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Protein and energy supplements in range beef production systems
Abstract
Protein and energy supplements are often required to achieve optimal production efficiency in range beef production systems. A series of experiments evaluated the use of protein and energy supplements in multiple beef production systems. Spring calving cows were used to evaluate the influence of supplemental protein prepartum and grazing sub-irrigated meadow postpartum on pregnancy rates and calf feedlot performance. Feeding supplement prepartum did not affect pregnancy rate but calves born to cows fed supplement were heavier at weaning. Allowing cows to graze subirrigated meadow improved body condition score pre-breeding and calf weaning weight but did not affect pregnancy rate. Feedlot performance and carcass weight were not affected by either prepartum or postpartum treatment. Spring-calving, crossbred heifers were used to compare two wintering systems. The control treatment included native range, supplement and hay. The treatment system relied on grazing and dried distillers grains based supplement. Heifers in the treatment system were heavier, had greater BCS at end of supplementation and heavier calves at birth and weaning but subsequent pregnancy rates were similar between systems. The treatment system cost $8.16/heifer less than the control. Three experiments evaluated the influence of dried distillers grains supplementation frequency on forage digestibility and growth of yearlings. Diet digestibility decreased as dried distillers grains supplementation frequency decreased and heifers and steers fed dried distillers grains more frequently has greater average daily gain. Two experiments evaluated supplemental degraded intake protein requirements when dried distillers grains were fed in excess of metabolizable protein requirements. Base diets were formulated to be greater than 100 g/d deficient in degradable intake protein. In both experiments, no response in performance was observed when degradable intake protein was added to the diet. Sufficient endogenously produced urea was probably recycled to correct the degradable intake protein deficiency. Adding urea is not necessary when dried distillers grains are fed in excess of the metabolizable protein requirement in forage based diets.
Subject Area
Livestock
Recommended Citation
Stalker, L. Aaron, "Protein and energy supplements in range beef production systems" (2005). ETD collection for University of Nebraska-Lincoln. AAI3186883.
https://digitalcommons.unl.edu/dissertations/AAI3186883