With proper planning and execution, using estrous synchronization and timed artificial insemination (TAI) can result in tighter calving seasons and higher returns to a cow-calf operation. To illustrate the concept, University of Florida researcher Cliff Lamb recently presented a real-world case study, and related research, during the 2016 Range Beef Cow Symposium in Colorado.
Lamb acknowledges that the complexity of synchronization protocols, need for specialized facilities, time and labor can discourage some ranchers from adopting TAI, but he says ranchers who make the change can capitalize on long-term economic benefits. As a real-life example, he describes how TAI has affected the 300-cow research herd at the North Florida Research and Education Center near Marianna, Florida. When Lamb began work at the center in 2006, the herd had a 120-day breeding season with natural bull service. Beginning in 2008, he set a goal of reducing the breeding season to 70 days within four years, while also improving pregnancy and calving rates. In addition to adopting estrous synchronization and TAI for heifers and cows, Lamb set several selection criteria to help achieve his goals. These are:
· Replacement heifers must become pregnant within the first 25 days of the breeding season. To help achieve this, the team bred 90 heifers with plans to keep 60.
· Every cow would be exposed to ES and TAI.
· Every cow must produce a live calf every year without assistance or she would be culled.
· Every cow must provide the resources for the calf to reach its genetic potential and her calf must perform well.
· Every cow must maintain acceptable body condition without supplemental feeding.
· Any cow with a poor disposition is culled.
In the first year, the team inseminated all heifers at day 1 and cows on day 8. They then bred a group of late-calving cows on day 49 and a group of “late, late” cows on day 70, and removed clean-up bulls on day 110.
In 2009, they used a similar process but were able to remove the bulls by day 88.
In 2010 they bred all late-calving cows on day 49 and removed the bulls on day 80, and in 2011 they used a similar system and removed the bulls on day 75.
By 2012, they had eliminated the AI service for late-calving cows. They bred all heifers on day 1, all cows on day 8, and removed the bulls on day 70.
Through this process, pregnancy rates were improved from around 82 in 2008 percent to 92 percent in 2012, while the breeding season was shortened by 50 days. With most females calving early in the season, weaning weights and calf values increased by $169 per calf. Across the 300-cow operation that translated to increased annual revenue of $50,700.
When the process began, Lamb says, the center’s crew were not anxious to make the change, perceiving TAI as additional labor. Once the system was it place though, they found the tighter breeding and calving seasons desirable.
Lamb notes that producers can use the “AI Cowculator” app, which he helped develop, to make more informed decisions in comparing the economics of AI versus natural service in their operations. The app, developed at the University of Florida with support from Zoetis, uses actual producer inputs and predicted cattle values to generate a partial budget to determine the gain or loss per cow if artificial insemination were to replace natural service.