酵母培养物对绒山羊机体免疫指标的影响(英文)

Effects of Yeast Culture on Immune Indices of Cashmere Goats

本研究旨在观察酵母培养物(yeast culture,YC)对绒山羊机体免疫指标的影响。选用12只健康的内蒙古白绒山羊半同胞羯羊,按体重配对原则分为4组。其中A1、A3处理组饲喂精粗比为3∶7的基础日粮,B1、B2处理组饲喂精粗比为2∶8的基础日粮。采用自身对照试验方法,对照期饲喂基础日粮,试验期在基础日粮上分别添加不同水平的酵母培养物。各处理组日粮中YC添加量分别为A1:2.0%、A3:3.0%、B1:2.0%和B2:2.5%。分别在对照期最后1天、添加YC的第15天、第45天测定绒山羊机体免疫指标。结果表明:对照期、添加YC后的第15天和第45天,各处理组间血液IgA、IgG、T淋巴细胞亚群CD4+、CD8+比例以及CD4+/CD8+的比值间均无显著差异(P>0.05)。添加YC后的第15天和第45天,A3和B1处理组血清IgA含量极显著高于对照期(P<0.01),B2处理组血清IgG含量显著高于对照期(P<0.05)。各处理组T淋巴细胞亚群中CD4+的比例在添加YC后第15天略有升高(P>0.05);CD8+的比例在试验期第15天略有下降(P>0.05);CD4+/CD8+的比值在添加YC第15天均有较大幅度提高(P>0.05)。添加YC后第45天3个指标均恢复到对照期水平。结果表明,添加YC可以显著增加绒山羊血清IgA含量,并提高血清IgG含量;在添加YC初期机体外周血CD4+/CD8+比例有升高的趋势.

This experiment was conducted to study the effect of yeast culture （YC） on immune indices in cashmere goats. Twelve mature half-sib wethers of Inner Mongolia white cashmere goats were divided into four groups according to the weight in a 45-d self-controlled trial. The goats in A1 and A3 groups were fed with a basal diet with concentrate to roughage （C/R） ratio of 3 ： 7; and the animals in B1 and B2 groups were fed with another basal diet with a C/R ratio of 2 ： 8 in control period. After 14 days of control period, yeast culture （YC） was added at a level of 2.0% in A1 and B1 groups, 3.0% in A3 and 2.5% in B2 group respectively in YC supplemented period. Blood samples used to determine the immune indices were taken from the jugular vein on the last day of control period, the 15^th day and the 45^th day of YC supplemented period. The results showed that there was no significant difference in proportions of serum IgA, IgG, CD4^＋ and CD8^＋ , and the ratio of CD4^＋ to CD8^＋ among groups in each period （P 〉 0.05）. Compared with the control period, supplementing YC in diets significantly increased the concentrations of serum IgA in A3 and B1 groups （P〈0.01）, and the concentration of IgG in B2 group （P〈0.05）. On the 15^th day of YC supplementation period, the percentage of T-lymphocyte subpopulation CD4^＋ increased slightly （P〉0.05）, while the percentage of CD8^＋ decreased slightly （P〉0.05）, which resulted in the CD4^＋/CD8^＋ ratio being enhanced （P〉0.05）; and the three indexes of T-lymphocyte subpopulation went back to the levels of control period on the 45^th day of YC supplementation period （P〉0.05）. These results indicated that YC supplement in diets could increase the serum IgA concentration of cashmere goats significantly （P〈0. 05）, and tended to increase the serum IgG concentration. There was a trend of increasing the CD4^＋ / CD8^＋ ratio in peripheral blood lymphocytes in initial stage of YC supplementation.