In Situ Ruminal Degradation Kinetics of Dry Matter, Crude Protein and Neutral Detergent Fiber of Tropical Ruminant Feedstuffs

The in situ ruminal degradation kinetics of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of nine common ruminant feeds (six concentrate feeds viz. maize grain (MG), groundnut cake (GNC), mustard oil cake (MOC), cotton seed cake (CSC), deoiled rice bran (DORB), wheat bran (WB) and three fodders viz. berseem fodder (BF), maize fodder (MF) and sorghum fodder (SF) was evaluated. Nylon bags with concentrate feeds in quadruplicate were incubated for 0, 2, 4, 8, 16, 24 and 48 h while those having fodders were incubated for 0, 2, 4, 8, 16, 24, 48 and 72 h in two adult rumen fistulated bulls. The non linear model of Ørskov and McDonald was used to interpret the data and to arrive at quickly degradable fraction (a), slowly degradable fraction (b), degradation rate (c) and effective degradability (ED) of test feeds. Effective DM degradability was highest in MOC among concentrate feeds and in BF among fodders. Similarly highest effective CP degradability was recorded in MOC and MF in test feed categories. GNC and MF showed highest effective NDF degradability among concentrates and fodders, respectively. It was concluded that DORB, CSC and BF due to their least CP degradability can be incorporated into dairy rations as feeds with higher bypass protein value while MOC and MF due to their higher NDF degradability can be considered as better fibre and energy source for ruminants.