| Animal by-products, such as meat and bone meal (MBM), contain high levels of amino acids, Ca, P, and B-vitamins and they are often included in swine and poultry diets. Meat meal and MBM differ in the composition of nutrients, especially Ca, P, and certain amino acids. This variation along with the different processing methods used during the rendering process can affect their nutritional value.; Eleven experiments were conducted to determine the digestibility, bioavailability, and nutritional value of MBM varying in processing for pigs and chicks. In five balance experiments involving pigs, the overall true digestibility of P in MBM was 80%, which was 90% of the true digestibility of P in monosodium phosphate (MSP). Particle size, ash content, and processing pressure of MBM did not affect P balance.; Five experiments were conducted to determine the relative bioavailability of P in MBM to that in MSP for growing pigs and chicks. In pigs, the P bioavailability estimates of MBM varying in ash content, particle size, and processing pressure ranged from 72 to 94%. In the chick experiment, the estimates ranged from 73 to 90%. Ash content of MBM had more of an effect on P bioavailability in pigs then the other processing variables and particle size of MBM had the greatest effect in chicks.; Ileal digesta was obtained in four pig experiments and in the chick experiment. Supplementing a corn-soybean meal-based diet with MBM varying in processing had no consistent effects on the digestibility of amino acids when fed to pigs. In chicks, the ileal digestibility of most amino acids was not affected by particle size or processing pressure, but the values for the low-ash and blended MBM diets were lower than for the high-ash MBM.; To investigate the value of MBM as the sole source of supplemental Ca and P, finishing pigs were fed MBM or dicalcium phosphate-calcium carbonate supplemented diets. Pigs fed MBM supplemented diets had greater gains and improved feed efficiency compared with those fed dicalcium phosphate-calcium carbonate supplemented diets. Carcass characteristics and bone strength were unaffected by source of supplemental Ca and P. |
