Effect of Sodium Bicarbonate and of Roughage on Milk Yield and Milk Composition of Goats and on Rumen Fermentation of Sheep

Abstract

Forty Damascus dairy goats and 12 Chios wether sheep were used to assess effects of sodium bicarbonate and roughage on milk yield and milk composition of Damascus goats and rumen fermentation and apparent digestion coefficients of Chios wether sheep. Addition of sodium bicarbonate increased apparent digestiblity coefficients of dry matter, organic matter, gross energy and of crude fiber on low roughage diet only. Wethers on diets supplemented with sodium bicarbonate gave higher urinary Na output. Water intake was correlated 0.62 with volume of urine, 0.58 with urinary Na output and 0.61 with dry matter intake. Roughage was more efficient than bicarbonate in elevating rumen pH, isovalerate and acetate molar proportions. Sodium bicarbonate increased acetate and reduced propionate molar proportion. There were no significant differences among diets in rumen ammonia nitrogen concentration. High roughage decreased live-weight gain. Neither bicarbonate nor roughage had a significant effect on conversion efficiencies of dry matter to milk and fat-corrected milk. The sodium bicarbonate diet proved acceptable to the animals. Absolute and fat-corrected milk yields were not affected, but the bicarbonate diet caused an increase in fat content and total solids content of milk.