Effect of familiarity with the environment on the behaviour and performance response of sows and piglets to grouping during lactation

Abstract

To determine whether the disruption in suckling patterns and cross-suckling which are observed in multisuckling systems could be reduced by modifying pen design to permit prior familiarity of animals with the environment, 32 Large White×Landrace sows and litters were allocated between two treatments, each with four replicate groups of four sows and litters. On Day 7 after farrowing, T1 sows and litters were moved from individual farrowing crates to a modified multisuckling pen, where each sow and her piglets were enclosed in an individual pen, whilst T2 sows and litters remained in the farrowing house. Grouping occurred on Day 14; in T1 the gate behind each individual pen was opened to allow the animals voluntary access to a communal area. T2 animals were moved directly from the farrowing house and grouped in an unfamiliar multisuckling pen of the same size with conventional open layout and a single large creep area for the piglets. Overall mortality rate in the two systems was not significantly different, but more piglets tended to be crushed in each treatment in the week following first transfer to the experimental pens ( P<0.10). Frequency of suckling attempts (1.47 vs. 0.95 per hour, S.E.D. 0.05, P<0.01) and proportion of suckling attempts which resulted in milk letdown (0.60 vs. 0.40, S.E.D. 0.07, P=0.06) were lower for T2 than T1 on the day of grouping. The proportion of piglets cross-suckling per litter after grouping was greater in T2 (0.58 vs. 0.22, S.E.D. 3.14, P<0.01). Piglets in T1 spent a greater proportion of time close to their own mother (e.g. 0.45 vs. 0.12, S.E.D. 0.082, P<0.05 on Day 14). Piglet growth rate was significantly reduced in T1 between Day 7 and 14 (211 vs. 260 g/day, S.E.D. 15.3, P<0.01) but only slightly better than T2 after grouping (221 vs. 213 g/day, S.E.D. 7.2, for Days 14–28). After weaning, performance did not differ significantly between piglets from the two systems. Familiarity with the new environment before grouping, and/or greater structural complexity within the pen, therefore reduced the disruption in suckling behaviour after grouping and reduced the incidence of cross-suckling, but did not yield performance benefits.