【作者】 段铭；

【导师】 高宏伟；

【作者基本信息】 中国人民解放军军需大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 本试验从脂肪源和吡啶羧酸铬这两个角度研究其对肉仔鸡脂肪代谢的影响。取216只1日龄艾维茵肉仔鸡，分成6组(每组36只，组内设三个重复，每个重复12只)，以2×3的方式在基础日粮中分别添加牛油、豆油和鱼油，及空白和1mg／kg的吡啶羧酸铬。试验开始后分别在15、29、43、54日龄称重、屠宰、采血，在29日龄另取肝脏，计算ADG、F／G、PDAF、L／B，检测血清中TP、GLU、BUN、TG、CH、VLDL、LDL和HDL。12～15d进行消化代谢试验。运用RT-PCR检测肝脏样品内FAS、ACC和HMG-CoA还原酶基因在mRNA水平上的表达水平。通过上述试验得出如下结果：(1)鱼油的表观利用率明显高于其它两种脂肪，而铬有改善饲料中蛋白质表观利用率的趋势；(2)脂肪源并不影响肉仔鸡的生长，但是对腹脂沉积有一定的影响，对于肝脏重量鱼油有着特殊的影响，使肝脏重量明显增加。铬有降低腹脂沉积的趋势；(3)与牛油和豆油相比较，鱼油降低了血清中甘油三酯、胆固醇，降低了HDL的浓度，只是对指标影响的显著程度不一致。铬降低了血清中BUN、GLU、TG，升高了TP和HDL的浓度，但是对各指标影响的差异程度也不一致；(4)脂肪源可以影响胴体的组分，尤其是鱼油可以降低胸肌和腿肌内胆固醇的含量。铬可以升高其内蛋白质的含量，降低甘油三酯和胆固醇的含量；(5)鱼油对FAS、ACC、和HMG-COA还原酶基因表达的抑制作用最为明显，三种基因的mRNA的量分别比牛油组下降了50.35％、40.35％、81.49％，而豆油抑制表达的效果不如鱼油，鱼油中富含的长链PUFA的作用更大；(6)以豆油组来分析添加吡啶羧酸铬和未添加对三个酶基因表达的影响，发现添加铬后FAS和HMG-CoA还原酶的转录明显受到影响，分别比对照组下降34.82％和48.26％，而ACC受影响很小，其转录只下降了3.87％。结果表明：脂肪源中的PUFA在影响肉仔鸡脂肪代谢中具有独特的作用，有别于其它类型的脂肪酸；铬的添加可以影响到肉仔鸡的蛋白质和脂肪代谢，但是起作用的条件复杂。更多还原

【Abstract】 The objective of the research was to evaluate the effects of dietary supplementation with fat sources and chromium picolinate on the lipid metabolism of broiler chickens.216 1-day-old broilers were assigned at random to 6 groups with 3 replicates.2(0 and Img/kg chromium picolinate) X 3(beef tallow,soybean oil and fish oil)treatment were used.The broiler were raised for 8 weeks.The apparent availability of dietary nutrients in broiler chicks were obtained during 15-17 days old,and component of muscle were assayed.The ADG, F/G, PDAF, L/B, and TP, GLU, BUN, TG, TC, VLDL.LDL, HDL in serum were detected at interval Hdays.Two chickens of each groups were killed quickly in 29d,and got a piece of liver.RT-PCR was applied to dectect gene expression of FAS.ACC, HMG-CoA reductase.The results were as follows: (1) The apparent availability of fish oil was higher than soybean oil and beef tallow (P<0.05), and there was a tendency of increasing the apparent availability of crude protein (CP) by chromium; (2) Addition of the different fat sources influenced abdominal fat deposition slightly,and fish oil increased weight of liver significantly (P<0.05). Dietary chromium supplement improved growth,increased F/G and decreased abdominal fat content, but difference was not significant(P>0.05); (3) Fish oil in dietary decreased serum TG, TC, and HDL concentration, but difference level was not coincidence. Supplement of chromium decreased BUN, GLU and TG, on the contrary, TP and HDL concentration were risen, similarly, there was not the sameness of effect degree; (4) Fish oil especially decreased the content of cholesterol. The content of protein in carcass was improved by chromium, and triglyceride and cholesterol decreased; (5) Dietary fish oil reduced by 50.35%,40.35%, 81.49% the hepatic abundance of FAS, ACC, HMG-CoA reductase, compared with beef tallow. Fish oil ,rich in polyunsaturated fatty acid, was more effective than soybean oil; (6) Effects of 1mg/kg chromium picoiinate on abundance of FAS and HMG-CoA reductase mRNAs is obvious, reduced by34.82% and 48.26%, compared with no chromium picoiinate group. However the change of abundance of ACC mRNAs reduced by only 3.87%.更多还原