Depression of ruminal digestion in adult sheep by aureomycin.

Abstract

After the consumption by adult sheep of an amount of aureomycin hydrochloride corresponding to 23.6-27.1 mg. per kg. body weight, the ruminal flora had fallen about 75 per cent. within two hours and remained a t this low level for at least two days, the survivors being predominantly Gram-positive rods and cocci. Ruminal fermentation was greatly depressed; the yield of organic acids reached only about 30 per cent. of the normal and was insufficient to lower the ruminal pH significantly. Appetite was lessened and body weight fell, but responded favourably to administration of ruminal fluid and yeast extract.