Dietary sodium bicarbonate for high-producing Holstein cows over complete lactations

Several concentrates with sodium bicarbonate (experimental) were compared with the same concentrates without sodium bicarbonate (control) throughout two lactations. During first lactation, two control concentrates were used in sequence in one comparison and three in another. Toward the end of first lactation, sodium bicarbonate was increased from 1.5 to 2.5% in concentrates, and that concentration was continued throughout the second lactation. During second lactation high-moisture corn with soybean meal was one concentrate; the other included half high-moisture barley and half dry corn and soybean meal. Fifty-two and 60 lactations of cows fed control and experimental rations contributed feed intake and production data. Ninety-four and 95 lactations of cows fed control or experimental rations contributed 305-day, mature-equivalent production data over three lactations. Inclusion of sodium bicarbonate in these rations had little effect on feed consumption, milk production, fat content of milk, efficiency of milk production, or change of body weight. The kind of concentrate did not alter the effect of sodium bicarbonate. Cows consuming control rations produced 8898 kg milk with 312 kg fat (305-day mature equivalent). Cows using bicarbonate produced 8972 kg milk with 312 kg fat.