[Experimental studies of the pathogenesis of rumen acidosis in sheep]

Rumen acidosis was provoked in 13 cross-bred sheep by feeding oat (32 g/kg body weight) or wheat of different grinding levels (26 g/kg). Development of the diet-related disease was studied in 8 fistulated sheep fitted with a permanent rumen cannula and with implanted jugular vein catheter by analysing blood and rumen fluid sampled up to 48 hours after feed intake. Ingesta of the different segments of the digestive tract were collected from 5 sheep, necropsied 8 and 12 hours after feeding respectively. Concentrations of glucose, L- and D-lactate were measured in blood and digesta by enzymatic methods. Concentrations of amylopolyglucans and pH values were analysed in the digesta. Whereas the plasma concentration of glucose and L-lactate rose with a maximum at 8 to 12 hours after feeding, that of D-lactate was maximally increased after 24 hours. High concentrations of amylopolyglucans, glucose, L- and D-Lactate were found in the whole digestive tract 8 and 12 hours after feed intake. It is concluded from the results obtained that sheep show characteristics of monogastric intestinal digestion with the release of considerable amounts of glucose and of both lactate isomers after feeding fine distributed starch.