The Effect of Continuous Infusion of Volatile Fatty Acids into the Rumen on the Milk Composition Infusion of Mixed Fatty Acids

Abstract

Two lactating dairy cows were used to determine the effects of infusion of propionic acid mixed with acetic acid and/or butyric acid into the rumen on the milk composition, particularly on butterfat content. The trial consisted of 7 experimental periods. The treatments corresponding to the periods. were 1 & 7 water infusion, 2 & 6 propionic acid infusion (1500ml/day), 3 propionic acid (1000ml/day)+butyric acid (500ml/day) infusion, 4 propionic acid (1000ml/day) +acetic acid (500ml/day) infusion and 5 propionic acid (1000ml/day)+ acetic and butyric acids (250ml of each acid/day) infusion. The daily allotment of these acids was diluted in 40l of water for the continuous intraruminal infusion.
The propionic acid infusion decreased milk fat content and increased protein, casein and SNF content of milk. The supplement of acetic and butyric acids singly, or together, to propionic acid raised milk fat content, although it did not reach the level of the water infusion periods.