229 Effects of sire line on survivability traits of commercial pigs sired by PIC 800 or a North American competitor Duroc Line from birth to market

Abstract

Abstract This study aimed to evaluate differences in survivability traits on pigs originating from two sire lines from birth to market. A total of 28,426 commercial pigs sired by either PIC 800 boars (n = 13,960 pigs) or a North American competitor Duroc line (Sire A; n = 14,466 pigs) were used in this study. PIC Camborough sows from 2 sister-sow farms were bred using semen from both genetic lines was mated equally and randomly across sows to ensure sire lines and parity of dams were balanced across farms. Pigs were individually identified at birth by genetic line and cross-fostering was done following standard farm practices. At weaning (average wean age 22 d of age, average body weight 6.8kg), pigs from both lines were sent to nurseries or Wean-to-finish sites (n = 11,541 PIC 800 and n = 11,922 Sire A), comingling in the same barns and pens. Starting inventories for each genetic line were recorded at weaning for all sites, end of nursery (4 wk post weaning), and 1 to 2 wk before start of marketing (target market weight 127kg at 160 d of age). For each production period, information on mortality and morbidity traits (n = 10,600 PIC 800 and n = 10,974 Sire A) was collected. Data were analyzed using R separately for each production period (i.e., Pre-weaning, Grow-to-finish, and Wean-to-finish) and not pooled from birth to market due to some groups not being kept intact. Morbidity and mortality data were analyzed using binomial models with a fixed effect of sire line and a random effect of sow farm or nursery/wean-to-finish site for pre-wean traits or post-weaning traits, respectively. Pigs from farms without removal reason record were excluded from analysis of removal reasons (Table 1). Overall pre-wean mortality was less (P ≤ 0.05) for PIC 800 pigs than Sire A pigs (8.5 vs. 9.6%, for PIC 800 and Sire A, respectively), mostly due to having fewer (P ≤ 0.05) pigs laid-on (4.8 vs 5.9%, respectively). At 4 wk post weaning, PIC 800 pigs had less (P ≤ 0.05) fallout rate than Sire A pigs (2.5 vs 3.5%, for PIC 800 and Sire A, respectively), with no differences (P > 0.05) in mortality rate (1.2 vs 1.3%, respectively). Grow-to-finish morbidity and mortality rates were less (P ≤ 0.05) for PIC 800 (2.1 and 1.3%, for morbidity and mortality rates, respectively) compared with Sire A (2.5 and 1.8%, respectively). Likewise, wean-to-finish morbidity and mortality rates were less (P ≤ 0.05) for PIC 800 (2.5 and 3.7%, for morbidity and mortality rates, respectively) compared with Sire A (3.0 and 4.7%, respectively). Results suggest PIC 800 sired pigs consistently had lower incidence of morbidity and mortality than Sire A pigs across all stages of production included in this study.