EFFECT OF MOLASSES-BASED LIQUID SUPPLEMENTS ON DIGESTIBILITY OF CREEPING BLUESTEM AND PERFORMANCE OF MATURE COWS ON WINTER RANGE

Poor quality of tropical range forage leads to excessive weight loss a nd poor reproductive performance of beef cows. This research measured 1) the digestibility by steers fed creeping bluestem (Schizachyrium sc oparium var. stoloniferum) diets supplemented with cane molasses (0 or 20% of diet DM) and(or) added CP (no added CP, urea, or soybean meal) and 2) the performance of mature cows grazing creeping bluestem range and supplemented with 1.6 kg/(cow . d) (DM basis) of either molasses- urea or molasses-cottonseed meal-urea, each containing 30% CP (DM basi s). Bluestem averaged 4.7% CP and 37.0% in vitro OM digestion. In the digestion trial, diets supplemented with molasses had greater (P <.01) apparent OM digestibility but lower (P <.01) apparent NDF, ADF, and h emicellulose digestibilities than diets not supplemented with molasses . Apparent OM digestibility of diets supplemented with soybean meal wa s greater (P <.05) than that of diets supplemented with urea but not d ifferent (P >.05) from the control. While grazing range, mature cows s upplemented with molasses-urea lost less (P <.05) body condition (-1.7 vs -1.3) than cows supplemented with molasses-cottonseed meal-urea. T reatment did not affect cow weight loss on range (P = .85) or pregnanc y rate (P = .51). Cows supplemented with molasses-urea tended to wean a heavier calf (P = .09). When fed at 1.6 kg/(cow . d) to mature cows grazing range, a molasses-based supplement containing urea was of equa l value to one containing a natural protein.