Breeding season options during drought
for Tri-State Livestock News
April has been an interesting month for weather. Those producers who have settled on April as a good month for spring calving found it to have been a bit too wintry this year, but the drought relief has been welcome. The million-dollar question is whether drought relief will continue, or whether drought-induced herd reduction will still be needed.
With calving winding down for many, breeding season is just around the corner. Breeding season management may need to be tailored to the potential for continued drought. If drought forces herd reductions, it would be best to base culling on production functionality in both cows and replacement heifers. Using a shortened breeding season will challenge the females in your herd to be fertile, and those that are not fertile enough to get pregnant early in a shortened breeding season will self-identify as candidates for culling.
Estrus synchronization can play a role in managing a shortened breeding season. Some producers use such an approach on replacement heifers even in wet years by keeping excess heifers and breeding them once on a synchronized estrus. Using this approach, or even a short breeding season such as 30 days so all females have one more estrus cycle to become pregnant, can be used on both heifers and cows. Basically, we are increasing selection pressure for fertility and if forced to sell, only the most fertile get pregnant and therefore get to stay. Pregnancy can be detected by ultrasound at about 45 days after breeding. Thus, non-pregnant females can be culled and sold as early as about 6 weeks after the synchronized breeding.
A major advantage of this approach in drought conditions is that it quickly helps sort the keepers from the culls. When used with replacement heifers, not only does it help determine who to sell in a drought-forced herd reduction, but also it ensures that the replacements that go into the herd are very fertile and will be highly functional and productive cows through their lifetime. In other words, it sets a solid base of females to rebuild a cow herd from, once the drought is broken.
Once early ultrasound-based pregnancy detection is complete in heifers, those that did not breed up essentially become stockers that can be marketed as feeders. Another option with these open heifers is to retain ownership to slaughter. Producers that have used this approach in recent years have found this to be a profitable approach vs. sale of excess heifers calves at weaning.
A wide variety of estrus synchronization protocols are available for both cows and heifers. The Beef Reproduction Task Force provides a list of recommended protocols and other useful tools and information at http://beefrepro.unl.edu/resources.html. There are a wide range of protocols to choose from that provide a range of how tightly estrus is synchronized. Some of these are effective enough that cattle can be time bred (artificially inseminated at a specific time) without detecting heat, while there are others that will synchronize estrus more loosely so they are suitable to use with natural service, allowing bulls to “keep up”.
In closing, shortening and tightening the breeding season can be effective at improving the fertility of the cow herd, so embarking on such a path can have benefits, even if the drought breaks and it is not needed as a tool to determine who to cull.