679. The relationship between milking rate and milk yield

This paper deals with an investigation on the influence of milking characteristics on lactation yield, maximum daily yield, and persistency carried out at the Institute of Animal Breeding and Genetics at the Agricultural College of Norway. Data used for the analyses were collected from 57 heifers of Norwegian Red Poll and 111 heifers of Norwegian Red and White Cattle. The Red Polls were recorded at the Hafslund Progeny Testing Station, while the recording of the Reds and Whites were carried out by field control. When the effect of the milk yield at the recorded milkings on the observed milking characteristics was eliminated, the milking character had no significant effect on the lactation yield, the maximum daily yield, or the persistency. This was the case when the effect of the milk yield at the recorded milkings was eliminated by correction as well as by using only those observations of milking characteristics that were taken when the milk yield was between 6·1 and 7·0 kg. Slow-milking cows are not, therefore, necessarily poor milk producers.