The examination of 108 first year seeds hays showed the average crude protein content to be 9·0 ― and the average crude fibre content 25·7 ―. The crude protein content varied from 5·0 to 13·5 ― and was directly associated with the clover content.Figures obtained on hays cut in the second and third years of the ley suggest that the protein content falls, and the crude fibre content rises, with increasing age of ley.The composition and digestibility of twenty first year hays were determined and the average figures quoted for hays of high, medium and low clover content. The starch equivalent values of these hays were high and moderately constant, varying from 33·3 to 41·2, average 36·8. The protein equivalent values varied from 1·8 to 8·4 ―, average 5·1 ―.The composition and digestibility of four samples of second year seeds hay, two samples of third year hay, one sample of second cut hay in its first year and one sample of lucerne and cocksfoot hay were also determined.