Effects of ammoniation and processing of cotton straw as the sole source of roughage in complete feeds on ruman characteristics with Murrah buffaloes

Abstract

Experiments were conducted utilizing 4 fistulated male Murrah buffaloes ( Bos bubalis) in a latin square design with 4 diets: (1) complete feed (mash) with untreated ground cotton straw (GCS), (2) complete feed (pellet) with untreated GCS, (3) complete feed (mash) with anhydrous ammonia (HN 3)-treated GCS and (4) complete feed (pellet) with NH 3-treated GCS. Ground cotton straw ( Gossypium sp.) treated with NH 3 at a 3.5% level at room temperature and kept for 42 days. Diets 1 and 2 were supplemented with urea, 1.5% level, to make them isonitrogenous. Nitrogenous constituents, total volatile fatty acids (TVFA) and pH values were determined on strained rumen liquor (SRL) taken at different intervals after feeding. Both ammoniation and pelletization had a significant ( P < 0.01) effect on the concentrations of various nitrogen (N) fractions, TVFA and pH values of the SRL. The concentrations of total N, trichloroacetic acid (TCA) insoluble N, residual N and food and protozoal N were increased with NH 3 treatment and pelletization whereas a reverse trend was observed for ammonia N. Ammoniation and pelletization of GCS decreased the pH values of SRL with a corresponding increase in TVFA concentrations. The concentrations of all N fractions and TVFA were highest at 2 h post-feeding and then declined slowly up to 6 h post-feeding except for residual N which peaked at 4 h post-feeding. pH was lowest at 2 h post-feeding and increased slowly up to 6 h post-feeding. Ammoniation and pelletization improved the rate of fermentation and utilization of complete feeds with GCS as the sole source of roughage in Murrah Buffaloes.