Small metabolites vary in sow milk across the course of lactation, while moringa supplementation and cooling sows exposed to heat stress conditions have limited effects.

This study investigated how the small molecule composition of pig milk changes during the three phases of lactation, and whether adding moringa leaf powder to the diet or using electronic cooling pads could improve milk quality in heat-stressed sows. Researchers followed 48 Yorkshire x Landrace sows from late pregnancy through three weeks of nursing, collecting milk samples at birth (colostrum), day 3 (transitional milk), and day 14 (mature milk). They used advanced metabolite profiling techniques to identify and measure hundreds of small molecules in the milk samples. The study found dramatic changes in milk composition across lactation phases, with 55 metabolites increasing and 93 decreasing between colostrum and transitional milk, reflecting shifts in metabolic pathways related to amino acid production and energy metabolism. Between transitional and mature milk, 148 metabolites increased while 21 decreased, showing continued adaptation to piglet needs. Surprisingly, moringa supplementation had minimal impact on milk metabolite profiles, with effects mainly seen in colostrum and influenced by whether sows had given birth before. Electronic cooling pads showed some effect on day 3 milk composition, reducing 104 metabolites involved in energy production pathways. The research demonstrates that sow milk composition is highly dynamic and responds to the changing nutritional requirements of growing piglets, though environmental and dietary interventions showed limited ability to modify this natural process.