A comparison of the nutritive value of roughage alone and of roughage plus a limited amount of concentrates for dairy cattle
Hodgson, R.E.; Knott, J.C.; Wolberg, F.B.
Rep. Wash. agric. Exp. Sta, 394, 39-40
To date 17 cows that have been fed on roughage alone from one year of age have completed 28 lactations. The roughages are good pasture, home-grown hay consisting of grasses and legumes, silage made from grass and legume mixtures, oats and peas and pea vines. Thirteen cows that have been fed from one year of age on the same kind of roughage plus a limited amount of grain (approximately 18 per cent. digestible crude protein) have completed 21 lactations.