Effect of dietary arginine supplementation and environmental temperature on sow lactation performance

Abstract

The objective of this study was to investigate whether supplemental dietary arginine increases lactation performance in sows subjected to a hot environment. A total of 66 multiparous sows were allotted in a 2×3 factorial arrangement, consisting of two environments and three dietary treatments. Sows were maintained in a thermoneutral environment of 20°C (TN) or heat-stressed in a hot environment of 29.4°C (HS), starting on day 95 of gestation. From day 110 of gestation to weaning, sows were provided one of three corn–soybean meal based dietary treatments formulated to contain 0.96% arginine (1:1 arginine:lysine), 1.34% arginine (1.4:1 arginine:lysine), and 1.73% arginine (1.8:1 arginine:lysine), for control (C), medium (ME), and high (HI) dietary treatments, respectively. Respiration rate and rectal temperature increased in HS sows compared to TN sows ( P<0.01) and heart rate decreased in HS sows ( P<0.05) compared to TN sows. Arginine supplementation did not affect heart rate and respiration rate; however, it tended to decrease rectal temperature ( P<0.10) in sows fed the ME diet in the thermoneutral environment. Litter weight gain ( P<0.05) and voluntary sow feed intake ( P<0.01) decreased and sow weight loss increased ( P<0.01) in the hot environment. Dietary arginine supplementation did not improve litter weight gain ( P>0.10) for either HS or TN sows. Arginine supplementation reduced feed intake ( P<0.05) and tended to reduce body weight loss (P0.06) during lactation. In conclusion, supplemental arginine in lactating sow diets in a hot environment did not improve litter performance but reduced sow weight loss and increased sow feed efficiency.