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

Abstract

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 piglet's 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.

Effect of method of drying piglets at birth on rectal temperature over the first 24 h after birth1

“… Caldara et al (2014) found that the minimum body surface temperature was reached at 15 min after birth. However, similar to the current experiment, a number of studies have found that the minimum temperature occurred at 30 min after birth ( Pattison et al, 1990 ; Andersen and Pedersen, 2015 ; Xiong et al, 2018 ; Cooper et al, 2019 ). There was considerable variation in the estimates of minimum temperatures between these studies, ranging from 33.6 °C ( Xiong et al, 2018 ) to 36.6 °C ( Pattison et al, 1990 ).…”

“…For example, measuring body surface temperature using thermal imaging ( Caldara et al, 2014 ) compared with measurement of rectal temperature (e.g., Cooper et al, 2019 ). In addition, other parameters varied between studies, such as piglet birth weight (e.g., 1.2 kg, Andersen and Pedersen, 2015 compared with 1.5 kg, Cooper et al, 2019 ) and room temperature (e.g., 18 to 20 °C, Kammersgaard et al, 2011 compared with 23 °C, Xiong et al, 2018 ). Despite these differences, the overall conclusion from this and previous research is that all piglets experience a large temperature decline in the early postnatal period.…”

“…A number of studies estimated the linear regression relationship between piglet body temperature and birth weight at various times after birth, and all showed positive relationships ( Pattison et al, 1990 ; Caldara et al, 2014 ; Andersen and Pedersen, 2015 ). However, these studies only evaluated undried piglets, and, therefore, these results can only be compared with the Control treatment of the current study.…”

Effect of drying and/or warming piglets at birth on rectal temperature over the first 24 h after birth

“…However, the warming treatment in that study started at 15 min after birth, by which time piglet temperatures would have decreased considerably. A number of studies added localized heat sources to the farrowing pen without confining piglets to the heated areas (e.g., McGinnis et al, 1981 ; Andersen and Pedersen, 2015 ) and found a smaller effect on rectal temperatures than the current study, suggesting that confining piglets to a heated area was a more effective approach. Instead of providing a localized heat source for warming piglets, some studies have evaluated the impact of increasing the temperature of either the farrowing pen or the entire room.…”

Radiant heat increases piglets’ use of the heated creep area on the critical days after birth

“…According to the results obtained in the present study, radiant heat ensured a higher use of the creep area these critical days and might, therefore, decrease piglet mortality due to crushing and hypothermia. Further, radiant heat has in previous studies been proved effective in reducing hypothermia in new-born piglets (Andersen and Pedersen, 2015;Pedersen et al, 2016).…”