Impacts of shade on physiological and behavioural pattern of Dehong buffalo calves under high temperature

Abstract

Shade shelter is widely used to reduce heat load for farm animals, but little research focus on the cooling effects for Dehong buffalo calves. The aim of this experiment was to evaluate the impacts of shade cooling on the physiological and behavioural parameters for Dehong buffalo calves. Shade with 99% blockage of solar radiation was covered on steel frame with a 2.5 m height above the loafing area floor (Shaded). The loafing area of the control group was the same as the shaded group, © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ apart from no shade shelter above the loafing area (non-shaded). Twenty-four Dehong buffalo calves were randomly and averagely allocated to the non-shaded and shaded groups. Six Dehong buffalo calves were loose housed in a barn, and they had access to loafing area. The results showed that the average daily air temperature of the loafing area under shade was lower 1.5 than that of the non-shaded loafing area. No difference in rectal temperature was found between the non-shaded and shaded calves (P > 0.05), but respiration rate of the non-shaded group in noon (12:00h, 31.6 breaths) and evening (18:00h, 28.5 breaths) was greater than for calves in shaded group (26.1 and 25.3 breaths, respectively) (P < 0.05). When ambient temperature exceeded 30 , shaded calves spent much of their time (21.7%) lying in the loafing area, and no calf in non-shaded group preferred to lie in the loafing area with strong solar radiation (P < 0.05). The use of shade for calves was affected by thermal environment, and the use of shade was greater (41.4%) in hot weather (above 30 ) than that of the warm weather (22-29 ) (P < 0.05). In conclusion, the provision of shade above the loafing area is conducive to improving thermal environment for Dehong buffalo calves in subtropical area characterized with high ambient temperature coupled with high humidity in summer.

Effect of Silvopastoral Systems in the Thermoregulatory and Feeding Behaviors of Water Buffaloes Under Different Conditions of Heat Stress

“…It is possible that under situations of intense heat stress in silvopastoral conditions, the sensation of heat stress is not being perceived by the buffaloes, due to the contribution of trees in providing shade and improving active feeding behavior ( 50 , 51 ). In the same way, shade in the silvopastoral system improved pasture quality and quantity in several studies ( 5 , 10 , 52 ).…”

Heat stress in dairy calves from birth to weaning

“…Shading reduces the temperature both inside and outside the hutch (Coleman et al ., 1996; Spain and Spiers, 1996; Gu et al ., 2016; Kovács et al ., 2019). Respiratory rate of calves is usually lower under shade (Spain and Spiers, 1996; Gu et al ., 2016) and calves spend more time lying in shaded areas (Gu et al ., 2016). Shading also provides more comfortable conditions for caretakers in all seasons (Coleman et al ., 1996).…”

Thermoregulatory and Feeding Behavior under Different Management and Heat Stress Conditions in Heifer Water Buffalo (Bubalus bubalis) in the Tropics

“…While wallowing allows for cooling with water or mud, this cannot be considered as enough for animal welfare, because radiation in the head and spine is not avoided [ 11 , 20 ]. It would be interesting to have data on how radiation influences the temperature in different areas of the body, as was done under infrared thermography, through which microvascular changes in the head were previously studied, particularly in the area of the eye orbits and in the muscles of the spine, scrotum, or mammary gland [ 24 , 25 ], both while in and out the water, and with or without tree shade [ 26 ].…”

“…The differences in sheltering behavior during the intense heat stress season are probably influenced by the low nutritional values of the pastures in the CVS [ 26 , 30 ], which forces the animals to return earlier to the grazing paddock in order to satisfy their nutritional requirements.…”