Written collaboratively by Julie Walker, George Perry, Warren Rusche and Olivia Amundson.
Introduction
It has been understood for decades that reproductive performance is the most important aspect affecting production efficiency of a cow-calf enterprise. To maintain a calving interval of 365 days, a cow must re-breed in 80 to 85 days after calving. The priorities of nutrient utilization in a beef cow are: body maintenance, growth, lactation, fetal growth, breeding, and body reserve according to Short et al., (1990). The energy reserves of the beef cow at calving has been identified as the single most important factor affecting postpartum interval to estrus and re-breeding success in beef cows.