NUTRITIONAL EVALUATION OF DEHYDRATED CATTLE MANURE USING SHEEP
Manure from a commercial feedlot was dehydrated at an alfalfa dehydration plant. The manure contained, on a dry matter (DM) basis, 14.8% crude protein, 14% ash, 0.83% calcium, 0.69% phosphorus, 30.5% crude fiber, and 2.6% fat. About 45% of the DM in the manure was wheat straw bedding. Each of three pelleted rations: 50% hay 50% barley (HB); 50% manure 50% barley (MB); and 100% manure (M) was fed ad libitum to eight individually penned yearling wethers in a 38-day feeding trial. In addition to the manure pellets, lambs on ration M were fed 200 g/day alfalfa hay until intake of pellets exceeded 600 g/day, and 200 g/day barley during the first 28 days on test. A digestibility trial, five wethers per treatment, was conducted after the 38-day feeding trial. Mean daily DM intake during the feeding trial was 2,054, 1,714, 1,165 (pellets only) g and mean daily gain was 272, 148 and −57 g for rations HB, MB, and M, respectively. The corresponding values were 2,632, 2,277, and 2,050 g for DM intake during the final 10 days of the feeding trial, 62.7, 51.7, and 26.7% for DM digestibility, and 70.9, 62.6, and 42.2 for nitrogen digestibility. Molar percent volatile fatty acids in rumen fluid of lambs on ration M were similar to those normally observed for high roughage rations. Molar percent acetic in rumen fluid of lambs on ration HB was greater (P < 0.05) and percent valeric lower (P < 0.05) than on ration MB. It was concluded that sheep will consume rations containing large amounts of dehydrated manure, but low digestibility of manure severely limits its value as a ration ingredient.