The nutritional program you use for first-calf heifers can influence the long-term productivity of those heifers over the years they spend in your breeding herd.

Conventional nutritional programs for pregnant beef heifers usually provide
continuous levels of energy throughout pregnancy, and in many cases provide energy beyond the animals' requirements to assure adequate body condition by calving.


Researchers at North Dakota State University recently conducted a study to
determine growth and maternal responses of pregnant beef heifers developed on a nutritional program using energy restriction followed by an increased energy intake as they neared calving.

The researchers began their test 200 days before calving, using two different energy levels in the diet. Half of the heifers received constant dietary energy for a target gain of 1.2 pounds per day through calving. The other half were on a weight-cycle (WC) feeding program, receiving a restricted energy diet, 65 percent of the constant group, for either 90 or 120 days. The researchers then moved the WC groups to a higher-energy, limit-fed ration for the remaining time until calving. By design, the WC calves had lower gains and lower body-condition scores during the restriction phase, but they compensated once placed on the higher-energy diet and achieved similar body condition as the constant-energy group by calving.

Weight-cycled heifers had increased conception rates during the first 45 days of breeding season, compared with the constant-energy group. The researchers conclude that the weight-cycle feeding program can improve growth efficiency while avoiding excessive fleshing in first-calf heifers. This management strategy, they add, could minimize negative associative effects such as high birth weights, dystocia or lactation suppression that occur when feeding heifers energy in excess of requirements during late gestation. For the complete research report, got to: www.ag.ndsu.nodak.edu/carringt/livestock/01%20Beef%20Report.pdf