Effect of Amino Acid Supplementation of Rations Containing Meat and Bone Scraps on Rate of Gain, Feed Conversion and Digestibility of Certain Ration Components for Growing-Finishing Swine

Three experiments were conducted with 234 crossbred pigs to determine the effects of lysine, methionine and tryptophan supplementation to rations containing 5 and 10% meat and bone scraps on rate of gain, feed conversion and digestibility of certain ration components of growing-finishing swine. In all three experiments the addition of amino acids to rations containing meat and bone scraps failed to give a significant increase in rate of gain. However, in most instances the addition of tryptophan did result in improved gain. The failure of amino acid supplementation other than trytophan to give a growth response appeared to be due to an amino acid imbalance. In experiments 1 and 3 average daily feed intake tended to decrease with the 10% MBS rations when lysine and methionine or combinations of these amino acids were added to the ration. Feed required per pound of gain was not affected by the treatments. Digestion studies using the chromic oxide indicator showed that dry matter, energy, and nitrogen digestibility tended to decrease as the number of amino acids supplemented was increased. Time of collection also appeared to be an influencing factor since dry matter, energy and nitrogen digestion coefficients tended to be higher in the morning than in the afternooon except for the collection made at 8 a.m. It is evident from these experiments that meat and bone scraps with or without amino acid supplementation do not improve a properly supplemented corn-soybean ration. However, meat and bone scraps can effectively replace part of the soybean meal as a protein supplement if a greater percent of total protein is used in the ration.