Recent progress of porcine milk components and mammary gland function

As the only nutritional source for newborn piglets,porcine colostrum and milk contain critical nutritional and immunological components including carbohydrates,lipids,and proteins(immunoglobulins).However,porcine milk composition is more complex than these three components.Recently,scientists identified additional and novel components of sow colostrum and milk,including exosomes,oligosaccharides,and bacteria,which possibly act as biological signals and modulate the intestinal environment and immune status in piglets and later in life.Evaluation of these nutritional and non-nutritional components in porcine milk will help better understand the nutritional and biological function of porcine colostrum and milk.Furthermore,some important functions of the porcine mammary gland have been reported in recent published literature.These preliminary studies hypothesized how glucose,amino acids,and fatty acids are transported from maternal blood to the porcine mammary gland for milk synthesis.Therefore,we summarized recent reports on sow milk composition and porcine mammary gland function in this review,with particular emphasis on macronutrient transfer and synthesis mechanisms,which might offer a possible approach for regulation of milk synthesis in the future.

Combined yeast culture and organic selenium supplementation during late gestation and lactation improve preweaning piglet performance by enhancing the antioxidant capacity and milk content in nutrient-restricted sows

This study was conducted to investigate the effects of dietary supplementation with yeast culture(YC)and organic selenium(Se)during late gestation and lactation on reproductive performance,milk quality,piglet preweaning performance,antioxidant capacity,and secretion of immunoglobulin in multiparous sows.A total of 160 healthy cross-bred sows(Landrace×Yorkshire,mean parity 4.1±0.3)were randomly assigned to 4 groups as follows:1)high nutrient(HN),3,420 kcal/kg digestible energy(DE)and 18.0%crude protein(CP);2)low nutrient(LN),3,240 kcal/kg DE and 16.0%CP;3)LN+YC,LN diet+10 g/kg YC;4)LN+YC+Se,LN diet+10 g/kg YC+organic Se(1 mg/kg Se).Feeding trials of sows started from d 85 of pregnancy to d 35 of lactation.Compared with sows in the LN group,sows fed the LN+YC+Se diet had greater litter weaning weight,average litter gain,and milk fat content(14-d and25-d milk)(P<0.05).The content of malonaldehyde(MDA)(colostrum and 14-d milk)was lesser,and the activity of glutathione peroxidase(GSH-Px)(colostrum and 25-d milk)was greater when sows were fed the LN+YC+Se diet,compared with sows fed the LN diet(P<0.05).Supplementation of YC and organic Se in the nutrient-restricted diet improved sows’reproductive performance and pig weaning body weight by enhancing the antioxidant capacity and fat content in milk.