Estrous synchronization can boost profits

May 15, 2010
by WLJ

Research demonstrates estrous synchronization in cows can improve calving distribution and progeny value.

Synchronizing estrous is a tool that can be used to concentrate when animals exhibit estrus and, potentially, calving distribution.

Calving records collected between 2000 and 2008 at the Gudmundsen Sandhills Laboratory near Whitman, NE, were used to determine the effect of estrous synchronization on calving distribution and the impact of time of calving on steer weaning, feedlot and carcass characteristics.

A major goal in estrous synchronization is to increase the percentage of calves born early in the calving season. University of Nebraska-Lincoln research found that calves born in the first 21 days of the calving season are heavier and more uniform at weaning and have greater carcass weights and quality grades.

Data were compared from 60-day, non-synchronized and 45-day, synchronized breeding seasons, both using natural breeding. Compared to the 60-day nonsynchronized season, 12 percent more calves were born in the first 21 days of the calving season, and the average weaning weight was 20 pounds greater for the 45-day synchronized breeding season.

The benefits don’t stop with weight at weaning, said Rick Funston, beef cattle reproductive physiologist at the West Central Research and Extension Center at North Platte.

“There are significant benefits to the cow,” Funston said. “It benefits the cow because she has a longer time to breed back. It gives the cow a longer period of time from calving to breeding, so the postpartum interval is lengthened.”

Shortened calving periods result in more efficient use of labor inputs for calving and vaccinations, and increased returns on feed inputs.

The synchronization system used was a single injection of prostaglandin F2alpha given five days after bull turn in and cost less than $2 per dose.

Funston does not recommend shortening the breeding season of the cow herd with this synchronization system the first year as late calving, non-cycling cows will not respond to this synchronization protocol and may need the additional days to become pregnant.

“The place to start is with replacement females, having a short first breeding season coupled with synchronization so they never are introduced into the herd as a late calver,” said Funston. “In a modest to low input heifer development system, a non-pregnant female at pregnancy diagnosis is generally a valuable commodity as a yearling.” — WLJ