The Effect of Level of Protein Fed Baby Pigs

Abstract

The influence exhibited by the level of protein in rations fed baby pigs from two days to 7 or 8 weeks of age was studied, using rate of growth, feed utilization, nitrogen retention and levels of certain blood components as criteria of response. As the level of protein in the ration was increased from 15 to 41%, the kilograms of dry matter required per kilogram of gain decreased from 1.2 to 0.8; plasma tryptophan increased from 12 to 16 µg milliliter. Plasma protein, hemoglobin and blood nicotinic acid levels were not significantly altered. Efficiency of conversion of dry matter to body weight showed a negative correlation with age. The biological value of casein decreased as the level of protein in the ration was increased and as the pigs increased in body weight. It appears that the level of protein needed for maximum feed utilization and growth by baby pigs decreases as their body weight increases. The ration containing 41% protein produced maximum weight gains and feed efficiency for the very young pigs. As the pigs approached 8 weeks of age, a level of 20% protein appeared to be used as efficiently as higher levels.