Unidentified Dietary Factors in Dairy Cattle Nutrition. III. The Nutritive Value of Immature Alfalfa and Timothy Hays for Milk Production

Most of the information regarding the change in the nutritive value of legume and grass hays associated with the advance in maturity is based on chemical analyses and digestion trials. Woodman et al. (22) reported that all of the concentrates in the ration were satisfactorily replaced by immature grass for milk production. Newlander (18) replaced 5 lb. of hay with 4 lb. of artificially dried young grass in a ration which contained corn silage and grain and found that milk production was in favor of the young grass, although the number of pounds of fat-corrected milk (F.C.M.) per 100 lb. of total digestible nutrients (T.D.N.) was not altered significantly. Camburn (3) replaced the grain in a hay-corn silage-grain ration with young grass and found that when body weight and milk production were considered, the T.D.N. in dried grass were equal to or slightly better than the T.D.N. in the grain. Camburn (4) also replaced corn silage with soaked, artificially dried, immature grass in the ration of 10 cows during a ]2-wk. period and reported that milk production increased in eight of ten cows, but since there was an increased intake of T.D.N. during the grass-feeding periods, no significant difference was found in the nutrients required to produce a unit of 4 per cent F.C.iK. Camburn and Jones (5) reported further that the T.D.N. in artificially dried, immature forages were at least equal to the T.D.N. in grain for milk production when corn silage was in the ration.