复合植物精油提高肉仔鸡生长性能和抗病力的初步研究与应用

发布时间：2018-08-29 14:20

【摘要】：长期以来,抗生素作为抗病促生长用药广泛在畜禽日粮中低剂量长期添加,养殖现场预防用药则更加普遍。但近年来,由于耐药性风险和公众安全意识的提高,寻找安全、有效的新型制剂加以应用是当前的首要目标。植物精油来源于天然植物,具有挥发性和特殊气味,有多种药理活性,在医药保健领域已有应用,在畜牧业应用才逐渐兴起。本研究选用百里香酚、丁香酚、香芹酚、柠檬烯、柠檬醛、肉桂醛、大蒜素7种精油单体为研究对象,采用正交设计、析因设计进行最佳抗菌方剂筛选;通过动物饲养试验对肉仔鸡生长性能和屠宰性能进行评估,并测定血清生化指标白蛋白等,以确定适宜添加量;采用MTT法、ELISA法、免疫器官指数测定等研究复合植物精油对肉鸡免疫功能的影响;建立大肠杆菌O78攻毒肉鸡模型,采用微生物培养法、微量凝集法、ELISA法、荧光定量PCR法及制备肉鸡心、肝、脾、肾组织病理切片等,研究其对肉用鸡抗病力的影响及其免疫学机制,为生产实践提供参考依据,并进行现场饲养试验,确定其经济实用性。结果显示:筛选确定精油单体丁香酚、百里香酚、香芹酚为方剂组分,组成方剂为丁香酚3mg、百里香酚3mg、香芹酚2mg。对大肠杆菌MIC为625μg/m L,金黄色葡萄球菌为39μg/m L,沙门菌为19.5μg/m L,对大肠杆菌MBC为1250μg/m L,金黄色葡萄球菌为78μg/m L,沙门菌为39μg/m L;在42天的肉仔鸡饲养试验中,剂量为80mg/kg和160mg/kg的试验组肉鸡平均日增重显著高于对照组(P0.01),但料肉比显示80mg/kg组显著低于对照组(P0.05),160mg/kg组则采食量和料肉比均显著高于对照组(P0.05);同时胸肌率和腿肌率得到了提高(P0.05);血清总蛋白、白蛋白、尿素氮、甘油三酯、总胆固醇含量差异均不显著(P0.05),但血清尿素氮、甘油三酯、总胆固醇含量有趋于降低的趋势;复合植物精油可以使外周血白细胞和红细胞含量增加,显著促进淋巴细胞增殖、增加血清中补体含量、提高新城疫抗体滴度和溶菌酶的水平(P0.05),促进免疫球蛋白和细胞因子IL-2、TNF-α、IFN-γ的分泌(P0.01),肉仔鸡血清超氧化歧化酶活性和总抗氧化能力显著增加(P0.05),并可极显著提高部分免疫器官指数(P0.01);在大肠杆菌攻毒肉鸡试验中,添加植物精油降低了肉仔鸡死亡率(P0.05),有效减缓体增重降低和料肉比升高,同时,相对于未添加精油攻毒组极显著降低器官载菌量(P0.01),内脏器官病变程度减轻,大肠杆菌攻毒后肉鸡血清中IL-6和s TLR4的含量极显著增加(P0.01),脾脏TLR4和NF-κB的m RNA表达量极显著提高(P0.01);但添加精油较饲喂基础日粮的攻毒肉鸡血清中IL-6和s TLR4含量显著降低(P0.05),脾脏TLR4和NF-κB的m RNA表达量极显著降低(P0.01);养殖应用证明,该复合植物精油可以节约饲料5%,降低死淘率,每只鸡提高经济收益0.9元。结论如下:本复合植物精油方剂为丁香酚3mg、百里香酚3mg、香芹酚2mg,对大肠杆菌、沙门菌、金黄色葡萄球菌都有一定的抑杀作用;适宜添加量为80mg/kg饲料;可以增加肉鸡的免疫功能;提高其对病原微生物的抗感染水平;而抗炎过程,可能与精油抑制TLR4/NF-κB通路进而抑制炎性细胞因子分泌等免疫应答有关;应用试验表明经济实用。综上所述,本研究筛选所得复合植物精油可以提高肉仔鸡生长性能和抗病力,具有进一步研究和应用价值。
[Abstract]:For a long time, antibiotics have been widely used in livestock and poultry diets as disease-resistant and growth-promoting drugs at low doses for a long time, and preventive drug use in farming sites has become more common. Plant, with volatile and special smell, has a variety of pharmacological activities, in the field of medical and health care has been applied in the application of animal husbandry before gradually rising. This study selected thymol, eugenol, carvacrol, limonene, citral, cinnamaldehyde, allicin seven essential oil monomers as the research object, using orthogonal design, factorial design for the best antimicrobial prescription. The effects of compound vegetable essential oils on the immune function of broilers were studied by MTT, ELISA and immune organ index. The broiler model was established by E. coli O78. Microbial culture, microagglutination, ELISA, fluorescence quantitative PCR and pathological sections of heart, liver, spleen and kidney of broiler chickens were used to study their effects on disease resistance of broiler chickens and their immunological mechanism. The results showed that screening and determining essential oil monomer was