Nutritional Evaluation of Perennial Ryegrass Straw as a Forage Source for Ruminants: Effect of increasing concentration of Lolitrem B
Intake, Digestion, Physiological Responses, and Milk Production in Beef Cows
An experiment was conducted to evaluate perennial ryegrass straw as a forage source for ruminants. We evaluated the performance and production of 72 Angus × Hereford cows (539 ± 5 kg BW) consuming perennial ryegrass straw containing increasing lolitrem B during the last third of gestation. Cows were blocked by body condition score (BCS) and randomly assigned to one of three TRT. Cows were provided perennial ryegrass straw ad libitum and supplemented with SBM (0.1% BW; CP basis) to meet the estimated requirement for degradable intake protein. Mixtures of a L and H lolitrem B straw (467 and 2017 ppb, respectively) were used to formulate TRT diets: 100% L; 50% L:50% H; 100% H. Thirteen of 24 cows on the 100% H TRT exhibited signs of ryegrass staggers and were removed from the study; nevertheless, lolitrem B concentration did not influence pre- or post-calving weight or BCS change. These data suggest that feeding perennial ryegrass straw containing up to 1550 ppb lolitrem B does not adversely affect nutrient digestion or physiological response variables in steers. However, providing straw with a lolitrem B concentration of approximately 2000 ppb resulted in 54% of cows exhibiting signs of ryegrass staggers. These data suggest that blending of straws with a high (> 2000 ppb) and low (< 500 ppb) concentration of lolitrem B can be a successful management practice.
Fisher, M.J., D.W. Bohnert, C.J. Ackerman,
C.S. Schauer, T. Delcurto, A.M. Craig,E.S.
Vanzant, D.L. Harmon, and F.N. Schrick. 2004. Evaluation of Perennial ryegrass straw as a forage source for ruminants. J. Anim. Sci. 82:2175-2184.(DWB PDF#1)