[Objective] The paper was to test the effects of polyacrylamide(PAM) on ruminal microbial flora, activities of fibre-degrading enzymes and voluntary feed intake(VFI) of sheep. [Method] Five of 2-3 years old male Small...[Objective] The paper was to test the effects of polyacrylamide(PAM) on ruminal microbial flora, activities of fibre-degrading enzymes and voluntary feed intake(VFI) of sheep. [Method] Five of 2-3 years old male Small-tail Han sheep, with body weight of(51.5±4.1) kg and fitted with permanent rumen fistula were used. By a 5×5 Latin square design, sheep were fed a basal diet supplemented with PAM at 0(control), 1.0, 2.0,3.0 and 6.0 g/kg diet, respectively. [Result] PAM supplementation affected VFI and ruminal indexes, and the peak values of them were at 2.0 g/kg diet by 17.9% for VFI, 56.6% for total bacteria, 18.3% for endocellulase, 19.4% for exocellulase and 16.5% for cellubiase( all P<0.05), respectively,compared with control. The NH3-N, protozoal counts, and the protease activity in rumen fluid were all linearly declined, but fungal counts increased linearly. No significant changes were found in pH, activities of xylanase and amylase of rumen fluid. The PCR copies of Fibrobacter succinogenes,Ruminococcus albus, Butyrivibrio fibrisolven and Selenomonas ruminantium increased to maximum of 21.4%, 22.7%, 22.6% and 20.6%(all above P<0.05), whereas these of Prevotella bryantii, Clostridium aminophilum, methanogens and microscopic counting of great coli decreased to maximum of 24.5%, 34.8%, 21.2% and 52.2%(all above P<0.05);but Salmonella bovis and Prevotella ruminicola were not affected by PAM. [Conclusion]PAM supplementation at 2.0 g/kg diet can reduce protozoa but increase bacteria, particularly those species for fibre digestion, and fungi in rumen.The effect of PAM on bacterial species was selective. These changes finally enhanced activities of enzymes for fibre digestion in rumen, and stimu-lated VFI of sheep, suggesting a potential application of PAM in ruminant production.展开更多
基金Supported by National Natural Science Foundation of China(31772625)。
文摘[Objective] The paper was to test the effects of polyacrylamide(PAM) on ruminal microbial flora, activities of fibre-degrading enzymes and voluntary feed intake(VFI) of sheep. [Method] Five of 2-3 years old male Small-tail Han sheep, with body weight of(51.5±4.1) kg and fitted with permanent rumen fistula were used. By a 5×5 Latin square design, sheep were fed a basal diet supplemented with PAM at 0(control), 1.0, 2.0,3.0 and 6.0 g/kg diet, respectively. [Result] PAM supplementation affected VFI and ruminal indexes, and the peak values of them were at 2.0 g/kg diet by 17.9% for VFI, 56.6% for total bacteria, 18.3% for endocellulase, 19.4% for exocellulase and 16.5% for cellubiase( all P<0.05), respectively,compared with control. The NH3-N, protozoal counts, and the protease activity in rumen fluid were all linearly declined, but fungal counts increased linearly. No significant changes were found in pH, activities of xylanase and amylase of rumen fluid. The PCR copies of Fibrobacter succinogenes,Ruminococcus albus, Butyrivibrio fibrisolven and Selenomonas ruminantium increased to maximum of 21.4%, 22.7%, 22.6% and 20.6%(all above P<0.05), whereas these of Prevotella bryantii, Clostridium aminophilum, methanogens and microscopic counting of great coli decreased to maximum of 24.5%, 34.8%, 21.2% and 52.2%(all above P<0.05);but Salmonella bovis and Prevotella ruminicola were not affected by PAM. [Conclusion]PAM supplementation at 2.0 g/kg diet can reduce protozoa but increase bacteria, particularly those species for fibre digestion, and fungi in rumen.The effect of PAM on bacterial species was selective. These changes finally enhanced activities of enzymes for fibre digestion in rumen, and stimu-lated VFI of sheep, suggesting a potential application of PAM in ruminant production.
