Indian Journal of Science and Technology

Abstract

An experiment was conducted to predict the energy content (TDN- total digestible nutrients, DE- digestible energy and ME- metabolizable energy) of some commonly used tropical concentrate feeds of ruminants using the summative approach model of National Research Council (NRC) 2001, which is based on chemical composition values of feeds rather than the values of digestion trial. Fourteen concentrate feeds (six grains, three oilcakes, two protein meals, three agro-industrial byproducts) were analyzed for their proximate principles, fiber components, neutral detergent insoluble nitrogen (NDIN), acid detergent insoluble nitrogen (ADIN) and the TDN was then calculated. DE and ME contents were estimated from the TDN value. Three types of total mixed rations (TMRs) were prepared comprising 40% concentrate mixture, 40% green fodder (berseem- Trifolium alexandrinum) and 20% wheat straw (Triticum aestivum) on dry matter basis (DMB). These TMRs were fed to three groups of growing Sahiwal calves (average body weight of 173.66±12.54 kg and average age of 12 – 18 months). The predicted TDN values of the TMRs as per NRC (2001) were 60.21, 60.14 and 60.53% of DM, respectively. The TDN values obtained by the results of the digestion trial (61.11, 61.98 and 60.56%) were in conformity with that of in vitro results. Therefore, it was concluded that the TDN based model of NRC (2001) can be successfully implemented to predict the energy density of tropical ruminant feeds. The predicted TDN values of concentrate feeds were also more or less in close proximity of their standard TDN values.

Keywords: Energy Content, NRC- 2001 Model, Ruminants, TDN, Total Mixed Rations