Heat stress mitigation: conductive cooling and Moringa oleifera reduce oxidative damage in sow milk lipids

Heat stress (HS) induces oxidative stress, which damages lipids. Sow milk contains complex lipids, including long-chain polyunsaturated fatty acids (PUFA), which are particularly vulnerable to oxidative damage. This study analyzed the effects of electronic cooling pads (ECP) and dietary supplementation from late gestation to weaning with the antioxidant-rich feedstuff, Moringa oleifera, on the milk lipidome of sows. A 2 × 2 factorial study was conducted with mixed-parity Yorkshire × Landrace sows (n = 48). All sows were fed a basal corn-soybean (CS) meal control diet, but half of the sows (n = 24) were fed the basal diet supplemented with 4% ground Moringa oleifera leaf powder. Dietary treatments began on gestation day 100. Heat stress exposure for all sows began on gestation day 110, with one half of the farrowing crates fitted with ECP. The combination of the two diets and two environmental treatments resulted in four treatment groups: HS fed CS basal diet (HS+CS), HS fed basal diet plus 4% Moringa (HS+M), ECP +CS, and ECP+Moringa (ECP+M; n = 12/treatment). Milk was collected on days 0, 3, and 14 of lactation to respectively represent colostrum, transitional, and mature milk. Lipids were extracted using the Bligh and Dyer method and analyzed using multiple reaction monitoring profiling. Statistical analysis was performed using MetaboAnalyst 6.0. Parity and day significantly affected milk lipid profiles, altering chain lengths and unsaturation number in a manner that potentially reflected differences in lipid mobilization between primiparous and multiparous sows. Independent of day and parity effects, ECP and diet also influenced the milk lipid profile. ECP increased the proportion of longer-chain triacylglycerols (TG), indicating protection against oxidative damage related to HS. Moringa increased fatty acid chain length and unsaturation on diacylglycerides (DG) with 25 carbons and 4 unsaturated bonds (25:4) as well as 26:11, 25:5, and 20:7, indicating Moringa supplementation potentially increased flavonoids, polyphenols, and other plant lipids that may function as antioxidants. Supplementing diets with Moringa and conductively cooling sows exposed to a HS environment altered lipid profiles of milk in a manner that supports incorporation of plant lipids into milk fat that function as antioxidants, and a decrease in oxidative damage to lipids, which may affect the overall quality of milk neonates receive in terms of nutrition and bioactivity.