Effect of ammonia treatment and processing of whole cotton plants as sole source of roughage in complete feeds for growing cross-bred calves

Abstract

The effect of anhydrous ammonia (NH 3) treatment and pelletization on the nutritive value of ground whole cotton plant (GWCP) as the sole source of roughage in complete feeds for growing cross-bred male calves was studied in a growth-cum-metabolic trial. The GWCP ( Gossypium sp.) was treated with NH 3 at 3.5% on a dry matter basis at room temperature in polyethylene bags and kept for 42 days. Twenty four cross-bred male calves (158 kg) were randomly allotted to the following four rations: 1. complete feed (mash) with untreated GWCP; 2. complete feed (pellet) with untreated GWCP; 3. complete feed (mash) with NH 3-treated GWCP and 4. complete feed (pellet) with NH 3-treated GWCP. Rations 1 and 2 were supplemented with urea at a 1.5% level to make the rations isonitrogenous. Ammoniation increased the crude protein content of GWCP from 7.8 to 16.0%. Voluntary intake of dry matter was improved ( P < 0.05) by ammoniation. Total digestible nutrients were improved ( P < 0.01) by ammoniation as well as pelletization. Digestibilities of neutral detergent fibre, acid detergent fibre, hemicellulose, cellulose and lignin were improved ( P < 0.01) by ammoniation but not affected by pelletization. Average daily gain was higher ( P < 0.01) in animals fed rations containing NH 3-treated GWCP than their corresponding mash pellet rations containing untreated GWCP. Dry matter consumption per kg live weight gain was highest with ration 1 and lowest with ration 4. Cost of feed per kg live weight gain was higher ( P < 0.01) in rations containing NH 3-treated GWCP. These results suggest that GWCP could be utilized as the sole source of roughage in complete feeds of cattle. NH 3-treatment of GWCP and pelletization of the complete feeds containing GWCP improved the utilization of GWCP.