Short-Interval Milking as a Physiological Technique. I. Effect of Frequent Milking with the Aid of Oxytocin on Milk and Milk Fat Production

Thirteen Holstein cows at various stages of lactation and levels of production were milked at 2-hr.intervals with the aid of oxytocin.It was shown that the average daily milk production was increased and that the fat per cent in milk was reduced for the high producers (average daily production: 60.6 lb.milk) during the 2-hr.milking.Following return to twice-a-day milking, the milk production returned to normal, but there was an over-compensatory increase in fat per cent.The moderate producers among the cows (average daily production 39-43 lb.milk) did not show any significant changes in milk production, fat production, or fat per cent.It is concluded that the rate of milk secretion is not altered significantly for moderate producers on changing from twice-daily milking to 2-hr.milking for short total periods.The response of the high producers is explained on the basis of the effects of intramammary pressure on fat uptake by the mammary gland and on the rate of milk secretion.