Effect of Urea Treatment of Roughages and <i>in vitro</i> Digestibility of Available Feed Resources in Maradi Area of Niger

Abstract

The effect of urea treatment of roughages and the digestibility of feeds for ruminants was studied in southern Niger. Cereal straws, legume crop residues and concentrates were collected in the dry season. Cereal straws were millet stover, sorghum stover with its fractions (leaves and sheath, stems), Diheteropogon hagerupii, Eragrostis tremula and Schizachyrium exile and legume crop residues were groundnut haulms and cowpea husk. Cereal straws and cowpea husk were either untreated or treated with urea. In vitro digestibility characteristics were determined using rumen fluid from fistulated Jersey cows and metabolizable energy (ME) was determined through gas production after 24h of incubation. Cereal straws had different (P<0.001) apparent degradability (Apdeg), degradation rate (C), halflife to the maximum gas volume (T 1/2), degradation efficiency factor (DEF) and ME. Whereas, urea treated cereal straws had higher (P<0.001) (C) and increased (P<0.01) ME. Legume crop residues did not affect (P>0.05) in vitro parameters, however, treating cowpea husk decreased (P<0.05) gas production and (T 1/2) but increased ME (p<0.01). Concentrate degradation and kinetics parameters varied (P<0.001) strongly, while Apdeg and true degradability varied (P<0.01) leaving microbial yield (MY) unaffected. These findings will contribute to better utilization of the concerned feed resources by ruminants in Niger and related environment.