Cow body condition at calving is the most important factor in determining how quickly a cow will breed back after calving, says Rick Rasby, University of Nebraska beef cattle specialist. “Some producers feel that if cows are thin at calving, then ‘flushing’ (feeding a high level of energy) the cow after calving will compensate for poor condition and result in acceptable breed back.”
This management practice works in limited situations. In most cases, extra energy after calving will stimulate milk production and not result in replenishment of energy reserves that seems to be necessary to signal the reproductive axis to “gear up” and assure acceptable reproductive performance. Trying to play catch-up after calving is almost always expensive because extra energy is needed in the diet.
Research conducted at Oklahoma State University was designed to either intentionally feed a group of first-calf heifers to achieve a body-condition score less than 5 (thin) by calving or a comparable group of heifers were fed to achieve a condition score of 5 and above by calving. After calving, half of each group was fed to either maintain the same level of condition while the other half of the heifers were fed to gain condition after calving.
The nutritional (both protein and energy) needs of the young cow during her first lactation are high. Because the young cow has a small rumen compared to mature cows, the quality of the diet needs to be high. Feeding medium-quality hays without supplementation is not an option.
“Target high-quality forages toward young females before and after calving. After calving, I think producers do a good job of meeting the young female’s protein requirement but many times fall short of meeting her energy requirement,” points out Dr. Rasby.
A combination of medium- to high-quality hays will meet the energy needs of mature cows after calving, but not young lactating females. It will be necessary to supplement energy in the young cows’ diets after calving with 3 to 4 pounds per head per day of an energy feed (corn, grain co-products, energy cube, etc.) or an equivalent of corn silage. For more information, go to http://beef.unl.edu/index.shtml