ANSC 2120 Lecture Notes - Lecture 25: B Vitamins, Rumen, Lysine

• School: Cornell University
• Department: Animal Science
• Course: ANSC 2120
• Professor: Debbie Cherney

Document Summary

Lecture 25: meeting nutrient requirements for animal production and health (cid:1) (cid:1) General considerations: practical nutrition is an inexact science because: Ncr and other tables of animal requirements and feed composition are approximations only: they"re constantly improving/changing over the years. Without prior knowledge, tables are needed to estimate requirements for : energy, protein, minerals and vitamins, special dietary factors (e. g. fiber) Nrc tables also include values for feed composition but whenever possible, actual feed analysis values should be used. Energy requirements: energy requirements are considered first because: All dietary constituents except minerals and water contain energy; energy (carbons) is in almost everything. Feed ingredients mostly fed to supply energy (e. g. corn, forages) accounts for most of the ration in terms of weight and cost. Tdn (total digestible nutrients: tdn = dcp + dnfe + dcf + 2. 25(dee) Traditional us energy unit but has several disadvantages, esp. for feeds varying widely in energy values (e. g. forages)