The Effects of Floor Temperature, Supplemental Heat and Drying at Birth on Neonatal Swine1

Abstract

The objective was to determine the effects of floor temperature (20 or 30 C), supplemental heat (heat lamp or light bulb) and drying at birth on piglet survival to day 5. Rectal and infrared skin temperatures were taken on 326 piglets for the first 8 hr postpartum. Blood samples were obtained at birth, day 2 and day 5 and analyzed for thyroxine (T4), triiodothyronine (T3) and cortisol by radioimmunoassay. Weight of each pig was recorded at birth and on days 1, 2, and 5. Survival rates were monitored daily. It was postulated that piglets not dried at birth might have increased heat conservation because of vasoconstriction, which may increase the thermostability and survival of the neonate. Supplemental heat was the only treatment that increased rectal temperature after 3 hr postpartum. Skin temperature at 1/2 and 1 hr was increased by drying, and supplemental heat resulted in elevated skin temperatures from 5 to 8 hr postpartum. Plasma cortisol concentrations were elevated at 2 days of age among pigs not given supplemental heat, but no differences were detected at 5 days of age. Plasma T4 concentrations at 5 days of age were lower among male pigs, pigs on the 30 C floor and pigs given supplemental heat. No significant treatment effects were noted in T3 values at day 5. Pig weights and survival rate at 5 days of age were influenced by the interaction of floor temperature and drying pigs at birth. Pigs dried at birth and kept on the 20 C floor were heavier than those on the 30 C floor, whereas those not dried and kept on the 20 C floor weighed less than those on the 30 C floor. The rate of survival was significantly lower among pigs dried at birth and kept on the 20 C floor than among those not dried and on the 30 C floor (80.9 vs 97.2%), while drying had no effect on survival rate among pigs on the 30 C floor (94.5 vs 93.1%).

The Changes in Skin Temperatures of Periparturient Sows

“…In pigs, its changes have been described in detail e.g. in context with changes in the thermal environment (Holub 1958;L:ivicka et al 1960;Lyhs et al 1969;McGinnis et al 1981). Recently introduced measurement of skin temperatures over various parts of body surface by means of thermistor probes provides average temperature values, however, without an accurate distribution pattern and time dynamics of these changes.…”

Effects of Season, Floor Type, Air Temperature and Snout Coolers on Sow and Litter Performance1

“…Litters raised in cooler environments (10 to 20 C) experience higher mortality due to chilling (Taylor et al, 1952;Parker et al, 1980;McGinnis et al, 1981 ;Nienaber et al, 1985). Although piglets are able to increase heat production by increasing their metabolic rate at an air temperature of 20 C, the pig's lack of insulation, sparse pelage and a large surface area-to-body weight ratio handicaps the pig in maintaining homeostasis (Mount, 1968;McGinnis et al, 1981). Therefore, we speculate that increased mortality at 18 C may have been due to chilling of piglets (sow feed intake was normal), but at 30 C increased mortality may have been due to reduced sow feed intake and reduced milk production.…”

In newborn piglets does drying versus no intervention reduce the risk of mortality pre-weaning?

“…From the evidence it is clear that drying piglets can result in lower mortality however, a simpler method may be to place the piglet under a heat lamp (Andersen et al, 2009). Drying piglets with stimulation without combination of other strategies was only assessed in four studies (Christison et al, 1997;McGinnis et al, 1981;Pan, 1995;and Vasdal et al, 2011), of which one study did not record mortality (Pan, 1995), one study showed no effects on mortality and two showed an improvement in mortality where piglets were dried (Christison et al, 1997;and Vasdal et al, 2011). A further two studies included drying as part of an "advanced care" around farrowing which included a number of interventions (Dewey et al, 2008;and White et al, 1996).…”

“…However, maximal care litters did end up heavier at 16 days with no impact on mortality between groups (Dewey et al, 2008). Another study with multiple treatments looked at the impacts of drying piglets with a paper towel, the addition of supplemental heat and two different floor temperatures on growth and thermoregulation (McGinnis et al, 1981). Within this study piglets which were dried had higher rectal temperatures at 1 hour old and higher skin temperatures at 30 minutes and 1 hour of age (McGinnis et al, 1981).…”