169. A statistical inquiry into the inheritance of milk yield in three herds of dairy Shorthorn cattle

Abstract

The paper embodies an examination of the possibility of sex-linked genes affecting the transmission of milk yield. To reduce environmental effect the study was restricted to three herds of the English Dairy Shorthorn breed, and each herd was considered as a unit. Fisher's Squared Difference method was used.The lumped results confirm previous work to the effect that the paternal grandsire has a lesser effect than the maternal grandsire. In this respect the figures for one herd did not agree with the other two.The largest herd (which showed this difference) was divided into two sections, high and low yielders. These sections did not show any difference in the relative effect of the two grandsires. The implications of this are discussed, and it is tentatively suggested that if sex-linkage operates it has a considerable effect of some 250 gallons on an average yield of 600 gallons.