Published online by Cambridge University Press: 27 March 2009
An experiment was carried out with two groups of ten cows each, made up of two Guernseys, two Ayrshires, two Friesians and four Shorthorns.
The experiment was of the change-over type, the experimental period of 20 weeks being subdivided into four periods of 5 weeks, each cow alternating between the two treatments.
In two of the periods a normal winter ration of roots, hay and concentrates was fed. In the other two periods artificially dried grass replaced a proportion of the concentrates, an average of 8 lb. being fed per head daily. The two types of ration provided equal amounts of starch equivalent and protein equivalent, but the carotene intake was greater in the “dried grass ration”.
A statistical analysis of the difference in milk yields due to the contrast “Dried grass” v. “Control” revealed no signs of any effect, and if any actual effect does exist, it is quite negligible for the 5-week periods of this experiment.