IRM Farm Program Producer Highlight: B. Hamilton, Shortening the Calving Season!

– Ben Crites, IRM Coordinator, University of Kentucky

The UK IRM team has developed the IRM Farm Program, which is designed to increase the use of production practices that favor high reproductive rates in the cowherd. This program is delivered through on-farm learning to demonstrate the benefits of implementing these production practices. This spring marks the beginning of the third year for the program. To date we have 97 producers from 35 counties participating in the program. The results from these producers have been promising and we look forward to continuing to work with these cooperator herds.

Of the 97 producers participating, Mr. Hamilton has been a part since the very beginning of the program, starting early in 2015. Mr. Hamilton resides in Bracken County and runs a small herd of Limousin-influenced cattle. Initially, Mr. Hamilton did not have a defined calving season and ultimately wanted a fall-calving season beginning mid-September. Our first step was to remove the bull from the cowherd until we wanted the breeding season to begin. This eliminated the possibility of having calves born in the spring of 2016.

In the first year of the program, the cows that calved in the spring of 2015 were held open until the fall breeding season. In 2015, only 56% of the cows calved in the desired window. Six “done” cows were sold in 2015 for various reasons that included: age, feet/leg problems, and not having a calf. Two open replacement heifers were purchased as well. Mr. Hamilton was also interested in the benefits of using estrous synchronization and AI. In the first breeding season in the program, 12 cows were bred using a timed-AI protocol. He had one late-calving cow that received a CIDR device to help move her up in the calving season. Half of the females conceived to the AI, 12 of the 13 cows had and weaned a calf, and 100% of the herd calved in the desired window. The calving season took place in a 60-day window, beginning September 9^th and ending on November 11^th. When we look at the increase in weaning weight per cow exposed to the bull, from 2015 to 2016, an increase of 88 pounds (311 lbs to 399 lbs) was observed. Using the current market value (average of steer and heifer) for a 300 lb calf ($155/cwt) and 400 lb calf ($146/cwt), this 88-pound increase equates to an additional revenue of $119 per cow.

In 2016, Mr. Hamilton added five replacement heifers, increasing his herd size to 18 total breeding age females. Pleased with the first year results, Mr. Hamilton wanted to implement estrous synchronization and AI again in the fall of 2016. Based upon the pregnancy diagnosis information from this spring, 17 of the 18 females were confirmed pregnant and 75% conceived AI. Two cows that calved in November 2015, received a CIDR device before being exposed to the bull. Pregnancy diagnosis indicated that both females will calve in mid-October this fall. The estimated calving season length for fall 2017 is anticipated to be only 36 days based upon the pregnancy diagnosis. The results from Mr. Hamilton’s operation over the last two years are depicted in the table below.

In summary, the calving season length was shortened from 342 days to 60 days, to now an expected 36 days. This reduction in calving season length was possible through controlling exposure to the bull and also implementing an estrous synchronization program and AI. By reducing the length of the calving season we noticed an 88-pound increase in weaning weight per cow exposed, which equals an increase of $119 per cow with today’s market value. The results from Mr. Hamilton’s operation over the last two years are very encouraging and we are looking forward to see what the future has in store.