Genetic and environmental factors that affect production traits of young breeding swine

Abstract

Age (E90) and backfat thickness (GD) were evaluated at 90 kg live weight, in 1614 young breeders from farms A (A) and 1709 from farm B (B), of Large White (LW), Duroc (D), Hampshire (H), Landrace (L), and IP60, breeds. ANOVA was applied by least squares, including in the model: month of birth (M: 4-91 to 1-92 in A; 1-91 to 12-91 in B); sex (S: M, H); race (R: five o'clock in A; LW and LR in B); parent within the breed (P/R). The significant effects were: for E90, in A: M, S, R and P/LW (P<.01) and P/D and P/LR (P<.05); in B: all effects (P<.01); for GD, in A: M, S, R, P/D and P/H (P<.01); in B: M, S, R and P/LR (P<.01) and P/LW (P<.05). The means for E90, in A, 157.6 ± 0.6; in B, 151.5±0.55days; for GD, in A, 14.16±0.12; in B, 14.47±0.11mm. Males outperformed females in E90 by -8.3 days (5.13% advantage) in A and by -9.6 days (6.12%) in B. The monthly mean decreased from 168.9 in 4-91 to 154.0 days in 1-92 in A and fluctuated between 156.6 and 144.5 days in B. The advantage of males in GD was -0.98mm (6.69%) in A and -2.02mm (13.05%) in B. The monthly mean decreased from 15.03 in 4-91 at 14.29mm in 1-92 in A and fluctuated between 16.98 and 13.49mm in B. In both farms the lower E90 and GD correspond to LW (149.3 and 13.28 in A; 148.4 and 13.79 in B). The inheritance indices in A and B were: for E90, 0.13 and 0.20; for GD, 0.17 and 0.15; the E90-GD genetic correlation was 0.05 and 0.14; the phenotypic, 0.47 and 0.32; and the environmental one, 054 and 0.36 respectively.