Comparisons of specific crosses from Duroc-Landrace, Yorkshire-Landrace and Hampshire-Landrace sows managed in two types of gestation systems: pig performance.

Ten thousand one hundred sixty-nine pigs were farrowed in 844 litters that were produced by mating Duroc (D), Yorkshire (Y) and Hampshire (H) boars to Duroc-Landrace (DL), Yorkshire-Landrace (YL) and Hampshire-Landrace (HL) sows to study the effect of sire breed, dam breeding and gestation environment (pasture lots vs confinement stalls) on pig weights, survival rates and feed efficiency. Pigs sired by H boars were .05 kg heavier at birth than Y-sired pigs and .2 kg heavier at 21 d than Y- and D-sired pigs, but they were .6 kg smaller at 56 d. D-sired pigs grew .028 kg/d faster from 56 d to 100 kg and reached 100 kg approximately 5 d sooner than the Y- and the H-sired pigs. At birth, pigs out of DL sows were .21 kg heavier than pigs out of YL sows. Pigs out of HL sows grew .025 and .021 kg/d slower from 56 d to 100 kg compared with pigs out of DL and YL sows, respectively. Sows in the pasture gestation system produced pigs that were .05 kg heavier at birth than pigs out of sows in gestation stalls. Three-breed-cross pigs were .9 kg heavier at 56 d, grew .039 kg/d faster and took 7.9 fewer days to reach 100 kg than backcross pigs. The H sire breed had lower survival rates of pigs at 21 d and to 100 kg of those born alive (P less than .10), compared with pigs sired by D and Y boars. Pigs out of HL dams had the highest survival rates, whereas pigs out of YL sows had the lowest survival rates at birth, 21 d and at 100 kg. Three-breed-cross pigs averaged .025, .028 and .035 greater survival rates at birth, 21 d and 56 d than backcross pigs. Feed efficiency was most desirable in pens of pigs sired by H and D boars compared with pens of pigs sired by Y boars. However, pens of pigs with YL dams were more efficient than pens of pigs with HL dams.