Studies on genetic and phenotypic parameters of growth and carcass traits in pigs raised in two different feeding regimes

For crossbred pigs, mainly derived from Large White and Landrace and with a small proportion of Berkshire inheritance, daily gain averaged 729±48.5 and 821±85.9 g on restricted and ad lib. feeding resp., daily feed intake 1.85±0.43 and 2.31±0.16 kg, feed conversion efficiency 2.56±0.15 and 2.85±0.31, P2 backfat thickness 15.3±1.90 and 16.8±2.43 mm and weight of lean in the ham 6.07±0.36 and 6.07±0.56 kg. Corresponding h²s were 0.399 and 0.307, 0.410 and 0.480, 0.403 and 0.129, 0.619 and 0.315, and 0.446 and 0.350. Genetic correlations between daily gain and feed conversion efficiency were -0.94 and -0.46 for restricted and ad lib. feeding resp., those between daily gain and weight of lean in the ham were 0.95 and 0.97, and those between feed conversion efficiency and weight of lean in the ham were -0.97 and 0.46.