We turned a bull with our 16 heifers in November when they were around 15 months old. They had been riding each other like crazy before he came, so I figured the bull would have a stroke within the first week; however, he was greeted rather calmly. The herd is in the pasture around my house, but I work during the day, so I don't get to view them all the time. Oddly, however, I have yet to see any action other than the the bull sniffing around and the heifers continuing to ride each other, which I saw today. The bull is borrowed from a friend, so he is fertile. How long would it typically take for a bull to breed 16 heifers? Do heifers exhibit behaviors different to older cows when it comes to being bred?