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 173.66ยฑ12.54 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.
Highlights
Energy content of a feed is the most important criteria in determining its feeding value in ruminants
The data pertaining to TDN values of tropical feeds available is still based on the proximate analysis and in vivo digestibility studies[7]
There was provision for a correction factor in the form of metabolic faecal TDN from the summative values of truly digestible nutrients, which makes the model logical and scientific. This model was accepted by NRC8 for evaluating feed TDN values and the energy values of DE and ME were estimated from the equations of NRC12
Summary
Energy content of a feed is the most important criteria in determining its feeding value in ruminants. With emergence of sophisticated ruminant nutrition models like NRC8, AFRC9, CNCPS10 the feed analytical techniques have improved manifold, several prediction equations have come up for predicting the energy values of ruminant feeds One of such prediction model to calculate the TDN values of feeds was developed by Weiss et al.[11] which included both proximate and detergent system of feed analysis. There was provision for a correction factor in the form of metabolic faecal TDN from the summative values of truly digestible nutrients, which makes the model logical and scientific This model was accepted by NRC8 for evaluating feed TDN values and the energy values of DE and ME were estimated from the equations of NRC12. This study is, aimed at predicting the TDN values of some common concentrate feeds using the prediction equations of NRC8 and to validate these equations by comparing the predicted values with that obtained by digestion trial
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
