The concentration of fat, protein and lactose in sows' colostrum from sucked and unsucked glands during lactogenesis II

Abstract

The relationship between the changes in the composition of colostrum and the removal of colostrum from individual glands during lactogenesis II in the sow was investigated. Sequential samples of colostrum were collected from all mammary glands on six sows during the farrowing period, and the amount of colostrum removed from each gland was measured by weighing the piglets at 15 min intervals. Prior to farrowing, there were large between sow variations in colostral fat (c.v. 39.8%) and protein (c.v. 22.9%) compared with lactose (c.v. 9.5%), but less within sow variations for these components (< 13.2%). From the commencement of farrowing, the sucked glands of all sows showed a significant increase in the concentration of colostral fat from 45.2 g/L to 76.1 g/L, but no consistent significant changes in the concentration of protein and lactose. The unsucked glands of all sows showed no consistent significant changes for fat, protein or lactose. Analysis of individual glands showed that 27 of the 34 sucked glands had a positive correlation between fat concentration and amount of colostrum removed. It was concluded that the withdrawal of colostrum from the mammary glands is an important component in the progressive increase in colostral fat during lactogenesis II in the sow.