Nutritional value of anaerobically fermented beef cattle wastes as a feed ingredient for livestock: Growth and carcass traits of beef cattle and sheep fed fermentor biomass

Abstract

Three experiments were conducted to determine the effects of feeding anaerobically fermented livestock wastes on performance and carcass characteristics of cattle and sheep. In the first experiment, fermentor effluent (FE) or dried centrifiged biomass (DCB) was fed to ewes and rams for 105 days. Diets containing FE (∓ bentonite) were allowed to ensile for 21 days before feeding. Overall average daily gain (ADG) was not altered ( P > 0·05) except in ewes fed DCB adn rams fed DCB plus bentonite, in which ADG decreased in both treatments. Decreased feed intake was also observed in both groups. In the second experiment, steers (174 kg liveweight) fed FE daily (6·45% of diet dry matter) for 168 days had a 4% to 12% higher rate of dry matter ( P < 0·005) intake but gained 15% slower ( P < 0·10) than steers fed the positive or negative (no supplemental protein) control diets. Rates of gain were not different between steers fed supplemental or no supplemental protein in the diet. Carcass-quality traits or taste-panel evaluation of steaks from steers fed FE were not different from steers fed the control diet ( P > 0·05) In the third experiment, weight gains and feed intake of heifer calves (378 kg initial weight) over 126 days were not altered ( P > 0·05) by feeding FE or influent (diluted wastes before fermentation) or the control diet with or without supplemental protein. Carcass quality traits also were not altered by dietary treatment. Thus, it appears that FE can be fed to cattle and sheep, in certain circumstances, without altering animal performance; however, the response was not consistent in all experiments.