The key factors that affect the percentage of cows cycling at the start of breeding
Dr. Glenn Selk, Extension Cattle Specialist, Oklahoma State University
The most important factors that determine if and when a cow returns to cycling activity were reviewed by Dr. Jeff Stevenson of Kansas State University. Over the past 6 years, Kansas State scientists have used more than 2,200 beef cows in estrous synchronization studies. As a part of these studies they determined which cows were cycling before the start of the breeding season both before and after synchronization treatments. They then looked at the previous data about each cow and determined the major factors that determined the likelihood that she would have returned to heat by the start of the breeding season. The research indicated that three main factors were the most important determinants as to whether the cow would recycle before the breeding season began. Body condition, age of the cow, and the number of days since calving were the biggest influences on incidence of cycling activity before breeding. Cows ranged in body condition score from 1 (extremely emaciated) to 7 (very fleshy) .
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