Some Effects of Seasonal Changes in Dairy Herd Management upon Milk Yields

Seasonal variations in the milk production of a dairy herd are due to the seasonal distribution of calvings, to changes in the potential productivity of the herd due to effects of age, and to seasonal changes in the herd environment. This is a preliminary report of an attempt to estimate the effect of these seasonal changes in climate, feeding and management upon milk yields during single herd years, by making adjustments for the effects of the calving distribution and changes in potential productivity. Milk records from two Dairy Shorthorn herds were used.