In Venezuela pregnancy rates (PR) of beef first-calf cows are low (25-30%), mainly due to nutritional restrictions resulting in a long postpartum anestrus, specially in the first-calf cow. By-pass fat supplementation decreases the negative energy balance of the post-partum cow (Staples et al., 1998), improving the reproductive performance. Therefore, our objective was to test the effect of bypass fat supplementation as an strategy to decrease the negative energy balance in first-calf beef cows during the post-partum period.
