【作者】 魏涛；

【导师】 高玉鹏；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 本研究探讨了日粮中添加复合酶制剂对产蛋高峰期后的蛋鸡经济性状影响的机制,分析了蛋鸡生产性能的变化与其抗氧化功能、免疫功能、消化道环境及微生物区系变化的关系。试验选择540只37周龄健康、体重相近、产蛋性能基本一致的海兰褐壳蛋鸡随机分为4个处理组:(A)基础日粮(对照组);(B)基础日粮+0.1 %复合酶制剂;(C)基础日粮+0.2 %复合酶制剂;(D)基础日粮+0.3 %复合酶制剂。试验期56 d。试验结果表明:1、复合酶制剂对产蛋高峰后的蛋鸡生产性能的影响日粮添加不同水平的复合酶制剂对产蛋高峰后期蛋鸡的产蛋率、蛋重、蛋形指数、蛋黄重量、蛋壳厚度、哈氏单位等均没有显著影响(P>0.05);日粮添加复合酶制剂对蛋鸡料蛋比的影响效果不显著(P>0.05)。2、复合酶制剂对产蛋高峰后蛋鸡肠道形态学的影响日粮添加不同复合酶水平对蛋鸡肠道绒毛高度的影响不显著(P>0.05)。复合酶制剂提高了肠道V/C值(P<0.05),使隐窝深度变浅(P>0.05),随复合酶水平增大V/C增加及隐窝变浅的趋势。复合酶也有降低肠壁厚度的趋势,但存在剂量问题,过高的复合酶水平可能会使肠壁厚度增加。3、复合酶制剂对产蛋高峰后蛋鸡肠道相对重量的影响日粮复合酶水平对蛋鸡消化道相对重量影响不显著(P>0.05);41周龄时,复合酶可显著降低蛋鸡空肠相对长度(P < 0.05),0.3 %的添加水平降低的幅度最大;45周龄时,复合酶可显著提高空肠相对长度(P < 0.05)。4、复合酶制剂对产蛋高峰后蛋鸡肠道内容物pH的影响复合酶对蛋鸡肌胃、十二指肠、空肠、回肠和盲肠的pH值影响不显著(P > 0.05),但有提高肌胃、盲肠pH和降低十二指肠、空肠和回肠pH的趋势。5、复合酶制剂对产蛋高峰后蛋鸡肠道总蛋白酶活力的影响复合酶显著提高蛋鸡肌胃、十二指肠、空肠和回肠的总蛋白酶活性(P< 0.05)。其中0.3 %的复合酶制剂添加水平的复合酶与对照组相比,显著提高了蛋鸡肌胃、十二指肠、空肠和回肠的总蛋白酶活性(P < 0.05)。6、复合酶制剂对产蛋高峰后蛋鸡肠道内容物和粪便微生物区系的影响添加复合酶制剂可以减少盲肠和粪便中大肠杆菌数,提高盲肠和粪便中乳酸杆菌菌群的数量。41周龄时,0.3%的添加水平可以显著减少盲肠内容物中大肠菌群的数量,且差异显著(P< 0.05),0.2%的添加水平可以显著减少粪便中大肠菌群的数量,且差异显著(P< 0.05)。45周龄时,0.2 %,0.3 %的添加水平可以显著提高粪便中乳酸菌菌落的数量,且差异显著(P< 0.05)。7、复合酶制剂对产蛋高峰后蛋鸡血清抗氧化酶活力及主要代谢激素水平的影响日粮复合酶具有降低蛋鸡血清中谷胱甘肽过氧化物酶(GSH-px)含量和提高超氧化物歧化酶(SOD)的趋势。41周龄时,显著提高总抗氧化能力(T-AOC)水平(P< 0.05);45周龄蛋鸡血清GSH-px、SOD、T-AOC含量影响差异不显著(P > 0.05)对血清中GH、T3和T4影响差异不显著(P > 0.05)。8、复合酶制剂对产蛋高峰后蛋鸡免疫指标的影响41周龄时, 0.2 %和0.3 %的复合酶制剂添加水平与对照组相比,提高了新城疫(ND)抗体滴度,差异显著(P < 0.05);0.1 %和0.3 %的添加水平和对照组相比,提高了禽流感(H9)抗体滴度,差异显著(P < 0.05)。45周龄时,0.2 %和0.3 %的添加水平和对照组相比,提高了新城疫抗体滴度,差异显著(P<0.05);提高了禽流感(H9)抗体滴度,但差异不显著(P>0.05)。结论:试验表明:对产蛋高峰期过后的蛋鸡,在营养总体平衡的常规日粮中,再添加复合酶制剂饲喂,其经济性状的改良效应不明显。主要原因在于:此期产蛋鸡的经济性状的变化受日粮因素影响的敏感性较产蛋高峰期有明显的下降,其代偿性较强;日粮中添加复合酶制剂不会明显改善此期蛋鸡消化道环境和形态,抗氧化能力和主要代谢激素水平。即便提高了蛋鸡肠道蛋白酶活性、免疫功能,降低了有害菌群数量,但这些效应对健康蛋鸡而言,均未达到改善其生产性能的效果。故在生产实践中,对饲喂营养平衡的常规日粮的产蛋高峰过后蛋鸡,添加复合酶制剂的必要性值得商榷。更多还原

【Abstract】 This study investigated the effects and mechanism of different dietary enzyme levels after laying peak, analysis of the performance of laying hens changes in antioxidant function, immune function, gastrointestinal environment and microbial flora change. 540 healthy 37 weeks Highland brown egg layer were randomly allocated into 4 treatment groups: (A) basal diet (control group); (B) basal diet + 0.1% enzyme preparation; (C ) basal diet + 0.2% enzyme preparation; (D) basal diet supplemented with 0.3% enzyme preparation. A period of 56 d in the feeding trial.The results showed that:1. complex enzyme in peak egg production performance of laying hensDifferent levels of dietary enzyme complex on the late peak laying rate, had no significant effect of egg weight(P> 0.05); had no significant effect on the egg shape index, yolk weight, egg shell thickness, Hastelloy Unit (P> 0.05); complex enzyme was not significant(P> 0.05) on the egg ration.2.enzyme preparation on the the intestinal morphology after laying peak of hensAdding different levels of dietary enzyme was not significant on the intestinal villi height of laying hens (P> 0.05). Improved the intestinal enzyme complex V / C value (P <0.05), crypt depth shallower (P> 0.05), with the enzyme level increased V / C increase and the trend of recess. Enzyme also had the trend of reducing the wall thickness, high enzyme levels may cause bowel wall thickness.3.enzyme preparation on the relative weight of intestine of hens afer laying peakDietary enzyme had no significant difference (P>0.05) for 41 and 45 weeks hen,s relative weight of digestive tract layers; 41 weeks, significantly reduced the relative length of the jejunum (P <0.05), 0.3 % of the added level reduced maximum amplitude; 45 weeks, the enzyme can