Blind Estrous Synchronization in Suckler Cows and Beef Heifers.
On a farm visit in County Tyrone. A client presented suckler cows for estrous synchronization and pregnancy diagnosis. He had synchronized estrous for the purposes of using a fixed time A.I. Programme and then use a sweeper bull to catch the repeats. The pregnancy rate to fixed time A.I. was 18% this was explained by the fact that many of the heifers were in a deep pre-pubertal stage, the cows were in anoestrus.
The message I give here is cows and heifers need to be fit if estrous synchronization is going to yield satisfactory results.