Effects Of Yeast Culture On Performance ,Nutrient Digestibility And Rumen Development In Shanbei Cashmere Goat Lambs

The experiment was conducted to study the effects of yeast culture(YC) supplied in different concentrate-roughage (C/R) ratio diets on performance ,nutrient digestibility and rumen development in Shanbei cashmere goat lambs. Sixteen lambs were allotted randomly into four groups using 2×2 factorial arrangement with different concentration diets and YC levels as main effects. Lambs in groupⅠwere fed a basal diet with C/R ratio of 3:7 added 20 g YC /kg DM, and lambs in groupⅡwere fed the same diet as groupⅠ, except YC. Animals in groupⅢwere fed a basal diet with C/R ratio of 5:5 added 20 g YC /kg DM , and in groupⅣwere fed the same diet as groupⅢexcept YC.Experiment 1: A 50d feeding experiment was conducted to study the effects of YC on performance and blood parameters of lambs. The lambs were weighted every 10 days and diet intake was noted everyday. At the end of this experiment, blood samples were collected. The results were as follows: Weight gain and daily gain in groupⅠwas significantly greater (P<0.05) than that of groupⅡ.The DMI in groupⅢwas significantly greater (P<0.05) than that of groupⅣ, and groupⅠalso greater than groupⅡ(P=0.077). There were no differences observed for feed efficiency in all the groups (P>0.05) while the lowest feed efficiency was found in groupⅠ(7.72). Blood parameters were not found differences (P>0.05) in this 4 groups, the same as plasma IGF-I at different sampling time (after intaking 0,2,4,6 and 8h).Experiment 2: The goal of this test was to study the nutrient digestibility when YC was added in two different concentrate-roughage (C/R) ratio diets. The data suggest that the apparent digestibility of CP and NDF in groupⅠwas significantly greater (P<0.05) than that of groupⅡ, but not observed between groupⅢand groupⅣ. No significant differences (P>0.05) were observed for the apparent digestibility of DM, OR, EE and ADF among 4 groups. And the digestibility of CP and NDF was effected by interaction between C/R and supplied YC significantly (P<0.05), but the others were not effected. Nitrogen deposition of groupⅠw as greater than groupⅡ(P<0.05), and groupⅢwas greater than groupⅣ(P<0.05) too. Dung nitrogen discharge of groupⅠwas lower than groupⅡ, but no significant different (5.06 g/ (d·lamb) vs. 5.43 g/ (d·lamb)).Experiment 3: At the end of experiment 2 all the lambs were slaughtered, and rumen tissues were sampled for rumen epithelial growth measurements. Make the rumen epithelial tissue into paraffin section to measure the papillae length, papillae width and rumen wall thickness. The results were as follows: the reticulum weight of groupⅠwas greater than groupⅡ(P<0.05), and the other parts of stomachs compositions were not effected by YC. Carboxymethylcellulose activity of groupⅠwas greater than groupⅡ, and groupⅢwas greater than groupⅣ(P<0.05). Pectase, Xylanses and Filter paper enzyme activity were not observed differently (P>0.05) around 4 groups. The papillae length and papillae width in groupⅢwas significantly greater (P<0.01) compared with groupⅣ.The C/R ratio and interaction between C/R and supplied YC also significantly effected papillae width (P<0.01).For the colour of rumen tissues, groupⅠand groupⅡ's appeared darker than groupⅢand groupⅣ's. And rumen papillae in paraffin section, there was some branched papillae of groupⅡ, and that of groupⅣlooked slender. The papillae of groupⅠand groupⅢwas more healthy, looked like a tongue.In sum, lambs'performance was improved when YC was added in diet of 3:7 concentrate-roughage ratio.Then YC can improve the apparent digestibility of CP and NDF in diet of 3:7 concentrate-roughage ratio. Last, YC was good for rumen papillae development, especially in diet of 5:5 concentrate-roughage ratio YC shows a effective role for keeping normal rumen papillae form.