EFFECT OF SUPPLEMENTATION ON RUMEN MICROBIAL-POPULATION OF BULLS CONSUMING RESIDUES FROM THE SUGAR-CANE CLEANING CENTERS

Four Holstein rumen cannulated bulls, stabulated in a sugar cane clean ing centre, were used during the dry season for learning the effect of residues of cleaning centres (RCC) on the ruminal microbial populatio n and studying the effect of supplementation on the main physiological groups of bacteria and protozoa genera. Treatments compared were: A)R CC and B)RCC + protein-energy supplement. Ruminal liquor samplings wer e carried out at 0, 2, 4, and 6 hr after feeding. Experimental results were analysed according to a linear hierarchical model. The model con trolled the effects of treatments, animals within treatments, time and the treatment x time interaction. Supplementation significantly incre ased (P < 0.001) the total microbial population in the rumen. The cell ulolytic bacteria were 13.4 and 24.6 x 10(-6) cfu/ml for A and B, resp ectively. Proteolytic and amylolytic bacteria were significantly less numerous (P < 0.001) when there was no supplementation. The post-prand ial time had a significant (P < 0.001) effect on the predominance of t he different microbial group and the ruminal ecology of the animals fe d RCC, regardless the supplementation. It is concluded that it is nece ssary to include protein-energy supplementation in stabulated animals in the sugar cane cleaning centres for guaranteeing an increase in the population of cellulolytic bacteria.