OBSERVATIONS ON THE ETHANOL-METABOLISM OF RUMINANTS

Ethanol concentration of different fermented feeds was measured during in vitro and in vivo experiments, as well as data were collected for the ruminal and hepatic degradation of ethanol. More important finding s were, as follows: 1. On an average, 45.6+/-4.6 g/kg dry matter ethan ol was found by gas chromatography in the maize silages. That value wa s only one fifth in the alfalfa silages (Table 1). 1. In spite of the relatively high ethanol uptake with the conserved feeds, only low, alt ogether 12.2 mg/l ethanol concentration was measured in the ruminal ju ice five hours after feeding and it showed relatively high differences in animals with different stages of lactation (Table 2). Quick decomp osition of ethanol can possibly be explained with the intensive alcoho l decomposition capacity of ruminal juice which was also confirmed by the results of the in vitro experiment. 3. Alcohol dehydrogenase (ADH) activity, playing a key role in the decomposition of ethanol, could n ot be demonstrated in the ruminal epithelial cells of sheep investigat ing either mucosal scraping or cells of cell cultures. However, liver had a significantly high ADH activity (11 114+/-2731 nanokatal/mg prot ein). 4. Ethanol possibly has a local effect on the ruminal mucosa. Et hanol increased the cell multiplication in the primary ruminal epithel ial cell cultures (Figure). This raises the possibility that certain c oncentrations of ethanol participate in the adaptation processes of ru minal wall.