| Abstract: | Buffer mainly consisting of 100 g of sodium bicarbonate and 30 g of magnesium oxide was added to the feed per head per day and given for 8 months to groups of 92 cows of milk fat depression. Milk fat increased from 3.06% (pre-treatment) to 3.68% at 4 months and 3.71% at 8 months post-treatment. Solids-not-fat was slightly increased by the buffers. Milk production was not affected. The number of rumen protozoa increased from 2.85 X 10(5)/ml (pre-treatment) to 9.61 X 10(5)/ml at 8 months post-treatment and the kinds of protozoa diversified. An increase of acetate and decrease of propionate were observed together with increased milk fat at 8 months post-treatment. An increase of hematocrit, lactate dehydrogenase, sodium and potassium, and a decrease of cholesterol and gamma-glutamyl transpeptidase in blood were recognized after the treatment. The incidence of disease was reduced. There was a significant correlation between increased milk fat percentage and increase in the number and the kinds of protozoa. |
