【作者】 王斯佳；

【导师】 蔡辉益；

【作者基本信息】 中国农业科学院 ， 动物营养与饲料科学， 2012， 博士

【摘要】 本课题围绕胆碱生物学效价、肉鸡对胆碱的代谢与需要量展开研究，分别探究了常规饲料原料中胆碱的生物利用率、不同饲养阶段肉鸡胆碱和蛋氨酸的最佳添加水平、肉鸡对以氯化胆碱形式补充的胆碱的吸收代谢规律。旨在为生产实践提供更详尽的理论依据的同时，也为动物营养物质需要量的研究提供新的方法和思路。试验一不同饲料原料中胆碱生物学效价的评定本研究采用斜率比法对玉米、豆粕、菜粕和玉米酒精糟（DDGS）中胆碱的生物学效价（RBV）进行了评估。试验选用１日龄爱拔益加（ＡＡ）肉仔鸡132只，随机分为22个处理，其中S1^S6组为标准曲线组，A1^A4组为玉米日粮组，B1^B4组为豆粕日粮组，C1^C4为菜粕日粮组，D1^D4为DDGS日粮组，每个处理6个重复，每个重复1只鸡。基础日粮采用醇提法将玉米、豆粕、菜粕和DDGS中的胆碱洗脱后配制而成。在基础日粮中添加不同剂量的氯化胆碱配制6种梯度的标准日粮；另将4种待测原料分别以10%、20%、40%和100%的比例替换洗脱过的相应原料配制试验日粮。分别以1²1日龄的平均日增重、肝脏脂肪含量和全血胆碱浓度为衡量指标，以比斜率法计算待测原料的相对生物学利用率，试验期21天。结果显示：以平均日增重为指标，玉米、豆粕、菜粕和DDGS中胆碱RBV分别为：63.95%、104.7%、37.98%和72.09%；以全血胆碱浓度为指标，玉米、豆粕和DDGS中胆碱RBV分别为：94.73%、184.11%和134.23%。以日增重和全血胆碱含量为指标衡量饲料原料中胆碱生物学效价是可行的，但由于选择指标的不同，所得数值亦有所差异。4种参试原料中胆碱的相对生物学利用率从高到低依次为：豆粕、DDGS、玉米和菜粕。试验二口服不同剂量氯化胆碱在肉鸡体内的代谢动力学研究本试验旨在采用药代动力学的研究手段，探索氯化胆碱在肉鸡体内的吸收代谢规律。试验选用12只9周龄的AA肉公鸡，按体重分别单次口服氯化胆碱200和400mg/kg（以胆碱计算），并做空白对照。采取血样，对血样中的胆碱浓度进行离子色谱法的测定，并用药动学处理软件WinNonlin5.2中的非房室模型方法计算药代动力学参数。结果显示，空白对照组内源胆碱的合成水平基本稳定；不同灌喂剂量的氯化胆碱在肉鸡体内药动学过程存在差异，表观分布容积Vz/F和血药表观清除率CLz/F差异极显著（P<0.01）；灌喂剂量在200⁴00mg/kg内，胆碱的药动学行为呈线性关系。肉鸡口服两种剂量的主要药动学参数如下。200mg：t_max为8.0h，C_max为399.88mg/kg，t_1/2为7.60h，AUC_0-∞为5979.06mg·h/kg，Vz/F为876.99L/kg，CLz/F为83.27mg/h/kg；400mg：t_max为8.0h，C_max为445.88mg/kg，t1/2为9.91h，AUC_0-∞为10899.78mg/h/kg，Vz/F为318.43L/kg，CLz/F为21.22mg/h/kg。200mg剂量的胆碱更易进入细胞用于物质的生物合成。提示单纯依靠增加氯化胆碱剂量无法实现提高胆碱生物利用率的目的。试验三二次正交旋转组合设计优化1²1日龄肉仔鸡胆碱和蛋氨酸需要量的研究本试验以低胆碱、低蛋氨酸日粮为基础日粮，通过两因子二次回归正交旋转组合设计，旨在研究1²1日龄肉仔鸡胆碱和蛋氨酸的最佳需要量。试验选用1日龄爱拔益加（AA）肉仔鸡480只，随机分为12个处理，其中1⁸组为试验组，9¹2组为中心组，每个处理4个重复，每个重复10只鸡，公母各半。分别以胆碱和蛋氨酸为自变量，以反映肉仔鸡生长性能和屠宰性能的各项指标为因变量拟合回归方程，估计1²1日龄肉仔鸡胆碱和蛋氨酸需要量。试验期21d。结果表明：一定水平的胆碱和蛋氨酸可显著改善1²1日龄肉仔鸡的平均日增重、料肉比、屠宰率和腹脂率。当蛋氨酸水平为0.5⁰.7%时，随着胆碱水平的降低，肉仔鸡平均日增重逐渐降低；当蛋氨酸水平为0.42⁰.5%，胆碱水平为1300¹738mg/kg时，肉仔鸡的料重比达到最低；蛋氨酸水平为0.5⁰.7%时，屠宰率随着蛋氨酸水平的升高而下降，蛋氨酸为0.36⁰.5%时，随着胆碱水平的升高，屠宰率呈上升趋势；随着胆碱水平的升高，腹脂率逐渐降低；当胆碱水平在1300¹920mg/kg时，腹脂率随蛋氨酸水平的降低而下降。在本试验条件下，当胆碱水平为1434¹631mg/kg，蛋氨酸水平为0.47%时，肉仔鸡可达到最佳生长性能；当胆碱水平为1984mg/kg，蛋氨酸水平为0.49%时，肉仔鸡可达到最佳屠宰性能。试验四二次正交旋转组合设计优化21⁴2日龄肉仔鸡胆碱和蛋氨酸需要量的研究本试验以低胆碱、低蛋氨酸日粮为基础日粮，通过二元二次正交旋转组合设计，对21⁴2日龄肉仔鸡胆碱和蛋氨酸需要量进行研究。试验选用21日龄爱拔益加（AA）肉仔鸡480只，随机分为12个处理，其中1⁸组为试验组，9¹2组为中心组，每个处理4个重复，每个重复10只鸡，公母各半。分别以胆碱和蛋氨酸为自变量，以反映肉仔鸡生长性能和屠宰性能的各项指标为因变量拟合回归方程，估计21⁴2日龄肉仔鸡胆碱和蛋氨酸的需要量。试验期21d。结果表明，胆碱和蛋氨酸水平对21⁴2日龄肉仔鸡的日平均采食量、料重比、腹脂率和肝脏脂肪含量有显著影响。当胆碱水平在860¹120mg/kg，肉仔鸡平均日采食量随着蛋氨酸的添加而升高，蛋氨酸水平增至0.4%后，继续增加对采食量的改善作用不明显；蛋氨酸水平在0.35⁰.42%，胆碱水平在860¹120mg/kg时，肉鸡的料重比达到最低值；蛋氨酸水平为0.3⁰.47%，随着胆碱的增加肉鸡腹脂率呈下降趋势；当蛋氨酸水平为0.3⁰.4%，胆碱水平为1000¹400mg/kg时，肉鸡肝脏脂肪含量随着胆碱的增加和蛋氨酸的降低呈下降趋势。在本试验条件下，当胆碱水平为990¹030mg/kg，蛋氨酸水平为0.4⁰.43%时，肉仔鸡可达到最佳生长性能；当胆碱水平为1780¹880mg/kg，蛋氨酸水平为0.37⁰.38%时，肉仔鸡可达到最佳屠宰性能。更多还原

