Evaporative cooling system for gestating and lactating sows: a systematic review

Abstract

Climatic characteristics of the production sites of pigs influence the yield of the system, with breeding sows being a category extremely sensitive to high temperatures, especially when their upper critical temperature is reached. This review evaluated the effects of the evaporative cooling system on environmental, physiological and performance parameters in breeding sows. By means of this review, a bibliographic search was performed using the following keywords: sow; swine; gilt and pig combined individually with the expression ‘evaporative cooling’. A total of 11 papers met the prerequisites determined to compose the systematic review and the studies involved gestating and lactating sows maintained in environments that presented ambient temperatures between 21.5 and 34.8 °C and relative humidity between 32.2 and 84.2%. The evaporative cooling system was used in order to cool the macro or micro environment. It can be concluded that the use of evaporative cooling system promotes increase in feed intake per lactating sow, decrease in weight loss in lactation, increase of weight of piglets at weaning, temperature reduction of the barns and decrease of the respiratory rate of the sows. For gestating sows, no changes in reproductive performance were reported.

Effects of various cooling methods and drinking water temperatures on reproductive performance and behavior in heat stressed sows

“…A report by Ribeiro et al [7] says that temperature above the thermal comfort zone negatively affects feed intake and milk production in lactating sows and the weaning weight in piglets. The improved thermal condition of sows in our study explains the reason for an increase in piglet weight at weaning under AC, CP, and LWT treatment because HS must be sufficiently reduced in sows to reach a unique potential for minimizing weight loss and improving milk production during lactation [25,26]. We agree that AC, CP, and LWT systems helped to alleviate HS in lactating sows.…”

“…Food consumption by lactating sows has always been a challenge during HS, presumably to alleviate the metabolic heat produced during digestion [22,23,24], which clarifies the reason for lower feed consumption in sows during HS and an increase in feed intake at a favorable thermal zone. HS can also alter milk yield by compromising dietary nutrients in the mammary gland through peripheral vasodilation [23,25]. A report by Ribeiro et al [7] says that temperature above the thermal comfort zone negatively affects feed intake and milk production in lactating sows and the weaning weight in piglets.…”