Abstract: The experiment was conducted to investigate the effects of NDF levers in diet on the community structure and the grazing rate of ruminal protozoa by Fluorescence-Labeled Bacteria (FLB) technique. Four Xuhuai goats with permanent cannulas were used in a 4x4 Latin squares and diets were divided into A (54.87%), B (44.23%), C (33.72%) and D (23.23%), on the basis of NDF content in diet. The research results showed that the NDF content in diet had a profound influence on the rumen fermentation and subsequently modified the structure and the grazing rate of protozoa. Percentages of Entodiniinae and Isotrichidae were much higher in group C and D, whose diets containing low NDF content, the reverse was true for Diplodiniinae or Ophryoscolecinae, their proportions were higher in group A and B, whose diets containing high NDF content while, Entodiniinae was the dominant population of protozoa in the rumen. Furthermore, significant differences were found in protozoa grazing rates between groups and the lowest rates (366.7 cells h-1) falling in group B containing 44.23% NDF. And also, marked difference was found in the predation rates among genus and there were 361.9, 606.3 and 607.5 cells h-1, respectively for Entodiniinae, Diplodiniinae and Ophryoscolecinae and the grazing rate of Entodiniinae were significantly lower than those of both Diplodiniinae and Ophryoscolecinae. Community structure and grazing rate of rumen protozoa were modified by dietary NDF content.
M.Z. Wang, H.R. Wang and L.H. Yu, 2009. Effects of NDF Content on Protozoal Community and Grazing Rate in Rumen. Journal of Animal and Veterinary Advances, 8: 1746-1752.