Voluntary feed intake and metabolism of sheep when lactic acid is administered in the feed or intraruminally

Abstract

AbstractFour sheep in a 4 × 4 Latin Square experiment were offered ad libitum grass meal pellets alone or supplemented with lactic acid at 600, 800 or 1000 mmol per kg dry matter (DM) intake, either mixed into the feed or continuously infused intraruminally for 6‐d periods. When added to the feed lactic acid did not significantly affect DM intake but when infused intraruminally it significantly reduced DM intake especially at the highest rate of infusion.In a second 4 × 4 Latin Square experiment, four sheep were offered ad libitum grass meal pellets alone or supplemented with lactic acid mixed into the pellets at 900, 1200 and 1500 mmol per kg DM for 15‐d periods. There was a small reduction in intake on the three lactic acid treatments but this was not significant.In a third experiment the effects of intraruminal infusion with lactic acid was studied further with four sheep which received infusions of lactic acid at a fixed daily rate of 40 mmol per kg W−0·75 per d or of an equal volume of distilled water for 3‐d periods while being offered grass meal pellets ad libitum. Infusion with lactic acid resulted in reduced DM intake but the effect was less consistent than in Experiment 1.In all three experiments lactic acid supplementation had little effect on the pH and total volatile fatty acid concentration of rumen