Nutritional Evaluation of Perennial Ryegrass Straw as a Forage Source for Ruminants: Effect of increasing concentration of Lolitrem B
Nutritional Evaluation of Perennial Ryegrass Straw as a Forage Source for Ruminants: Effect of increasing concentration of Lolitrem B
Intake, Digestion, and Physiological Responses in Steers
An experiment was conducted to evaluate perennial ryegrass straw as a forage source for ruminants. We evaluated digestion and physiological variables in steers offered perennial ryegrass straw containing increasing levels of lolitrem B. Sixteen ruminally cannulated Angus × Hereford steers (231 ± 2 kg BW) were blocked by weight and assigned randomly to one of four treatments (TRT). Steers were provided perennial ryegrass straw at 120% of the previous 5-d average intake. Prior to straw feeding, soybean meal (SBM) was provided (0.1% BW; CP basis) to meet the estimated requirement for degradable intake protein. Low (L) and high (H) lolitrem B straws (<100 and 1550 ppb, respectively) were used to formulate TRT diets: 100% L; 67% L:33% H; 33% L:67% H; 100% H. Intake and digestibility of DM and OM, and ruminal pH, total VFA, and NH3-N were not affected by increasing lolitrem B concentration. Ruminal indigestible ADF (IADF) fill increased linearly (P = 0.01) and IADF passage rate decreased linearly (P = 0.04) as lolitrem B increased. 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.
gh (H) lolitrem B straws (<100 and 1550 ppb, respectively) were used to formulate TRT diets: 100% L; 67% L:33% H; 33% L:67% H; 100% H. Intake and digestibility of DM and OM, and ruminal pH, total VFA, and NH3-N were not affected by increasing lolitrem B concentration. Ruminal indigestible ADF (IADF) fill increased linearly (P = 0.01) and IADF passage rate decreased linearly (P = 0.04) as lolitrem B increased. 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.