Comparison of two doses of oestradiol benzoate administered at a resynchronised oestrus on reproductive performance of dairy cows

Abstract

OBJECTIVE: To compare the effects of two doses of oestradiol benzoate (ODB) administered as part of a treatment designed to resynchronise returns to oestrus on the reproductive performance of cows in a controlled breeding program. DESIGN: Cohort study. PROCEDURE: Lactating dairy cows on two farms were treated to synchronise three successive oestrous cycles. An intravaginal progesterone releasing insert (IVP4) was used to synchronise the first oestrous cycle. The cows were then treated 15 days after the first treatment by reinsertion of an IVP4 that had been used to synchronise the first oestrus and administration of 1.0 mg of oestradiol benzoate (ODB) i.m. at device insertion. The IVP4 devic..