Growth and Carcass Characteristics of Market Pigs Fed Reduced Lysine Diets in Bedded Hoop Barns

This study compared growth performance and carcass characteristicsof finishing pigsfed reduced lysine diets in bedded hoop barns. The purpose of this study was to compare growth performance and carcass characteristics of market pigs fed reduced lysine diets in bedded hoop barns with the intended goal of improving intramuscular fat. Pens of finishing pigs housed in hoop barns at the ISU Western Research Farm,Castana,IA,were randomly assigned one of two dietary treatments. The first dietary treatment was a corn-soybean meal based finishing pig diet formulated to meet or exceed recommended standardized ileal digestible (SID) Lysine concentration. The second dietary treatment was also a corn-soybean meal based diet that was formulated to deliver 24% less SID Lysine. Pigs were fed for 80–110 days, with pig weight and feed disappearancebeing measured every 28d.Pigs were scanned using real time ultrasound at the end of the trial. Following harvest, a subset of loins were analyzed for quality attributes. Overall,pigs underfed lysine grew slower and less efficiently. There were no differences in loin quality caused by dietary treatment,although there was a trend for pigs underfed lysine to produce smaller loin muscles. Matching diet formulation with genetic potential is a sound strategy for maximizing lean growth in pigs. Underfeeding lysine to pigs with the genetic potential for high levels of lean-growth didnot result in improved loin quality