In situ ruminal and intestinal nutrient digestibilities of mesquite ( Prosopis juliflora) pods

Abstract

Two steers fitted with ruminal and duodenal cannulas were used in a randomized complete block design to determine ruminal and intestinal digestibility of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) from as collected and dried (80 °C for 2 h) mesquite pods. On a DM basis, as collected mesquite pods contained 290 g kg −1 neutral detergent fibre, 172 g kg −1 acid detergent fibre, and 127 g kg −1 CP. Drying at 80 °C for 2 h reduced ( P<0.05) the in situ soluble CP fraction and increased ( P<0.05) the slowly degradable CP fraction and its rate of degradation. However, ruminal degradability of both CP and DM of mesquite pods were not affected by drying. Post-ruminally digestibility of ruminal undegraded CP and NDF were low and unaffected by drying. Total tract digestibility of DM, CP and NDF were similar for as collected and dried mesquite pods, averaging 68, 78 and 9%, respectively. It was concluded that the rumen is the main site of digestion of mesquite pods and that drying at 80 °C for 2 h had no adverse effects on their intestinal or total tract digestibilities.