IOWA Cattleman
Official publication of the Iowa Cattlemen’s Association Vol. 37, Num. 4, May 2011
In Sync
Grant Dewell, DVM, Veterinary Diagnostic and Production Animal Medicine, Iowa State University
Don’t worry this article is not about a teenage pop music group but the breeding program for next year’s calf crop. (For those of you not in the know, N’Sync was a popular band of the late 1990s.)
Synchronization programs have been a critical management tool for cattlemen that use Artificial Insemination (AI). However, the benefit of synchronizing estrus goes beyond just being able to AI cows. There are long term benefits to the calf crop that can make a synchronization program beneficial to bull bred herds also.
Three benefits
The first benefit is a condensing of the calving season. When we front load the breeding program with synchronization we will then front load the subsequent calving season. This can make the first 2-3 weeks of the calving season fairly intense but the remainder of the calving season will seem like a breeze.
If you use off-farm labor during calving you can consolidate your costs into a shorter time frame.
The downside of early intensive calving is that if something goes wrong it can really go wrong. Make sure you have the facilities to handle the activity and it may be beneficial to calve later in the year when the threat of a severe snow storm has abated.
Another benefit can be improved health of the calves in general. One of the biggest risks for calf diarrhea and summer pneumonia is having calves of various ages mixed together. The older calves will expose the younger calves to pathogens that their immune system cannot handle yet.
A synchronized herd will have more calves the same age and fewer calves in the tail end of the calving season. Condensing the age of calves to within 30-45 days compared to 60 or 90 days can improve the health of your calves.
Lastly you will have a financial benefit when you sell you calves. When your cow herd is synchronized you will be able to put together a bigger group of calves that are the same weight and age.
Buyers will typically pay more for a uniform group of calves. Additionally, if more of your calves are born early in the calving season you will see an increase in your weaning weights because your average age is going to be increased.
There are enough different synchronization programs available that you will be able to find one that will work for you management style. Check with your veterinarian or beef extension specialist if you need assistance in determining which program is best for you.
Traditional bull to cow ratios of 1:25 is sufficient even with synchronized cows. A study in Colorado several years ago demonstrated no difference in pregnancy rates between a 1:25(83%) versus a 1:16 (84%) bull female ratio with synchronized heifers for a 28 day breeding season.
One caveat: I would not expect yearling bulls to be a capable of breeding synchronized cows compared to mature bulls. Bulls should have a breeding soundness exam prior to the breeding season to make sure they will be capable of servicing a large proportion of cows at one time.