Dynamic Analyses of Lactose and Milk Protein in Erhualian Sows and Their Comparisons with Yorkshire Sows

With Experiment Ⅰ and Ⅱ,lactose and milk protein in Erhualian and Yorkshire sows were investigated during lactation (1～21 d) after parturition;meanwhile,milk fat was determined in day 1 and 6～7 postpartum in Experiment Ⅱ.Lactose concentration in Erhualian and Yorkshire sows was lowest in colostrum (on day 1),then gradually increased as lactation progressed.Lactose concentration was much lower for Erhualian vs.Yorkshire sows in day 1,6～7 and 8～10 postpartum (p0 05 or p0 01) and trend to be lower in other lactation period.Milk protein concentration in Erhualian and Yorkshire sows was highest on day 1 postpartum,then sharply decreased during 7 d postpartum.Milk protein concentration in Erhualian and Yorkshire sows varied slightly in day 8～21 postpartum.However,the significant difference in milk protein between Erhualian and Yorkshire sows was not observed (p0 05).Lactose and protein in sow milk were negative correlation.Correlation coefficients (r) in Erhualian and Yorkshire sows were -0 703 (p0 01) and -0 577 (p0 01) respectively.Milk fat concentration in Erhualian sows was significantly higher than that in Yorkshire sows in day 0～1 and 6～7 postpartum (p0 05).