Animal Science, Department of


Date of this Version



Published in 2009 Nebraska Beef Cattle Report (Lincoln, NE: December, 2008). Copyright © 2008 The Board of Regents of the University of Nebraska.


Calving records collected between 2000 and 2008 at the Gudmundsen Sandhills Laboratory, Whitman, Neb., were used to determine the effect of estrous synchronization on calving distribution and the impact of time of calving on carcass characteristics. More synchronized cows calved during the first 21 days compared to non-synchronized cows, and calves born to synchronized dams were heavier at weaning. Calves born in the first 21 days of the calving season had greater carcass weights, marblingscores, and yield grades than later born calves. In addition, the percentage of steers grading premium choice or greater and the total carcass value declined as time of calving increased. Estrous synchronization with natural breeding resulted in cows giving birth earlier, and calves born earlier in the season were heavier at weaning and produced a heavier, more valuable carcass.