CHANGES WITHIN THE DIGESTIVE-TRACT OF SHEEP FOLLOWING ENGORGEMENT WITH BARLEY

The effect of feeding 1.4 kg of barley on the amount and composition o f digesta in the rumen, small intestine, caecum, and colon was measure d in sheep given either a gradual introduction to barley (over 8 days) , no introduction, Yea Sacc (4 g/day for 9 days), virginiamycin (30 mg /day for 4 days) or rumen inoculum (600 mL/day for 4 days). The rumen pH was higher (P < 0.05) and the number of sheep with high (> 5 mmol/L ) levels of L-lactate and D-lactate significantly lower (P < 0.05) in sheep receiving no introduction compared to sheep receiving the gradua l introduction to barley. Conversely the pH was lower (P < 0.05) and t he molar proportion of L-lactate higher (P < 0.001) In the caecum of t he sheep receiving no introduction compared to sheep receiving the gra dual introduction to barley. There was no difference (P > 0.05) in the incidence of ruminitis between treatment groups. Both virginiamycin a nd the transfer of rumen fluid from well adapted animals appeared to b e as effective as the gradual introduction of barley in controlling L- lactate accumulation in the caecum and colon and maintaining the pH wi thin these organs. The probiotic Yea Sacc did not appear to cause any changes in the pattern of fermentation and digestion when compared to the untreated control animals.