Study On Seasonal Variation Characteristics Of Milk Yield And Raw Milk Composition Of Baotou Holstein Cow

This study by tidying up the date that the seasonal change in milk yield and milk composition in Baotou’s KaiYuan ranch from2007to2013, to analyze the seasonal change in milk yield,4%milk production, ECSM and milk composition, And to further explore the effects of temperature on milk yield and milk composition, to provide scientific basis for improving pasture production levels.The results show:(1) Milk yield while there are some differences due to the annual changes in climate temperature, but roughly the same trend. Every spring in March began to rise (bimonthly significant difference between P<0.05) and to the highest from May to August, in September began to decline (significant difference between adjacent months P<0.05) from October to February to a minimum.(2) Every year, a significant milk composition variation, especially milk fat, milk protein and milk energy content. In February began to rise (bimonthly significant difference between P<0.05)and to May-August peak, began to decline in September (a significant difference between adjacent monthly P<0.05) from October to January to the lowest.(3) No significant production of milk composition differences, but lower production volume during the cold season(4) Temperatures have an impact on milk production, and the effect of cold temperatures on milk production season is greater than the impact of spring temperatures on milk production.(5) The4%standard milk and milk energy corrected milk yield trends standard is consistent with the trend of milk, but milk production is less than the magnitude of the change; when high percentages of milk components, the change of the magnitude of the differences among the three not significant, when the low percentage of milk components, the change is much greater than the magnitude of the milk yield of4%fat corrected milk and milk energy calibration standards.Conclusion:The annual milk yield Baotou basically the same variation. The milk protein, milk fat and milk energy content have significant variation each year. Part of the milk is the amount of change and the dilution effect of concentrated milk caused.