Heidi Mai-Lis Andersen

Growing pigs’ drinking behaviour: number of visits, duration, water intake and diurnal variation

Individual drinking patterns are a potential tool for disease monitoring in pigs. However, to date, individual pig drinking behaviour has not been described, and effects of external factors have not been examined. The aim of this study was to perform detailed quantification of drinking behaviour of growing pigs and to examine effects of period of day and effects of competition for access to the drinking nipple on the drinking behaviour, amount of water used and water wastage. In all, 52 cross-bred castrated male pigs (live weight 20.5±1.7 kg; mean±s.d.) maintained as either 3 (N3) or 10 (N10) pigs per pen and water nipple (four groups/treatment) were used. All pigs were fitted with a transponder ear tag. A radio frequency identification reader recorded and time stamped visits at the nipple. In each pen, water flow was logged every second. The drinking behaviour was recorded for 4 consecutive days and analysed using a linear mixed model. Overall, the pigs spent 594 s at the nipple during 24 h distributed among 44 visits. During this period, 5 l of water were used, of which >30% was wasted. Social competition did not affect the drinking behaviour over 24 h, except for the proportion of interrupted visits where pigs, kept with recommended nipple availability (N10), showed an increased proportion of interrupted drinking bouts compared with pigs kept at very low level of competition (N3) (0.18±0.01 v. 0.11±0.01; P<0.01). However, splitting data into 8-h periods (P1, P2, P3) starting from 0600 h revealed differences between treatments, showing that in N3, water use per visit was lower in P1 than P2 and P3 (110±10 v. 126±7 and 132±7 ml; P<0.05), whereas in N10, the water used per visit was higher during P3 than during the other periods (P1: 107±14 ml, P2: 112±10 ml v. P3: 151±10 ml; P<0.001). A similar pattern was found for visit duration. In N3, fewer nipple visits were observed in P2 than P1 (15.6±1.2 v. 22.0±1.2; P<0.001), whereas no difference was found between P1 and P2 in N10. The results demonstrate that growing pigs at the two levels of competition maintained a comparable level of 24 h water intake by changing behavioural variables involved in drinking. This dynamic characteristic of drinking behaviour means that if individual drinking patterns are to be used as disease monitoring tools, it is important to consider effects of external factors and include data on period level to allow rapid detection of behavioural changes.

Effect of radiant heat at the birth site in farrowing crates on hypothermia and behaviour in neonatal piglets

It has been documented that floor heating of the farrowing area in loose housed sows improves survival of piglets significantly. However, today, the majority of farrowing pens are designed with crating of sows and slatted floor at the birth site. The aim of this study was to investigate whether providing radiant heat at the birth site to new-born piglets in pens with crated sows reduced hypothermia, time to first milk intake and growth of the piglets during the 1(st) week. Second parity Danish Landrace×Yorkshire sows (n=36) were randomly divided into two groups: Control (CG) and heat (HG). In the area behind the sow (zone 1), two radiant heat panels were mounted above the slatted floor in the HG. The farrowings were attended, and the heaters were turned on at birth of first piglet and turned off 12 h after. Birth time, time to leave zone 1, time to first contact with udder and time to first suckling were registered by direct observation. The piglets rectal temperature (RT) was measured 15, 30, 60, 120, 180, 240 min after birth and 12, 14 and 24 h after birth of first piglet. Piglets were weighed at birth, 24 and 48 h and 7 days after birth. Data were analysed in a mixed model in SAS. The drop in RT was lower in HG compared with CG (P=0.002), and the RT in HG remained higher than in CG from 30 to 240 min after birth (P<0.05), whereas no difference was found at 12 h after birth of first piglet (P=0.92). Piglets in HG stayed longer in zone 1 than those in CG (P=0.01), whereas time to reach udder (P=0.35) and to first suckling (P=0.56) did not differ. No difference in weight gain was found between piglets in HG and CG at 24 h (P=0.23), 48 h (P=0.28) and 7 days after birth (P=0.44). Birth weight had a positive effect on RT (P<0.001) and reduced time to leave zone 1 (P<0.01), reach udder (P<0.001) and time to first suckling (P<0.001). The results showed that radiant heating behind the sows reduced hypothermia in new-born piglets and indicate that providing heat during the first half hour after birth is important.

The effect of varying duration of water restriction on drinking behaviour, welfare and production of lactating sows

Access to drinking water is essential for animal welfare, but it is unclear if temporary water restriction during the night represents a welfare problem. The aim of the present study was to investigate the effect of various durations of nightly restriction of water on thirst in loose housed lactating sows from day 10 to 28 of lactation. A total of 48 sows were deprived of water for either 0 h (n=12; control), 3 h (n=12; 0500 to 0800 h), 6 h (n=12; 0200 to 0800 h) or 12 h (n=12; 2000 to 0800 h). Control sows consumed 22% of their water intake during the night (2000 to 0800 h), whereas water consumption during this time was reduced to 13%, 7% and 0% in sows restricted for 3, 6 and 12 h. With increased duration of nightly water restriction a reduced latency to drink (26.8, 18.0, 5.3 and 6.7 min for 0, 3, 6 and 12 h sows; P<0.001) and an increased water intake during the 1st hour after water became accessible (2.1, 3.4, 4.7 and 5.6 l for 0, 3, 6 and 12 h sows; P<0.001) was seen. During the last 30 min before water became accessible more sows deprived of water investigated (0%, 50%, 75%,and 50% of 0, 3, 6 and 12 h sows; P<0.01) or forcefully manipulated (0%, 17%, 50% and 33% of 0, 3, 6 and 12 h sows; P<0.05) the water trough, suggesting frustration and a negative experience of thirst. When all signs of imminent water access were provided, but access was delayed by 25 min, a tendency for more of the sows deprived of water for 6 and 12 h to interact forcefully with the water trough was seen (22%, 18%, 42% and 67% of 0, 3, 6 and 12 h sows; P=0.09). Duration of water restriction did not affect water consumption on a 24-h basis, nursing behaviour or performance. In conclusion, behavioural indicators of thirst increased with increasing duration of nightly water restriction in lactating sows.