Effects of grouping unfamiliar cohorts, high ambient temperature and stocking density on live performance of growing pigs

摘要: Ninety-six crossbred intact male pigs (34.5 ± 3.5 kg BW) were allocated by weight and vocalization score to a 2 × dynamic experimental design including two stocking densities (1 or m /pig), temperatures (22°C 30°C), short groupings of unfamiliar cohorts (six as one pig per group, six group). The study was conducted over 8 wk, live gain (WTG) feed intake (FI; as-fed basis) measured weekly. During the first week, housed in individual pens from four independent rooms. To group pigs, pen partitions removed. Pigs grouped Rooms 3 wk 4, 1 4 during 7. Temperature increased 22°C 30°C Pen replaced at end 7 return their pens. Grouping decreased FI (15.08 0.43 vs. 14.03 0.41 P < 0.10), (17.42 0.46 14.24 kg; 0.01). In addition, grouping had negative effect (P 0.001) on WTG (7.38 0.28 5.71 kg) (6.70 0.26 2.99 kg). For raising temperature 0.01) (7.49 0.29 6.41 3.37 0.38 2.62 7). Mean with treatment only (15.49 0.33 20°C compared 12.99 30°C). Compensatory evident after treatments ceased 6, whereby previously heat-treated higher (17.97 0.45 than animals individually (12.99 Stocking density effects noted high ceased. instance, 5, low-density-housed grew faster high-density counterparts (9.04 7.49 conclusion, under conditions this study, ambient detrimental performance, these reversible.