The effect of electronic cooling pads and Moringa oleifera supplementation from late gestation to weaning on sow production performance under heat stress conditions.

Abstract

Lactating sows and their litters are particularly vulnerable to heat stress (HS). Heat stress decreases sow fertility, feed intake, milk production, and litter growth. Approaches are needed to mitigate the negative effects of HS on animal welfare and oxidative damage to tissues. The objective of this study was to measure the efficacy of conductive heat removal using electronic cooling pads (ECP) and feeding Moringa oleifera (4% of the diet, M), a feedstuff high in antioxidants, to sows from late gestation to weaning on their welfare and production performance. A study was conducted using a 2 × 2 factorial design of treatments, with mixed parity Yorkshire x Landrace sows (n=48). The sows were exposed to moderate heat stress conditions from gestation d110 to d21 of lactation. To achieve moderate heat stress, farrowing room temperature was increased incrementally daily from 25 º C to 32º C between 0800-1100 and decreased from 32º C to 26 ºC between 1700-2000. Sows were limit fed during gestation (1.36 kg 2X/d) and fed ad libitum post farrowing. Treatments included HS+control corn-soybean meal based diet (HS+CS), HS+M, ECP+CS, ECP+M (n=12/treatment). Sow respiration rate (RR) and rectal temperature (RT) were measured 4-times daily (0600, 1300, 1600, 1900). The use of ECP decreased lactating sow RR (HS = 66.6 bpm, ECP = 28.3 bpm, P < 0.0001), RT (HS = 39.2 ºC, ECP =38.8 ºC, P = 0.003), and lactation BW loss (HS= -21.67 kg, ECP = -5.1 kg P = 0.002). ECP by time-of-day interactions (P < 0.01) existed for RR and RT, with ECP having a greater impact from 1300 to 1900, than at 0600. ECP increased lactation feed intake (P = 0.02). An ECP by diet interaction (P= 0.0004) indicated ECP increased lactation feed intake for the sows fed the CS diet (6.48 kg/d vs 4.42 kg/d, P = 0.0004), but did not affect feed intake of sows fed the M diet. Treatment did not affect litter weaning weight (P = 0.14). Moringa increased percent fat in milk (M=12.28%, CS =11.06%, P = 0.05). The reduction in sow RR, RT, and increased feed intake with lower loss of BW, indicate that ECP improved sow wellbeing in the HS environment. Neither ECP or M affected litter growth, despite M increasing fat content of milk and ECP-CS increasing feed intake.