The Effects Of AHL-lactonase And Artemisia Seed Polysaccharide On Rumen Microflora And Nutrient Metabolism And Immune Effect In Sheep

In this thesis a comprehensive research was carryed out to study the effects of AHL-lactonase(AHLL) and Artemisia Seed Polysaccharide (ASP) on Rumen Microbiology,rumen microflora and Nutrient Metabolism and Immune Effect in Sheep.Nine healthy and fitted with rumen fistula Ordos fine wool sheep, according to the weight divided into three groups.The NFC/NDF diets A was 0.48, B was 0.76, C was 1.53. First, the in vitro evaluation of the suitable amount of additive was carried out,then we had three animal studies,the first phase for the control period,in the second phase add the basal diet with AHLL,in the third period the basic diet with ASP. The results obtained showed that:1. An in vitro study was conducted using a 3 X 4 factorial design with three diets NFC:NDF levels, and AHLL levels of 0,0.1,0.3 and 0.5%, and ASP levels of 0.0,0.5,1.0 and 1.5%. With the evaluation the Gas production of 24 hour, pH, VFA and NH3-N concentrations, the suitable amount of AHLL is 0.3%,1.0% ASP for diet A and C,0.5% for B.2. Rumen contents sampled at 2 h intervals for 12 h afterfeeding,with the effects of t-AHLL and ASP on rumen fermentation in vivo, ASP decreased production of acetate,propionate,butyrate,total VFA and molar proportion of acetate to propionate, AHLL decreased production of acetate, total VFA and molar proportion of acetate to propionate. Added ASP increased concentrations of ammonia-N.3. Next-generation sequencing technology was used to test the bacterial community of the rumen., The bacteria shannon index and simpson index decreased when supplemented AHLL and ASP in diet B. The amouts of typical OUT with ASP＞control＞AHLL. The relative richness of the bacteria genus was identified, Firmicutes and Bacteroides is the dominant populations for the rumen flora. With the Metastats analysis we found that, with the adding of AHLL, an increase of relative occurrence of Synergistetes of diet A, but reducing the proportion of Tenericutes for diet B. The percentage of fibrobacteresincreased for diet B with the adding of ASP. By comparing the species richness we found that the Campylobacter, Porphyromonadaceae were decreased by adding AHLL,and Desulfovibrionaceae, Vibrio, Campylobacter jejuni were disappeared by adding ASP.4. The metabolism studies were conducted to observe the effects of ASP and AHLL.The data indicated that the addition of AHLL and ASP resulted in higher DM apparent digestibility, the NDF apparent digestibility and dietary nitrogen metabolic rate increased by adding ASP, but the emission of fecal N for diet B decreased.5. The objective of this study was to determine the antioxidant capacity and immune effect of AHLL and ASP in vivo. The serum total antioxidant capacity (T-AOC), catalase (CAT) activity were improved and malondialdehyde (MDA) content decreased by adding AHLL and ASP, total superoxide dismutase(T-SOD) capacity increased by adding ASP. The serum total protein content were improved by adding AHLL and ASP, and the serum IgA content was improved by adding ASP.6. The number of E. coli were reduced in sheep manure by adding AHLL, the Staphylococcus content were reduced by adding AHLL and ASP.