Preference among cooling systems by gilts under heat stress.

Abstract

A preference experiment was conducted to compare and evaluate the use of three cooling systems by mature gilts. Systems evaluated were snout coolers (S), drip coolers (D), and conductive cool pads (P). Preference for cooling system and pen position were continuously monitored and evaluated during daily heat stress conditions (34.2 +/- 2.8 degrees C), nightly warm conditions (26.6 +/- 2.3 degrees C), and for total time. The physiological variables of respiration rate (RR) and rectal temperature (Tr) were measured at three separate times daily. Gilts naive to the cooling systems were individually housed in pens with three free stalls, each stall containing a different cooling system. After 1 d of warm temperature (27.6 +/- 2.5 degrees C) acclimation, gilts were exposed to 10 h of the heat stress conditions and 14 h of the warm night conditions each day for six consecutive days. Cooling system use was higher during the hot period (80.2%) than during the warm period (66.2%). The conductive cool pad was preferred over the drip cooler (P < .02) and the snout cooler (P < .0002). The preference for the conductive cool pad persisted in the warm period. Cooling system use had a significant effect on Tr and RR (P < .001). The Tr (P < .005) and RR were lower (P < .005) with the use of the conductive cool pad, whereas the drip cooler and snout cooler showed no effect on these variables.

Evaluating equations estimating change in swine feed intake during heat and cold stress1

“…Heat abatement, ADG, days of exposure, housing density parameters, housingtype parameters, photoperiod, study location, experimental protocol, and BW also had direct effects on feed intake. This result is in agreement with previous studies that suggest that housing system (Morrison et al, 2007), stocking density (Jensen et al, 2012;Hemsworth et al, 2013), diet (Wolp et al, 2012), heat abatement strategy (Bull et al, 1997), and duration of exposure to heat stress (Pearce et al, 2013) affect physiological and behavioral responses to heat stress.…”

Avaliação de tipos de ventilação em maternidade de suínos

“…Os resultados aqui obtidos podem ser comparados com os obtidos por BULL et al (1997), que analisaram o desempenho de marrãs em sistemas de resfriamento (resfriamento adiabático, gotejamento e resfriamento no focinho) e mediram a temperatura retal e a taxa de respiração, concluindo que os animais preferem o resfriamento adiabático, ou seja, as trocas de calor por condução, apresentando menor taxa de respiração e menor temperatura retal. Os resultados dos valores das médias obtidos são apresentados na Tabela 4.…”

Effects of shaded versus unshaded wallows on behavior, performance, and physiology of the outdoor lactating sow1,2

“…Some of these include misters, sprinklers, snout or evaporative coolers, and ventilation fans (Bull et al, 1997). For sows housed in an outdoor system at any stage of production, heat-stress amelioration solutions can be less straightforward, but providing shade is one possibility.…”

“…Furthermore, under natural conditions, feral sows have been observed to alter their behavioral pattern by seeking shelter during the daytime hours and then becoming increasingly active during the cooler night hours (Ingram, 1976). Both indoor-and outdoor-housed lactating sows show adverse effects to prolonged periods of heat stress in terms of performance and behavior (Edwards et al, 1968;McGlone et al, 1988), physiology (Bull et al, 1997), and immune function (MorrowTesch et al, 1994). These behavioral, physiological, and performance alterations may adversely affect the welEffects of shaded versus unshaded wallows on behavior, performance, and physiology of the outdoor lactating sow fare of the piglets and the overall profitability for the producer.…”