High Levels of Grass Silage for Milk Production with No Grain, Medium, and High Grain Feeding. 1. Intake, Milk Production, and Body Weight Changes

A three-lactation study with 18 Holstein and six Guernsey cows compared roughage intake, milk production, and weight changes on three levels of grain feeding (no grain, medium grain--l:6, and high grain--l:3) with maximmn molasses-grass silage intake in addition to 5 lb. good alfalfa hay. Pasture was supplied during the summer. For each pound of grain fed, roughage dry matter intake decreased 0.23 lb. Average hay equivalent intake was 2.15 lb. over all groups. Average 245-day 4% FCM production for 12 cows with an estimated potential of 8,830 lb. was 6,490, 7,690, and 8,910 lb. on the three rations; for 12 cows with an estimated potential of 10,930 lb., production on the three rations was 8,080, 10,100, and 12,960 lb., respectively. There was no evidence of carry-over effects in the reversal phase or cumulative effects in the continuous phase. There was a close relationship between potential producing ability of the cows and response, measured as the ratio of extra milk produced per pound of grain fed, comparing production on high grain with that on no grain (r = 0.88).