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

Lactating sows and their litters are particularly vulnerable to heat stress (HS). HS decreases fertility, feed intake, milk production, and litter growth of sows. 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 × Landrace sows (n = 48). The sows were exposed to moderate HS conditions from gestation day 110 to day 21 of lactation. To achieve moderate HS, the farrowing room temperature was increased incrementally daily from 25 °C to 32 °C between 0800 and 1100 hours and decreased from 32 °C to 26 °C between 1700 and 2000 hours. Sows were limit fed during gestation (1.36 kg 2X/d) and fed ad libitum post farrowing. Treatments included HS + control corn-soybean meal (CS)-based diet (HS + CS), HS + M, ECP + CS, ECP + M (n = 12/treatment). Sow respiration rate (RR) and rectal temperature (RT) were measured four times daily (0600, 1300, 1600, and 1900 hours). The use of ECP decreased lactating sow RR (HS = 66.6 bpm, ECP = 28.3 bpm, P < 0.0001), RT (HS = 39.2 °C, ECP = 38.8 °C, P = 0.003), and lactation body weight (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 hours, than at 0600 hours. ECP increased the intake of lactation feed (P = 0.02). An ECP by diet interaction (P = 0.0004) indicated that ECP increased the intake of lactation feed for the sows fed the CS diet (6.48 vs. 4.42 kg/d, P = 0.0004), but did not affect the feed intake of sows fed the M diet. The 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 and RT, and increase in feed intake with lower loss of BW indicate that ECP improved sow well-being in the HS environment. Neither ECP nor M affected litter growth, despite M increasing fat content of milk and ECP-CS increasing feed intake.