Cecal Microflora of Turkeys Fed Low or High Fiber Diets: Enumeration, Identification, and Determination of Cellulolytic Activity

Examination of cecal contents or bacterial cultures thereof from turkeys fed either a high fiber (HF) or low fiber (LF) ration indicated that direct microscopic counts of microbes were significantly higher in HF-fed than in LF-fed birds. There was no significant difference in mean colony counts between the two groups of turkeys. In both LF and HF-fed birds, 77% of the microbes were Gram-positive rods, 14% Gram-negative rods, and 9% Gram-positive cocci. The predominant microorganism was Eubacterium, but Lactobacillus, Peptostreptococcus, Escherichia coli, Propionibacterium, and Bacteriodes were also isolated. Percentages of Peptostreptococcus were significantly greater in HF-fed turkeys and of E. coli were significantly greater in LF-fed turkeys. Yeasts were routinely found in both LF and HF-fed birds, but protozoa were not isolated. Turkeys fed the HF diet harbored significantly higher numbers of facultative microorganisms than did LF-fed birds. In pure cultures from turkeys preconditioned to a HF diet, there was a nonsignificant trend toward greater cellulolysis than in pure cultures from LF-fed turkeys. In contrast, cellulolysis by mixed cultures from HF-fed birds was significantly greater than that in mixed cultures from LF-fed turkeys.