INFLUENCE OF RUMEN CILIATE PROTOZOA AND PROTEIN LEVEL ON RUMEN FERMENTATION, ENZYME-ACTIVITIES AND BLOOD METABOLITES IN CROSSBRED CATTLE CALVES

The influence of ciliate protozoa in the rumen on fermentation and enz yme activities in rumen fluid and blood metabolites of crossbred (Bos taurus X Bos indicus) cattle calves was studied in animals fed at two levels of protein. Sixteen crossbred male calves, separated from their dams at 24h to 48h of birth, were divided into two groups faunated an d defaunated and given a diet of normal protein or lower protein (75% of the requirement). The calves were reared in isolation stalls to avo id contact with faunated calves. On 3 months of age ruminal contents f rom all calves were collected at 4h post feeding and analysed. The pH, total volatile fatty acids (TVFA), carboxymethylcellulase (CMC), xyla nase and protease activities were similar in both faunated and fauna-f ree calves. Ammonia-nitrogen, TCA-soluble nitrogen, the urease activit y, plasma protein and urea bevels were significantly lower in ciliate- free animals than those in faunated animals, whereas, plasma glucose l evel was significantly higher in defaunated animals. Blood haemoglobin level teas not affected either by the presence or absence of protozoa or by the protein level in the diet. The results of the present exper iment indicate that the rumen ciliate protozoa affect the nitrogen met abolism of the rumen microbes considerably.