herd a great deal by putting pressure on reproduction.