Einfluß von Harnstoff, Azetamid und Azetylharnstoff auf die freien Aminosäuren des Blutplasmas und die Aminosäurenzusammensetzung der Pansenproteine beim Schaf

Presence of Acetamide in Milk and Beef from Cattle Consuming AFEX-Treated Crop Residues

“…Rumen adaptation to the presence of nitrate in feed has been well studied, as have the underlying change in microbial flora and enzyme expression . It is well known that some microorganisms express acetamidase enzymes that metabolize acetamide into acetate and ammonia, suggesting that acetamide can be utilized by ruminants as a nitrogen source. , In Trials 1 and 2, the high AFEX treatment strongly outperformed the urea-supplemented straw in total energy output, even though this treatment would be nitrogen deficient if the acetamide was not being used as a nitrogen source . It is likely that acetamidase production is being increased in the rumen during this transient adaptation period, either by a change in subpopulations in the rumen microflora or by a change in acetamidase expression levels.…”

“…Acetamide has been classified as a possible human carcinogen; rats fed acetamide at 2.36% of their diet for 12 months produced liver carcinomas . While acetamide can be metabolized in the rumen by amidase enzymes into acetate and ammonium, − any acetamide that is not metabolized in the rumen could enter the milk or meat, in which case the feed contaminant would also become a food contaminant. Previous research suggests that acetamide can pass through the rumen wall and thus may enter the bloodstream.…”