Effects of sodium sesquicarbonate on dry matter intake and production of milk and milk components by Holstein cows

Forty-six multiparous Holstein cows were used to investigate the effects of sodium sesquicarbonate on dry matter intake, body weight, and production and composition of milk during a 308-d lactation. Diets contained alfalfa silage, corn silage, and concentrate. Composition of diets was changed twice during the 308-d lactation experiment. Diets fed during d 1 to 175 and d 176 to 245 were formulated to contain more rumen-undegradable protein and fat, and less forage than that fed during d 246 to 308. Sodium sesquicarbonate did not affect yields of milk, 4% fat-corrected milk, and components in milk, or percentages of components in milk during the complete 308-d lactation or during d 1 to 175 or d 176 to 245. However, from d 246 to 308, cows fed sodium sesquicarbonate produced more milk, 4% fat-corrected milk, fat, protein, and solids-not-fat than did control cows. Milk composition was not altered. These data suggest that composition of the diet has a significant effect on the response to dietary buffers by lactating dairy cows.