The effect of unequal intervals between milkings upon milk production and diurnal variation in milk secretion.

Abstract

Five pairs of twin heifers were milked twice daily at intervals of either 11 and 13 hr or 8 and 16 hr for a period of 16 weeks. Total milk and fat production were recorded and, from determinations of residual milk, secretion rates during each interval were estimated. Total milk production was slightly, not significantly, higher in the group subjected to unequal intervals. It was estimated that any depression of production due to intervals even as widely disparate as these is likely to be very small. Fat percentage was unaffected by treatment. Evidence of diurnal variation in milk or fat secretion under the influence of a schedule of 8 and 16-hr intervals was not conclusive, but overall there was no significant evidence that secretion rates were lower during the longer interval.