Effect of Feeding Different Ratios of Alfalfa Hay and Corn Silage with Similar NDF and Cation-Anion Balance in Lactating Dairy Cows

To determine the best ratios of alfalfa hay to corn silage with similar dietary NDF, cation-anion balance, energy and protein content in the lactating dairy cows, eight mid-lactating Holstein dairy cows with average body weight of 570 kg, and milk yield of 22 kg/d with 3.5% fat, were assigned to each of four experimental diets with alfalfa hay to corn silage ratios of 100:0, 67:33, 33:67 and 0:100., in a 4 × 4 Latin square design with two replicates. Dry matter intake, digestibility, rumen degradability of DM, fat percentage and total solids in milk for diets one to four were 19.09, 19.94, 20.94, 20.90 kg/d 69.07, 65.75, 71.78, 49.82% 52.8, 49.6, 50.4, 46.7% 3.47, 3.53, 3.79, 3.93% 12.17, 12.17, 12.48, 12.60%, respectively. Diets containing 67% silage showed the highest dry matter intake, 3.2% FCM and digestibility. Degradability in rumen were highest and lowest in diets containing 100% alfalfa hay or corn silage, respectively. Increased ratios of silage to alfalfa hay corresponded to increases in milk fat and protein yield, milk protein percentage and total solids in milk.