Estimation of Metabolizable Energy, Net Energy-Lactation and Total Digestible Nutrients of Some Ruminant Feedstuffs Using In Vitro Gas Production Technique

Abstract

Nutritive values of available feedstuffs are fundamental for formulating rations at field level. The gas measuring technique has been widely used for evaluation of nutritive value of ruminant feedstuffs. A study was conducted to evaluate metabolizable energy (ME), net energy required for lactation (NEl) and total digestible nutrients (TDN) of some ruminant feedstuffs, by using in vitro gas production technique. The commonly available feed samples of concentrates (n=39) and roughages (n=10) were collected from different regions of the country. All the ground feed and fodder samples were analysed for crude protein (CP), ether extract (EE), crude fibre (CF), neutral detergent fibre, acid detergent fibre, total ash, acid insoluble ash, calcium and phosphorus. Average CP, EE and CF contents in compound cattle feed was 21.2, 2.8 and 11.8%, respectively. ME, NEl and TDN were estimated by incubating 200 mg of each of the samples with rumen mixed microbe inoculums for 24 hr period, taken from fistulated buffaloes. Amongst concentrate feeds, cottonseed cake (Gossypium spp.) had lowest ME (6.9 MJ/kg DM), NEl (3.6 MJ/kg DM) and TDN (47.1%) values, whereas, taramira seeds (Eruca sativa) had highest ME (14.6 MJ/kg DM), NEl (8.7 MJ/kg DM) and TDN (88.5%) values. Similarly, among roughages, methi straw (Trigonella foenum-graecum) had lowest and subabul leaves (Leucaena leucocephala) had highest ME (5.8 vs. 12.4 MJ/kg DM), NEl (2.7 vs. 4.7 MJ/kg DM) and TDN (41.5 vs. 76.5%) values. Chemical composition and energy values reported for various feed and fodders in this communication could be used for formulating ration of dairy animals under field conditions for better utilization of locally available feed resources.