Abstract
Ninety-three pigs from lines within the Duroc and Yorkshire breeds which had been selected for high- and low-backfat thickness were fed either a 12 or 20% protein diet. Pigs were slaughtered at six ages between 84 and 224 days, and the amounts of lean, fat and bone in the carcasses were determined. Carcasses from Yorkshire and low-fat pigs had significantly more lean and less fat than did those from Duroc and high-fat ones. Carcasses from pigs fed 20% protein had significantly more lean but about equal weights of fat compared with those from pigs fed 12% protein. There was a significant line x diet interaction for weight of carcass lean. Low-fat pigs fed the 20% protein diet had an average of 21.4 kg. of lean in their carcasses compared to 16.3, 14.8 and 15.7 kg. for high-fat pigs fed 20% protein and high- and low-fat pigs fed 12% protein, respectively. Copyright © 1969. American Society of Animal Science. Copyright 1969 by American Society of Animal Science