Spring calving season should be wrapping up soon for most cow calf operations and the attention will soon be turned to preparing for next spring's calving season. The first step in that preparation is to get the cows pregnant again.
Whether a bull breeds your herd or you utilize artificial insemination or even embryo transfer, there are a few things to consider right now as you prepare to get the cows bred.
Second, make sure the cows are ready for the bull. This involves more than just providing adequate nutrition and minerals, although those are very important. Once all of the calves are on the ground, it is a good time to vaccinate the cow herd with a modified live (MLV) 10 way respiratory vaccine containing 5 strains of Lepto. Do not use these MLV vaccines on pregnant cows, though, as they can induce abortion in naïve cattle.
If you want a tight calving season next year, you need to have all your cows cycling again soon after delivering their calves. Cows with nursing calves are notoriously slow to cycle because of the effects of the calf. Every time the calf nurses, the action of suckling induces the cow to let her milk down which is achieved by the action of the hormone oxytocin.
A secondary effect of the oxytocin is to prevent the cow from resuming her normal estrous cycle, sometimes for several months.
We can fool the cow into thinking it's time to breed again by simply interrupting the oxytocin release for about 36 hours or so. To do this, you have to separate the calves from the cows for 36 hours. They will bawl and bawl, so you might want to warn the neighbors. Offer the calves some clean water and nice soft second crop hay and they will be fine for the short time that the cow needs.
This separation will often induce an ovulation and the cows will be displaying estrus behavior within 2 to 3 weeks. After the separation, the cows will find their own calves and all will be right in their world again.
This can be done either to a group of cows or individuals. This is a trick I use periodically to get an embryo donor to cycle in time to be flushed and bred back again for the next calving season. Donor cows don't respond to stimulation drugs unless they have already gone through a cycle and removing the calf will induce her to cycle. We have done this successfully in cows with calves as young as 45 days old.
We've also used this trick to induce cycling in cows to be synchronized for artificial insemination and embryo recipients. You want to remove the calves at least two weeks before starting the synchronization protocol in both brood cows and recipients. That will give enough time for the first ovulation to occur before setting up the synchronization program.
Speaking of synchronization programs, there have been some great advancements with protocols over the last few years. The main drawback to systematic timed breeding in beef cattle is number of times they have to go through the chute for injections. The original Pre-Synch protocol took about 38 days and six trips through the chute. Recent advancements have shortened that to as little as eight days and three trips through the chute. One recently developed protocol called five day CO-Synch plus CIDR can be completed in eight days and has shown superior conception rates to older, more established synchronization protocols.
These protocols require prescription drugs and, as such, I cannot recommend them in this format, so ask your herd veterinarian about them.
Getting beef cattle bred back quickly can help tighten your calving season leading to a more uniform group of calves. Increasing the number of calves you wean by improving reproductive efficiency can have a huge impact on your bottom line. In the current beef market, a little extra attention to detail can dramatically increase revenue from calves. Plan today for a big payoff next year.