significantly improve the relative length of the jejunum (P <0.05).4. enzyme preparation on the pH of intestinal contents of laying hens after laying peak41 weeks,there were no significant difference on muscular stomach, duodenum, jejunum, ileum and cecum pH (P > 0.05), 41 weeks, increased muscular stomach, cecum pH, lower duodenum, jejunum and ileum pH. 45 weeks , there were no significant difference on muscular stomach, duodenum, jejunum, ileum and cecum pH (P > 0.05), increased muscular stomach, ileum, and cecum pH. 5.enzyme preparation on the total protease activity of intestinal of laying hens after laying peakEnzyme increased 41,45 weeks laying hens muscular stomach, duodenum, jejunum and ileum of the total protease activity (P <0.05). 0.3% enzyme levels compared with the control group, significantly increased 41,45 weeks laying hens muscular stomach, duodenum, jejunum and ileum of the total protease activity (P <0.05).6.enzyme preparation on the microflora of intestinal contents and faecal of laying hens after laying peakEnzyme preparations can reduce the number of Escherichia coli in the cecum and feces, increased cecal and fecal flora in the number of lactic acid bacteria. 41 weeks, 0.3% level can significantly reduce the number of coliform bacteria in the cecal content, significant differences (P <0.05).0.2 % of the added level can significantly reduce the amount of fecal coliform, and difference significantly (P <0.05). 47 weeks of age, 0.2 %, 0.3 % of the added level can significantly increase the number of colonies of lactic acid bacteria in feces, and the difference is significant (P <0.05).7. enzyme preparation on the serum antioxidant enzymes and major metabolic hormone levels of laying hens after laying peakThe level of dietary enzyme layers with lower serum glutathione peroxidase (GSH-px) content and increased superoxide dismutase (SOD) trend. 41 weeks, significantly increased total antioxidant capacity (T-AOC) levels (P <0.05); had no significant difference layers of serum GSH-px, SOD, T-AOC ( P > 0.05) of serum .GH, T3 and T4 were not significantly affected (P> 0.05).8. enzyme preparation on the immune parameters of laying hens after laying peak41 weeks, 0.2% and 0.3% of the added levels increased Newcastle disease (ND) antibody titers, the difference was significant (P <0.05); 0.1% and 0.3% adding level increased avian influenza (H9) antibody titers, the difference was significant (P <0.05). 45 weeks, 0.2% and 0.3 % and the control group, increased antibody titer to Newcastle, the difference was significant (P <0.05); improve the avian flu (H9) antibody titers, but the difference was not significant (P> 0.05).Conclusion: The results showed that: laying hens after peak, the overall balance in the nutrition diet add complex enzyme, the improvement of their economic effect is not obvious . Main reason: The economic characteristics of laying hens by dietary factors and changes decreased the sensitivity than the peak of egg production significantly, compensatory stronger, diets supplemented with enzyme preparation had no significantly improvement. The digestive tract of the environment and form layers, antioxidant capacity and major metabolic hormones. Even raising the layers of intestinal protease activity, immune function, reducing the amount of harmful bacteria, but these effects on health in terms of laying hens, but had no effect of improving production performance. Therefore, in the production practice of feeding ,nutritionally balanced diet routine after the laying hen egg production peaks, add complex enzyme is questionable.更多还原