The colostrum chronicles: identifying porcine milk oligosaccharides in colostrum and investigating their role in litter performance.

Abstract

In commercial pig production, sows have been selectively bred to become hyper-prolific. However, litter size is positively associated with pre-weaning mortality rate, often due to factors, such as intrauterine growth restriction, limited teat availability, and unequal access to colostrum. Colostrum plays a critical role in neonatal survival, providing not only passive immunity but also bioactive compounds such as porcine milk oligosaccharides (PMO), which exhibit prebiotic and immunomodulatory properties. While human milk oligosaccharides have been successfully added to infant formula, the potential application of PMO in piglet milk replacers remains underexplored. This study aimed to characterize PMO in colostrum from 45 hyper-prolific Large White × Landrace sows (parity 2-8) and investigate their associations with litter performance metrics, including pre-weaning mortality and piglet body weight. Colostrum was sampled and pooled from multiple teats per sow at the on-set of farrowing. Using LC-MS/MS, 11 PMO structures were identified and analyzed via mixed regression models. Litter size was a significant but modest predictor of lacto-N-neotetraose (LNnT) concentration (R2 = 0.198; P = 0.0143), with concentration decreasing as litter size increased. Higher concentrations of 2'fucosyllactose (2'FL) appeared to reduce the pre-weaning mortality rate, although the significance of this diminished after false discovery rate adjustment. Despite this, our findings suggest that specific PMO play a role in early litter performance. Despite all sows being managed within the same herd, with similar genetics, there was considerable inter-sow variation in colostrum composition. Further research is needed to assess whether supplementing piglet diets with targeted PMO could enhance outcomes in large litters, where competition may render natural concentrations insufficient to exert measurable effects. In modern pig farming, sows have been bred to produce very large litters. While this increases productivity, it also leads to more piglet losses. This is often due to restricted growth in the womb and/or limited access to colostrum, the first secretion from the mammary gland. A vital component of colostrum is complex sugars, such as porcine milk oligosaccharides (PMO), which support gut health and immunity. Human milk oligosaccharides are already added to infant formula to promote healthy development, but PMO are not yet used in piglet milk replacers. This study looked at colostrum from 45 highly productive sows to explore whether PMO were linked to piglet survival and growth. Using advanced spectroscopy and chromatography analysis, we identified 11 PMO structures. We found that a specific PMO, 2′-fucosyllactose (2′FL), was possibly associated with lower piglet mortality, and another compound, lacto-N-neotetraose (LNnT), changed with the number of piglets born, suggesting mothers may adjust colostrum composition with litter size. Although we saw only weak links between PMO and piglet bodyweights, our findings suggest that some PMO may support early piglet health. Further research could explore whether adding PMO to piglet formulas, as has been done with humans, might improve survival in large litters.