Publication Date


Advisor(s) - Committee Chair

Jodie Pennington, Alvin Bedel, Gordon Jones

Degree Program

Department of Agriculture

Degree Type

Master of Science


Previous studies of dairy cattle have indicated that heifers and cows in hot, cold and moderate weather had different patterns of sexual activities. The purpose of this study was to compare distribution of sexual activities within estrus of dairy cattle. Three groups of lactating cows in hot, cold and moderate weather and a group of heifers in cold weather were observed. Estrus for each individual was divided into 12 equal periods. Sexual activities for 3 and 6 hours before and after estrus were also observed. The numbers of mounts and distribution of total sexual activities was analyzed. Mounts received per animal per period for all four groups were significantly different. Heifers had significantly more mounts than cows with 5.8 mounts per animal per period. Cows in hot weather had significantly less mounts than other groups with 1.2 mounts per animal per group. Cows in cold and moderate weather had similar numbers of mounts with 2.9 and 2.4 mounts per animal per period, respectively. This was significantly fewer mounts than were received by heifers but a significantly higher number of mounts than received by cows in hot weather.

There was much individual variation; however, the distribution of mounts and activities per period did not significantly differ across groups. There were trends for cows in hot weather to have rest periods within estrus where less mounting occurred. Secondary sexual activities before and after standing estrus were less intense than during estrus. Secondary sexual activities were greater in the three hours before and after estrus compared to the three to six hours before and after estrus.


Agriculture | Animal Sciences | Biology | Dairy Science | Life Sciences