The number of observations for each treatment and the number of social groups studied are in Table 1. A social group was the cows in estrus in the drylot or pasture at the same time. Groups were considered different when greater than one-half of the cows in the group changed. Number of cows in estrus (P < 0.001) and replicate (P = 0.06) influenced the number of mounts received per estrus, but number of mounts received per estrus was not influenced by confinement area (P =
0.50) or interactions (P > 0.16) among confinement area, number of estrous cows, or replicate. Number of mounts received increased as the number of cows in estrus increased. When only 1 cow was in estrus, she received 11.0 ± 6.2 mounts, and mounts increased (P < 0.06) to 30.9 ± 3.6 per estrus when 4 to 6 cows were in estrus (Figure 1). Seven or more cows in estrus received
more (P < 0.002) mounts per cow (50.4 ± 3.2) than when 4 to 6 cows were in estrus (30.9 ± 3.0). When only 1 cow was in estrus, 47% of the cows received between 2 and 10 mounts. More than 60% of cows received greater than 20 mounts when 2 or more cows were in estrus. When ≥7 cows were in estrus, 77% of the cows received greater than 30 mounts per estrus. Cows received more (P < 0.06) mounts per estrus in replicate 1 (34.2 ± 2.8 mounts) than in replicate 2 (25.7 ± 3.4 mounts).