Production trait comparison of five pig sire lines with different halothane genotypes

Production traits of terminal products from five sire lines were compared. The sire lines were Hampshire x Duroc (HD, 28 sires), Duroc (DD, 28 sires), Large White x Duroc (YD, 31 sires) from the National Danish breeding programme, Large White x Duroc (KRUSTA, 20 sires)from Stamboek International and BIC 416 (19 sires) from PIG. Semen from these five lines was used in a balanced scheme in four production herds with Landrace x Large White sows. About 100 litters from each line were produced, and from each litter one gilt and one castrate were selected at weaning and shipped to an early weaning unit, then to test stations, and tested from 30 kg to 115 kg live weight. Pair-wise comparisons of lines were made, and P-values were adjusted for multiple comparisons. Daily gain (g day(-1)), feed conversion (kg feed/kg gain) and lean percentage of offspring from HD, DD, YD, KRUSTA, and PIC 416 adjusted for halothane genotypes were (933, 952, 942, 944, and 924), (2.84, 2.80, 2.84, 2.99, and 2.92), (58.6, 58.3, 58.5, 57.4, and 58.5). The differences in daily gain were not significant. KRUSTA had significantly lower lean content than all the other lines. KRUSTA and PIC 416 had significantly poorer feed conversion than HD, DD and YD. Sires from PIC 416 were all carriers of the halothane gene, genotype Nn, whereas all other sires except three were of genotype NN. Large differences between Nn and NN were found in this study: daily gain 24.90 g day(-1) (SE 11.5), feed conversion -0.168 kg kg(-1) (SE 0.031), lean percentage 2.47 (SE 0.37). In the above mentioned comparisons of the lines PIC 416 benefits from half of the Nn-NN difference. This is a relevant comparison in the future scenario where all production sows will be of genotype NN.