中药添加剂对高温条件下肉牛肌内脂肪沉积和脂肪代谢的影响

发布时间：2018-04-24 23:34

本文选题：中药添加剂 + 肉牛　；参考：《江西农业大学》2017年硕士论文

【摘要】：中药具有抗应激、抗氧化、调节免疫及脂类代谢等作用。前期研究表明,在饲料中添加中药可缓解肉牛热应激反应,改善高温条件下肉牛的生长性能。本研究旨在研究中药添加剂对高温条件下肉牛宰后肌肉品质的影响及机制。主要包括以下三部分。试验一:研究添加不同中药复方对肉牛的抗热应激作用。本试验选取18头健康、初重为435.30±16.26kg的22月龄育肥期锦江黄牛未去势公牛,随机分为对照组、清热组和健脾组3组,每组6头牛。其中对照组饲喂基础饲粮,两个中药组分别在精料中添加了1%的健脾化湿方(健脾组)和2%的清热祛湿方(清热组)。试验牛饲养于夏季高温高湿条件下,试验为期60 d。结果表明:试验期牛舍温湿指数大于72,肉牛处于热应激状态。与对照组比较,两中药组试验牛的体温与呼吸频率在20d和40d均显著降低(P0.05)。此外,与对照组相比,健脾组的血清总蛋白、白蛋白、球蛋白、甘油三酯、胰岛素和脂联素含量升高(P0.05),但总胆固醇含量降低(P0.05);清热组的血清生长激素、甲状腺激素(T3和T4)均显著升高,胰岛素水平降低(P0.05)。两个中药组血清抗氧化酶活性均显著高于对照组(P0.05),丙二醛含量则显著下降(P0.05)。这表明,饲粮中添加健脾方和清热方均可缓解肉牛的热应激反应,其中清热方在改善生产性能方面的效果较好。试验二:选择清热组开展屠宰试验,研究清热方对热应激肉牛肌肉品质及肌内脂肪沉积的影响。结果显示:与对照组相比,清热组肉牛宰后眼肌面积、嫩度等均有改善的趋势(P0.05),肌肉24小时后pH值显著降低(P0.05)。清热组的单不饱和脂肪酸(C14:1、C16:1、C17:1和C18:1)比对照组均有升高的趋势(P0.05)。此外,通过冰冻切片脂肪染色,在光镜视野下观察到清热组肌束之间的橘红色脂肪滴显著多于对照组,这些结果表明添加清热方可促进高温条件下肉牛肌内脂肪的沉积,对牛肉的风味有一定的改善效果。试验三:为进一步探讨清热方对高温条件下肉牛肌内脂肪沉积的调控机制,本研究测定了肉牛脂肪代谢酶的活性及相关因子基因表达量的变化。结果显示:与对照组相比,清热组肉牛皮下脂肪中乙酰辅酶A羧化酶(ACC)、脂肪合成酶(FAS)和激素敏感性脂肪酶(HSL)的活性显著降低,脂肪组织和肝脏中的过氧化物酶体增殖物激活受体γ辅激活因子1(PGC-1α)、腺苷酸激活蛋白激酶α1(AMPKα1)、过氧化物酶体增殖物激活受体γ(PPARγ)和脂蛋白脂酶(LPL)的相对基因表达量均显著升高(P0.05)。结果表明,饲粮中添加中药复方可上调热应激期肉牛脂肪代谢调控因子的基因表达,改善脂肪沉积。综上结果:饲料中添加中药复方可以缓解肉牛的热应激反应。其中,清热方可促进高温条件下肉牛的肌内脂肪沉积,改善牛肉的风味,上调肉牛脂肪代谢调控因子的基因表达量。
[Abstract]:Chinese medicine has anti-stress, anti-oxidation, immune regulation and lipid metabolism and so on. The previous studies showed that adding Chinese medicine to the feed could alleviate the heat stress reaction of beef cattle and improve the growth performance of beef cattle under high temperature. The purpose of this study was to study the effect and mechanism of Chinese medicine additive on muscle quality of beef cattle after slaughter under high temperature. Mainly includes the following three parts. Experiment 1: the anti-heat stress effect of different Chinese herbal compound on beef cattle was studied. In this experiment, 18 healthy and 435.30 卤16.26kg uncastrated cattle were randomly divided into three groups: control group, heat clearing group and spleen invigorating group, with 6 cows in each group. The control group was fed with basic diet, and the two groups were supplemented with 1% invigorating spleen and removing dampness (invigorating spleen group) and 2% clearing heat and dispelling dampness prescription (heat clearing group) respectively. The test cattle were fed under high temperature and high humidity in summer for 60 days. The results showed that the temperature and humidity index of cattle was more than 72, and the beef cattle were in heat stress state. Compared with the control group, the body temperature and respiratory rate of the two groups were significantly lower than those of the control group at 20 d and 40 d, respectively. In addition, compared with the control group, serum total protein, albumin, globulin, triglyceride, insulin and adiponectin contents in the spleen invigorating group increased P0.05N, but the total cholesterol content decreased P0.05G, and the serum growth hormone in the heat-clearing group. Thyroid hormone T 3 and T 4) increased significantly, and insulin level decreased P 0.05. The activities of serum antioxidant enzymes in the two groups were significantly higher than those in the control group (P 0.05), while the content of malondialdehyde (MDA) decreased significantly (P 0.05). The results showed that the addition of Jianpi recipe and Qingre recipe in the diet could alleviate the heat stress reaction of beef cattle, and the effect of Qingre recipe on improving the production performance was better. Experiment 2: the effect of Qingre recipe on muscle quality and intramuscular fat deposition of heat stressed beef cattle was studied. The results showed that, compared with the control group, the area and tenderness of the eye muscle in the heat-clearing group showed a trend of improvement (P 0.05), and the pH value of the muscle decreased significantly (P 0.05) after 24 hours. Compared with the control group, the monounsaturated fatty acids C14: 1: 1, C16: 1, C17: 1 and C18: 1 in the heat-clearing group showed an increasing trend. In addition, the orange fat droplets between muscle bundles in Qingre group were significantly higher than those in control group under light microscope. These results indicated that Qingre decoction could promote the deposition of intramuscular fat in beef cattle under high temperature. It can improve the flavor of beef. Experiment 3: in order to further study the regulation mechanism of Qingre recipe on fat deposition in muscle of beef cattle under high temperature, the activity of fat metabolizing enzyme and the expression of related factor gene were measured. The results showed that the activities of acetyl coA carboxylase (ACCA), adipose synthase (FAS) and hormone sensitive lipase (HSL) in hypodermic fat of cattle in heat-clearing group were significantly lower than those in control group. The relative gene expression of peroxisome proliferator-activated receptor 纬 -coactivator 1(PGC-1 伪, adenylate activated protein kinase 伪 1(AMPK 伪 1, peroxisome proliferator activated receptor 纬 -PPAR- 纬 and lipoprotein lipase (LPL) in adipose tissue and liver were significantly increased. The results showed that the gene expression of fat metabolism regulatory factors in beef cattle during heat stress was upregulated and fat deposition was improved by adding traditional Chinese medicine compound in diet. The above results showed that the addition of traditional Chinese medicine compound in feed could alleviate the heat stress reaction of beef cattle. Qingre decoction promoted intramuscular fat deposition, improved beef flavor and up-regulated gene expression of fat metabolism regulatory factors in beef cattle under high temperature.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S823.5

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