YIELD AND NUTRITIVE VALUE OF CORN, BARLEY, WHEAT, AND FORAGE OATS AS SILAGE FOR LACTATING DAIRY COWS

Abstract

Whole crops of corn, barley, wheat, and forage oats were ensiled and fed as the sole forage to 48 milking cows in two 12-wk feeding trials. In the first experiment corn (25.1% dry matter (DM)) harvested in the early dent stage, barley (34.2% DM), and forage oats (27.6% DM) harvested in the dough stage were compared. Holstein cows fed the three silages averaged 22.6, 19.7, and 18.7 kg of 4% fat-corrected milk per day and consumed 1.67, 1.82, and 1.85 kg of silage DM per 100 kg body weight, respectively. In the second experiment, cows fed wheat (35.7% DM), barley (29.8% DM), or forage oat (27.0% DM) silage harvested in the dough stage produced 21.2, 23.3, and 22.1 kg fat-corrected milk daily and consumed 1.75, 1.71, and 1.62 kg silage DM per 100 kg body weight, respectively. Corn silage DM intake was lower (P < 0.01) but more efficiently utilized for milk production (P < 0.01) than barley or forage oats, whereas wheat, barley, and forage oat silages were similar in feeding value. In experiment I, rumen acetate increased and butyrate decreased with corresponding increases in forage fiber content. Propionate levels were unaffected by the kind of forage, whereas blood urea nitrogen was highest for cows fed forage oats in both experiments.