Effect of Sodium and Calcium Carbonates on Milk Production and Composition of Milk, Blood, and Rumen Contents of Cows Fed Grain Ad Libitum with Restricted Roughage

Abstract

Six cows were used in a Latin square design consisting of three periods of 28 days each and three treatments, grain plus sodium bicarbonate (1 lb/day), grain plus calcium carbonate (0.6 lb/day), and grain alone. Roughage was restricted to 2 lb hay/day and grain was fed ad libitum. Similarly, two groups of five cows each were used in a double-reversal trial consisting of three 28-day periods. Sodium bicarbonate plus grain and grain alone were the treatments. Sodium bicarbonate feeding increased milk fat concentration 0.81 and 0.86 percentage units in the two trials, whereas calcium carbonate feeding had no such effect. Treatments did not affect milk production or its content of solidsnot-fat and protein. Grain intake was depressed 10 to 20% by sodium bicarbonate feeding'. From 40 to 69% of the treatment effects on milk fat concentration could be explained by the proportions of rumen acetate and propionate. The concentrations of ketones, glucose, hydrogen ion, sodium ion, lipids, and lactic acid in blood were not closely related to sodium bicarbonate effects on milk fat concentration.