The influence of slowly and rapidly degradable concentrate protein on a number of rumen parameters in dairy cattle.

Abstract

In 5 trials with Dutch Black Pied or Dutch Black Pied X Holstein-Friesian cows the effects of feeding concentrates with rapidly and slowly degradable protein on rumen values were investigated. Samples of rumen fluid were taken before and 45, 90, 135 and 180 min after the morning concentrate feed. Rumen pH was not affected by protein degradability. Rumen ammonia content was higher when easily degradable protein was given than when slowly degradable protein was given; peak concentration varied from 10 to 12.5 and from 4 to 8 mmol/litre, respectively. Maximum concentration of lactate was not influenced by protein degradability. Rumen content of volatile fatty acids increased more rapidly when the slowly degradable protein rather than when the rapidly degradable protein was given. At all sampling times the molar acetate:propionate ratio was higher after feeding on slowly degradable protein than after rapidly degradable protein. (Abstract retrieved from CAB Abstracts by CABI’s permission)