Nutrient utilization by sheep and performance and carcass characteristics of steers fed crab waste-straw silage.

Abstract

Crab waste preserved with .2% NaOCl was mixed with wheat straw, liquid molasses, and water (32:32:16:20, wet basis) and ensiled for a minimum of 8 wk with microbial inoculant. A reduction in pH and water-soluble carbohydrates (WSC) and a higher concentration of lactic acid (4.9%, DM basis) were achieved. The trimethylamine (TMA) concentration in the silage was 11.2 mg N/100 g. In a digestion trial, 18 crossbred wethers (43 kg) were fed three diets: 1) basal, 2) a 50:50 mixture, DM basis, of basal and crab waste-straw silage, and 3) 100% crab waste-straw silage. Apparent digestibility of DM, OM, CP, energy, NDF, ADF, cellulose, and hemicellulose decreased linearly (P < .01) with increased levels of crab waste-straw silage. Nitrogen retention increased linearly (P < .05) with level of crab waste-straw silage. Apparent absorption was higher (P < .01) and retention was positive (P < .05) for Ca, Mg, Na, K, Cu, and Fe for sheep fed the highest level of crab waste-straw silage. In a 108-d trial, 30 yearling steers were fed diets in which crab waste-straw silage was included in the diet at 0, 15, and 26%, DM basis. Average daily gain tended to be highest (linear effect, P < .15) and carcass weights were highest (linear effect, P < .05) for steers fed 26% crab waste-straw silage. Average carcass quality grade was low Choice, and yield grade averaged 2.3, with no significant differences among treatments. Consumption of crab waste-straw silage did not adversely affect the taste of the meat. Results indicate that feeding crab waste-straw silage did not adversely affect nutrient utilization or performance of ruminants.