Nutrient Characterization of Swine Fecal Waste and Utilization of these Nutrients by Swine

Abstract

Swine feces from finishing hogs were fed in two metabolism trials by substituting for 21.7 and 37.3% (dry matter) of a basal corn-soybean meal ration. Unprocessed feces (fresh) were used in one trial and dried feces were used in the other trial. Feces collected from gilts fed rations containing feces had significantly higher levels of crude fiber, ether extract and gross energy, and significantly lower levels of crude protein and true protein than feces collected from gilts fed the basal ration. The fecal concentration of ash, NFE and nonprotein nitrogen tended to remain constant as percent of feces inceased in the ration. The fecal concentration of amino acids in most cases decreased as feces were substituted. Although the intake of all minerals increased as the percent of feces increased in the ration, only the fecal concentration of magnesium, copper and zinc were significantly higher with the concentrations of calcium, phosphorus and potassium remaining about constant. Phosphorus was the only urinary component which significantly increased as the level of feces substituted in the basal ration increased. Output of feces increased as the amount of feces substituted for the basal ration was increased with no differences in urinary output. Swine feces were found to be of less nutritive value than a basal corn-soybean meal ration. Digestibilities for dry matter, energy, ash, crude fiber, ether extract, crude protein, true protein and nitrogen-free extract, calculated by difference using the percentage of that nutrient which was from feces, were: 48.0, 46.7, 31.6, 40.9, 54.1, 60.1, 51.4 and 45.9%, respectively. With the exception of serine, glycine and cystine, in which the digestion coefficients were lower, the digestibilities of the other amino acids ranged from 51.2 to 65.1%. The apparent absorption of most minerals analyzed was reduced as the level of dietary feces substituted increased (the intake of all minerals increased as feces substituted increased), but absorption and retention, in grams per day, were similar or greater as feces were substituted for the basal ration. Copyright © 1977. American Society of Animal Science . Copyright 1977 by American Society of Animal Science.