【Abstract】 In order to investigate the choline requirement of broiler, three trials were conducted, including theoptimal choline requirement level of of broiler; the bioavailability of choline in the feedstuffs; and thecholine chloride absorption and metabolism in broiler. It was expected to provide more detailedtheoretical basis for the practial production, as well as to offer a new methods and ideas for the researchof nutrient requirement from multiple perspectives.Exp.1Evaluate the Bioavailability of Choline in Various FeedstuffsThis Study was conducted to evaluate the relative biological value （RBV） of choline in corn, soybeanmeal, canola meal and distillers dried grains with soluble （DDGS）. A total of132one-day-old broilerswere divided into22groups （6replicates per group and each replicate had1broiler）. Groups S1-S6were standard curve group, Groups A1-A4were corn groups, Group B1-B4were soybean meal groups,Group C1-C4were canola meal groups, and Groups D1-D4were DDGS groups. The basic dietcontained the four feedstuffs above with lowered choline content through being extracted withmethanol/alcohol. All the test diets had the same composition as that of the basic diet except cholinecontent. A choline response curve was generated using crystalline choline chloride added to the basicdiet. The experiment diets were made from the basic diet in which the washed feedstuff was replacedwith the intact one with10%,20%,40%, and100%. In the slope ratio assays to determine cholineavailability, measured by average daily gain （ADG） and choline concentration in blood. The experimentlasted for21d. Using ADG as response criterion, the choline RBV of corn, soybean meal, canola meal,and DDGS were:63.95%,104.7%,37.98%, and72.09%; using choline concentration in blood asresponse criterion, the RBV of corn, soybean meal, and DDGS were:94.73%,184.11%, and canolameal,37.98%,134.23%.It is possible to evaluate the bioavailability of choline in feedstuffs using ADGand choline concentration in blood as criteria. But the values will be different in different criteria. Fromhigh to low, choline RBV of the four feedstuffs were soybean meal, DDGS, corn and canola meal,respectively.Exp.2Pharmacokinetic Study of Choline Chloride in Broiler by Oral AdministrationTo compare the pharmacokinetics of choline chloride in broiler after oral administration of differentdoses, a study was conducted.12male broilers received0,200,400mg/kg of choline （the form ofcholine chloride） by oral administration, respectively. Every treatment had4duplicates. Every duplicatehad1broiler. We took blood in different time according to the experimental design. The bloodconcentration of the choline was analyzed by ion chromatography. The pharmacokinetics parameterswere calculated by WinNonlin5.2using non-compartment model.The result showed that, endogenoussynthesis of choline was stable. The pharmacokinetics of choline chloride at the two doses was different,which was significant difference on Vz/F and CLz/F （P<0.01）. It showed linear pharmacokinetics in broilers, when the dose was200to400mg/kg. The pharmaceutical parameters in broilers after singleadministration of the two doses of choline chloride orally were as follow.200mg: t_maxC_maxt1/2AUC_0-∞Vz/F and CLz/F were8.0h,399.88mg/kg,7.60h,5979.06mg/h/kg,876.99L/kg,83.27mg/h/kg;400mg: t_maxC_maxt1/2AUC_0-∞Vz/F and CLz/F were8.0h,445.88mg/kg,9.91h,10899.78mg/h/kg,318.43L/kg,21.22mg/h/kg. The dose