Effects of fumaric acid on rumen fermentation, milk composition and metabolic parameters in lactating cows.
The aim of this study was to determine the influence of fumaric acid (FA) on ruminal fermentation and its effects on the acid-base balance of seven ruminally and duodenally fistulated multiparous German Holstein cows. The experiment was conducted in a change-over design with three periods in which the animals were randomly arranged in one of three treatments: Control (C; without FA), 300 or 600 g FA per day. The diets consisted of 7.4 kg DM grass silage, 4.2 kg concentrate mixture and 0, 300 or 600 g FA or wheat starch as isocaloric compensation per day and cow. FA supplementation decreased the rumen pH, acetic acid and butyric acid and increased propionic acid in rumen fluid. The results of the single-strand conformation polymorphism analysis (SSCP) did not show an influence of FA on the microbial population in the rumen. The beta-hydroxybutyrate (BHB) concentration in blood and the pH of the urine decreased, while the blood gases were unaffected by supplementation of the acid. The microbial protein per MJ ME decreased in the duodenum with FA supplementation. The milk fat concentration decreased after addition of FA. We conclude that in this study feeding of up to 600 g FA per day did not result in an acidosis. It seems that up to 600 g FA per day did not have a significant influence on the acid-base balance of dairy cows.
['Remling|N|N|', 'Riede|S|S|', 'Lebzien|P|P|', 'Meyer|U|U|', 'Höltershinken|M|M|', 'Kersten|S|S|', 'Breves|G|G|', 'Flachowsky|G|G|', 'Dänicke|S|S|']
D000821:Animal Feed D000824:Animal Nutritional Physiological Phenomena D000818:Animals D001105:Archaea D001419:Bacteria D002417:Cattle D018592:Cross-Over Studies D004032:Diet D004734:Energy Metabolism D005260:Female D005285:Fermentation D005650:Fumarates D007774:Lactation D008892:Milk D012417:Rumen
fumaric acid rumen fermentation lactating cows grass silage digestibility acid-base balance