Evaluation of low quality roughages and agricultural by-products as livestock feed

Nine feeding trials and four laboratory scale experiments were conducted in this study. The study consisted of: (1) use of grass straw:corn juice (CJ) silages with fishmeal and/or alfalfa hay supplementation in beef heifers, sheep, pregnant dairy heifers, water buffaloes and Hereford cows; (2) use of cull onions:grass straw silages in sheep and their laboratory scale evaluation; and (3) evaluation of yucca extract (Deodorase) as a supplement in cattle and rabbits feeds for improving utilization of low-quality roughage-based diets. The straw:corn juice (CJ) silages proved to be similar to medium quality grass hay in terms of weight gain and feed efficiency (FE). Use of ammoniated straw:CJ silages proved even better than grass hay, and with fishmeal (FM) and/or alfalfa hay supplementation further improved their feeding value. Digestibility of ammoniated fescue straw:CJ silage was higher than grass hay in sheep. The digestibility of ryegrass straw:CJ silage was significantly higher in water buffaloes vs Hereford cows. In dairy heifers the FE of this silage plus 125 g FM per head per day (SA) was similar to grass hay and it was better in SA compared to simple silage (S). Post-partum milk production and composition did not differ among 3 treatments. In cull onions:grass straw silages (laboratory scale), use of 0.1% raw soybean (RSB) in urea treatment, significantly improved CP and OM content. In other two experiments, CP was significantly higher in straw:onion silages treated with 3% urea than non-treated straw:onion silages, and higher in 5% urea treated vs 3% urea treated silages. The IVDMD was significantly lower in control than 3% and 5% urea treated silages. Feeding of onion:straw silage to sheep resulted in weight loss and supplementation with alfalfa pellets did not stop weight loss, and blood packed cell volume decreased from 40% to 34% after feeding onion:straw silage. In cattle and rabbits diets, use of yucca extract (YE) improved weight gain and reduced rumen ammonia-N, plasma ammonia-N and plasma urea-N levels in most of the cases especially the feeds containing urea. (Abstract shortened by UMI.).