Performance of Barrow and Gilt Littermate Pairs at the Ohio Swine Evaluation Station

Abstract

Data used in this study were obtained from the Ohio Swine Evaluation Station. Records from 5 seasons (1954 fall through 1956 fall) on 385 full sib pairs (barrow and gilt) were used in these analyses. Starting at 63 days of age the pigs of a pair from a litter were fed together and taken off test individually as each pig reached 210 lb. live weight. The ration fed from the time pigs were 63 days of age until they reached approximately 120 lb. was calculated to contain 15.5% crude protein and that fed from 120 lb. to 210 lb., 13.6% crude protein. Rate of gain from 63 days of age to 210 lb., measurements of backfat thickness, carcass length, loin eye area (taken at the 10th rib), weights of the trimmed loin and the skinned ham, per cent of lean cuts of chilled carcass weight, and per cent of primal cuts of live weight were secured. Gilts averaged 7 days older than the barrows at 210 lb. Gilts had 0.1 inch less backfat, 0.51 square inch larger loin eye area, 1.08 lb. heavier loins, and 1.64 lb. heavier hams. Barrow carcasses yielded 2.3% less lean cuts of chilled carcass weight than did gilt carcasses. Positive correlations for loin eye area with primal cut yield of live weight of . 57 and . 56 were obtained for barrows and gilts respectively. Pounds of ham had a positive correlation with loin eye area of .60 and .54, respectively, for barrows and gilts. A negative correlation was obtained for backfat measurements with primal cut yield of .44 for gilts and .48 for barrows. All correlation coefficients reported here were significantly different at the 1% level for barrows and gilts.