Behaviour and performance of lactating sows housed in different types of farrowing rooms during summer

Abstract

AbstractThirty mixed-parity Landrace×Large White sows were used to evaluate the effects of the type of farrowing room on 28-day lactation behaviour under tropical conditions during summer. The sows were allocated in a completely randomised design with three treatments with 10 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of a conventional farrowing room (T1); a conventional farrowing room with floor cooling under the sow (T2); and a semi-outdoor farrowing room without a cage and with access to a fenced field (T3). The sows from T1 and T2 groups were exposed to mean maximum and minimum environmental temperatures of 25.7 and 21.0°C, respectively, and the sows from the T3 group to average maximum and minimum environmental temperatures of 26.5 and 20.7°C, respectively. The feed consumption of T3 sows was numerically higher than the T1 and T2 sows (+9.5% on average). The body-weight loss was influenced at 28days (P<0.10) by treatment, being that the T3 sows gained weight (+4.7kg) while the T1 and T2 sows lost weight (−11.9 and −3.7kg, respectively for T1 and T2). The T3 sows showed a higher percentual litter mortality than the T1 and T2 sows (3.2% vs. 0% vs. 7.8%, respectively for T1, T2 and T3 sows). From farrowing until day 28 of lactation, the T2 and T3 sows showed higher lactation efficiency when compared with the T1 sows (72% vs. 87% vs. 88%, respectively for T1, T2 and T3 sows). The T1 sows showed higher (P<0.01) frequencies of visits to the feeder and drinker (+38% on average). The T3 sows spent more time (P<0.01) at the drinker than T1 and T2 sows (23 vs. 23 vs. 32min, respectively for T1, T2 and T3 sows). The T3 sows showed a higher (P<0.10) frequency of nursing than the other treatments (+15% on average). T1 and T2 sows were found to spend more time (P<0.01) performing other postures during 24h than sows maintained in T3 (50 vs. 51 vs. 22min/d, respectively for T1, T2 and T3). It is concluded that cooling of the floor under the sow in the conventional farrowing room or the use of semi-outdoor farrowing rooms improves the thermal environment and the lactation efficiency of the sows housed in hot ambient temperatures at 28-day lactation in the summer period, indicating an improved welfare