economical and practical. Eugenol, thymol and carvacrol were the components of the prescription. The prescription was composed of 3 mg eugenol, 3 mg thymol and 2 mg carvacrol. The MIC of E. coli was 625 ug/ml, Staphylococcus aureus was 39 ug/ml, Salmonella was 19.5 ug/ml, E. coli MBC was 1250 ug/ml, Staphylococcus aureus was 78 ug/ml and Salmonella was 39 ug/ml. In broiler feeding experiment, the average daily gain of broilers in the 80 mg/kg and 160 mg/kg dosage groups was significantly higher than that in the control group (P 0.01), but the feed-to-meat ratio showed that the 80 mg/kg group was significantly lower than that in the control group (P 0.05), while the feed intake and feed-to-meat ratio in the 160 mg/kg group were significantly higher than that in the control group (P 0.05); the chest muscle rate and leg muscle rate were also increased (P 0.05). The contents of protein, albumin, urea nitrogen, triglyceride and total cholesterol were not significantly different (P Antibody titer and lysozyme level (P 0.05), promote the secretion of immunoglobulin and cytokines IL-2, TNF-a, IFN-gamma (P 0.01), Broiler Serum Superoxide Dismutase Activity and total antioxidant capacity significantly increased (P 0.05), and can significantly improve the index of some immune organs (P 0.01); in the E. Essential oils decreased mortality (P 0.05), effectively slowed down body weight gain and increased feed-to-meat ratio. Meanwhile, compared with the non-essential oils treated group, the bacterial load of organs was significantly reduced (P 0.01), the degree of visceral organ lesion was alleviated. The levels of IL-6 and s TLR4 in serum, TLR4 and NF-kappa B in spleen were significantly increased (P 0.01). The expression of M RNA in serum was significantly increased (P 0.01), but the contents of IL-6 and s TLR4 in serum were significantly decreased (P 0.05) and the expressions of TLR4 and NF-kappa B in spleen were significantly decreased (P 0.01) compared with those in broilers fed with basal diet. The conclusion is as follows: Eugenol 3 mg, thymol 3 mg, carvacrol 2 mg have certain inhibitory and killing effects on Escherichia coli, Salmonella and Staphylococcus aureus; the appropriate dosage of 80 mg/kg feed; can increase the immune function of broilers; improve its anti-infective level to pathogenic microorganisms; and anti-inflammatory process, Essential oils may be related to the inhibition of TLR4/NF-kappa B pathway and the subsequent inhibition of inflammatory cytokine secretion and other immune responses; application experiments show that it is economical and practical.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S831.5

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