Effects of lucerne particle size and source of dietary carbohydrates on in situ degradation and ruminal variables in sheep

摘要

The effects of altering forage particle size and source of rapidly degradable carbohydrates on in situ degradation and ruminal variables were studied in four Iranian male sheep. The study was designed as a Latin square with a 2 × 2 factorial arrangement of treatments including two carbohydrate sources (pelleted beet pulp vs. maize- and barley-based concentrate) and two lucerne particle sizes (2.38 vs. 0.94 mm). Kinetics of disappearance of lucerne, concentrates and mixed samples was studied in situ . Among feed samples, the degradation rate constant of lucerne dry matter was higher ( P P = 0.06) in diets with reduced particle size. The rapidly degradable fraction of lucerne samples was also affected by treatments. Other degradability components were not affected. The mean ruminal pH was lower in diets containing short hay than in those containing long hay (5.76 vs. 5.86, P