Effect of high temperature and feeding level on energy utilization in piglets.

Abstract

The effect of temperature (23 or 33 degrees C) and feeding level on components of energy balance was studied in seven groups of individually reared Piétrain x (Landrace x Large White) littermate piglets. Within each litter, one pig was reared at 23 degrees C and given a predefined feeding level close to ad libitum (23AL pigs), one was reared at 33 degrees C and also fed close to ad libitum (33AL), and one was reared at 23 degrees C and pair-fed to the 33AL pig (23PF). Piglets of one litter were acclimated during 2 to 4 wk to their experimental temperature in temperature-controlled rooms before being transferred (one per week) to a respiration chamber for measurement of nitrogen and energy balances. The average initial BW was 22.4 kg. The data on O2 consumption, CO2 production, and physical activity were collected over seven consecutive days and used to calculate total heat production (HPtot) and its components: fasting heat production (FHP), heat production due to physical activity (HPact), and thermic effect of feed (TEF). A preliminary trial was conducted in which heat production was measured in three piglets according to a Latin square design at 23, 25, and 27 degrees C. Total heat production was, but activity-free heat production was not, affected by temperature, and no firm conclusions could be drawn as to whether 23 degrees C was within the thermoneutral zone of fed piglets. In Trial 2, the combination of increased temperature and reduced feed intake resulted in a 20% lesser heat production in 33AL than in 23AL pigs. This was due to a reduction in both TEF (-39%) and FHP (0.642 vs 0.808 MJ x d(-1) x kg BW-0.60). Despite the shorter duration of standing activity, HPact was slightly higher at 33 degrees C, probably due to hyperventilation at this temperature. With similar feeding levels (23PF vs 33AL), HPtot and activity-free heat production were less at 33 degrees C and energy retention as protein (+6%) and fat (+31%) was increased. Because HPact was similar for both treatments, the greater energy retention for 33AL seemed to be due to a greater utilization of feed energy or to a reduced maintenance requirement (i.e., reduced FHP). However, the type of stress imposed on 23PF and 33AL pigs was different and may have affected energy metabolism. The results suggest that the reduction in heat production of piglets at high ambient temperatures is caused by a reduction in voluntary feed intake and differences in energetic efficiency. The mechanisms for the lesser efficiency at 23 degrees C compared to 33 degrees C (at the same level of feed intake) remain unclear.

Effect of temperature level on thermal acclimation in Large White growing pigs

“…These results suggest that the apparent efficiency of food utilization for growth would increase with time when temperature was above 288C. Brown-Brandl et al (2000) and Collin et al (2001a) showed a reduction of fasting heat production (FHP) under hot conditions in temperature-acclimated pigs. According to Koong et al (1982) and van Milgen et al (1998), this reduced FHP is generally explained by an indirect effect of reduced feed intake on viscera mass.…”

“…According to these authors, this large variability can be explained by many factors including breed, BW, degree of fatness, diet composition and temperature range. The reduced ADFI under hot conditions in pigs leads to reduced thermogenesis and heat stress (Collin et al, 2001a). Most of the published results on the effect of elevated temperature on pigs performance were obtained in pigs previously acclimated to the experimental temperature for 3 to 10 days with a relative humidity ranging between 40% and 60%.…”

Lisina digestível para suínos machos castrados de alta deposição de carne submetidos a estresse por calor dos 30 aos 60 kg

“…Esta hipótese está coerente com o relato de Santomá & Pontes (2004) de que o padrão de redução do consumo de ração aumenta de forma direta com a intensidade do estresse por calor, embora em uma relação não-linear. No entanto, de acordo com Collin et al (2001b), isoladamente, a redução do consumo diário de ração ocasionada pela alta temperatura não explicaria o menor ganho de peso pelos animais.…”

“…Neste trabalho, a deposição de gordura dos animais mantidos a 34ºC foi, em média, 25,6% menor (P<0,01) que a daqueles mantidos a 30ºC. Esses resultados corroboram os obtidos por Collin et al (2001b), que atribuíram a menor retenção de energia na forma de proteína e gordura nos animais, ao menor consumo de ração.…”

Achilles heel of a powerful invader: restrictions on distribution and disappearance of feral pigs from a protected area in Northern Pantanal, Western Brazil

“…Furthermore, the SDM approach showed that habitats with greater suitability for feral pigs are those predominantly herbaceous (around 80% coverage), interspersed with patches of seasonally dry forest (optimum between 35 and 40% coverage) and not too far from water bodies (around one kilometer). S. scrofa has a low tolerance to high temperature in nature due to the lack of sweat glands or other efficient physiological cooling mechanisms (Baber & Coblentz 1986;Choquenot & Ruscoe 2003;Collin et al 2001;Huynh et al 2005b), and low ability to concentrate urine (Gabor et al 1997;Zervanos and Naveh 1988), being dependent on shaded habitats and reservoirs of water to avoid dehydration and promote thermoregulation (Baber & Coblentz 1986;Cuevas et al 2013b;Dexter 1998;Ilse & Hellgren 1995). Data available for southern Pantanal shows that the species has a high fidelity, returning to resting sites where they stay during the hottest hours of the day (OliveiraSantos 2013).…”