Cornell net carbohydrate and protein system for nutritional evaluation of tree leaves, shrubs and grasses

Abstract

Five species each of tree leaves, shrubs and grasses were nutritionally evaluated for their chemical constituents, carbohydrates, proteins and nitrogen fractions, following the Cornell net carbohydrate and protein system (CNCP). A summative approach was also used to derive the TDN (total digestible nutrient, (%DM) at IX maintenance) values of these feeds so that more realistic values can be obtained to decide their appropriate level of incorporation in total mixed ration of the ruminants. The CP varied from l2.27 to 21.79, 11.27 to 17.49 and 3.49 to 4.27% in tree leaves, shrubs and grasses, respectively. Among the tree leaves, CP was highest in Lellcaena leucocephala (21.79%) followed by Albizia lebbek (20.85%) and lowest in Anogeissus pendula (l7 .49%). In shrubs, the CP was maximum in Dichrostach.vs cinerea. Grasses were the richest in total carbohydrates compared to shrubs and tree leaves. Non-structural carbohydrate content varied greatly among the tree leaves, shrubs and grasses. Significantly lesser quantity of fraction C was present in Grewia optiva, Securengia virosa and Heteropogan contortus in tree leaves. shrubs and grasses respectively. The instantly degradable fraction A of nitrogen was higher in tree leaves followed by grasses and shrubs, whereas rapidly degradable fraction B1 was higher in grasses followed by shrubs and tree leaves. Among the tree leaves and shrubs, Grewia optiva, Leucaena leucocephala, Securengia virosa and Zizyphus xylophyrlts can be used as good sources of quality protein whereas, among the grasses, Heteropogan contortus and Diclzanthiwn annulatum are better energy sources to the ruminants. The TDN estimates (at 1*X level of maintenance) showed a significant (P