摘要
Abstract
[Objectives]The differences in the quality of colostrum,milk production performance,and peri-natal physiology of dairy cows under different calving seasons were analyzed to provide reference for develop-ing seasonal schemes of feeding management.[Methods]120 dairy cows selected from a large-scale pasture were divided into four groups including spring group,summer group,autumn group,and winter group based on the calving season,with 30 dairy cows in each group.The physicochemical indexes of colostrum,content of im-munoglobulin G(IgG),milk production performance at 100 days postpartum,and physiological indexes related to metabolism and health of dairy cows during the perinatal period were measured under the unified conditions of feeding.The occurrence of perinatal diseases was recorded.The differences between different seasonal groups were compared with analysis of variance(AOV).[Results]There were significant differences in the qual-ity of colostrum,production performance,and physiological indexes among dairy cows in different groups.In terms of the quality of colostrum,the winter group had the best overall nutritional status and content of IgG(75.63 g/L),while the summer group had lower nutritional indexes and content of IgG(61.84 g/L)than other groups,with the proportion of individuals having low immune colostrum in summer group up to 21.67%.The cumulative milk production(3 387.46 kg)at 100 days postpartum in the winter group was significantly higher than that in other groups,with that in the summer group being the lowest(2 964.28 kg).In terms of physiologi-cal indexes,the indexes of metabolism,stress,and inflammatory in summer group were significantly higher than those in other groups,with the highest incidence of ketosis and uterine inflammation of 23.33%and 16.67%,respectively.[Conclusions]The effects of calving season on the quality of colostrum,milk production performance,and perinatal metabolic status of dairy cows were significant.Targeted measures of seasonal man-agement should be implemented to ensure the stable production performance in dairy cows.关键词
奶牛/产犊季节/初乳品质/免疫球蛋白/产奶性能/围产期代谢Key words
dairy cows/calving season/colostrum quality/immunoglobulin/milk production perfor-mance/perinatal metabolism
