Effect of Feeding Sodium and Potassium Bicarbonate on Milk Fat, Rumen pH, and Volatile Fatty Acid Production

Open Access
Publisher Website
Google Scholar
Abstract
Two groups of 6 Holsteins each were used in a double reversal trial with 3 periods of 21 days each. Milk production and milk fat was determined for the last 12 days of each period using daily milk weights and 3 day composites for Babcock analysis. All cows were offered 24 lb. of grain mixture composed of 77.5% ground corn, 20% soybean oil meal, 2.5% minerals and vitamins A and D plus 2 lb. of alfalfa hay per day. One pound of sodium bicarbonate was mixed with the grain ration at the time of feeding for the treatment group. In a 2d, trial, 3 groups of 3 cows each were used with three 21 day periods. The 3 treatments were 1 lb. sodium bicarbonate daily, 1 lb. potassium bicarbonate daily, and control. Two lb. of dehydrated alfalfa pellets replaced the 2 lb. of hay. Three mature, non-lactating Holstein cows equipped with rumen fistulas were fed rations of: (A) 12 lb. alfalfa hay and 8 lb. of grain, (B) 14 lb. grain plus 1 lb. alfalfa pellets; (C) treatment B plus 1 lb. sodium bicarbonate. Cows were rotated during the 3 periods so that each cow received each ration. Rumen samples were collected 3 hr. after feeding on the last 2 days of each 14 day period. Mild bloat occurred in both groups, but seemed to be aggravated by the sodium bicarbonate. Feeding sodium bicarbonate increased the milk fat percentage by 0.28 units in experiment 1 while sodium and potassium bicarbonate increased the milk fat percentage in experiment 2 by 0.8 and 0.5 units. Sodium bicarbonate feeding increased the rumen pH but had little or no effect on organic acid composition.