Processing of slaughterhouse blood and poultry litter and the effects on nutrient digestibility by steers

Abstract

Blood collected from a slaughterhouse was fermented with 10, 15 and 20% liquid molasses, and stored aerobically for 28 days. Blood treated with 20% molasses showed the lowest pH and residual water-soluble carbohydrates, indicating that fermentation was achieved. In each period of a digestibility trial. 451 of blood were preserved with 20% molasses for 14 days prior to feeding. The preserved blood had a sweet smell and an average pH of 4.07. Poultry litter was collected and deepstacked for a minimum of 3 weeks. The deepstacked litter had a pH of 7.1 and an acceptable aroma. Six Holstein steers were randomly assigned to a 6 × 6 Latin square design. The steers were fed wheat-straw based diets alone or with poultry litter, fermented blood (FB), blood meal or diets containing a combination of litter and processed blood. Apparent digestibility, measured by acid-insoluble ash (AIA) indicator and total collection of feces (TC) was highest ( P < 0.01) with steers fed the diet containing FB alone for dry matter (DM), organic matter (OM), crude protein (CP) and energy. Crude protein digestibility was higher for the diet containing a combination of blood meal and poultry litter compared with the diet containing only blood meal. Ruminal NH 3-N and blood urea-N were highest for steers fed diets containing straw plus poultry litter, and straw plus litter and FB. The amino acid content of the FB was improved compared with the blood meal. This study indicates that protein in FB was readily available and improves nutrient digestibility, and combining of blood meal and poultry litter provides the ruminal NH 3-N needed by the microbes for increased digestibilities.