Changes within the digestive tract of sheep following engorgement with barley

Abstract

The effect of feeding 1.4 kg of barley on the amount and composition of digesta in the rumen, small intestine, caecum, and colon was measured 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 gradual introduction to barley. Conversely the pH was lower (P < 0.05) and the molar proportion of L-lactate higher ( P < 0.001) in the caecum of the sheep receiving no introduction compared to sheep receiving the gradual introduction to barley. There was no difference (P > 0.05) in the incidence of ruminitis between treatment groups. Both virginiamycin and the transfer of rumen fluid from well adapted animals appeared to be as effective as the gradual introduction of barley in controlling L-lactate accumulation in the caecum and colon and maintaining the pH within 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.