of200mg had more possibility to enter to cell, inwhere the choline can be used to biosynthesize. We concluded that it was impossible that to enhancingthe bioavailability of choline only relying on increasing the dose of choline chloride.Exp.3Requirement of Choline and Methionine of Broiler Aged1to21Days by QuadraticOrthogonal Rotation Combination DesignA research on choline and methionine requirements for broilers aged1to21days were carried out. Atotal of480one-day old broilers were divided into12groups （4duplicates per group and each duplicatehad10broilers） in random. A diet with low level of choline and methionine was used as the basic diet inthis experiment, in which the contents of choline and methionine were680mg/kg and0.30%,respectively. To study the influence of different choline and methionine levels on growth performanceand slaughter performance, a two-factor combinational design of quadratic regression and orthogonalrotation was used. The results showed that a certain levels of choline and methionine could improveADG, F/G, dressing percentage and abdominal fat percentage of broiler aged1to21days. Whenmethionine levels were0.5⁰.7%, ADG of broilers was decreased with the reduction of choline levels.When the methionine levels were0.42⁰.5%, the choline levels were1300¹738mg/kg, F/G wasminimum. When methionine levels were0.5⁰.7%, the dressing percentage was decreased with theincreasing methionine levels; methionine were0.36⁰.5%, the dressing percentage was improved withthe addition of choline. Abdominal fat percentage was decreased with the rise of the choline levels;when choline levels were1300¹920mg/kg, abdominal fat percentage was decreased with thereducing methionine. It could be concluded that the requirements of choline and methionine for optimalgrowth performance were1434¹631mg/kg and0.47%. The requirements of choline and methioninefor optimal carcass performance were1984mg/kg and0.49%.Exp.4Requirement of Choline and Methionine of Broiler Aged21to42Days by QuadraticOrthogonal Rotation Combination DesignA research on choline and methionine requirements for broilers aged21to42days were carried out.A total of48021-day old broilers were divided into12groups （4duplicates per group and eachduplicate had10broilers） in random. A diet with low level of choline and methionine was used as thebasic diet in this experiment, in which the contents of choline and methionine were600mg/kg and0.30%respectively. To study the influence of different choline and methionine levels on growthperformance and slaughter performance, a two-factor combinational design of quadratic regression andorthogonal rotation to study the influence on production and slaughter performance in different choline and methionine was used. The results showed that choline and methionine have significant effects onADFI, F/G, abdominal fat and lowest liver fat of21to42days broilers. When choline levels were860¹120mg/kg, ADFI was enhanced with the rise of methionine, till the levels of methionine added at0.4%. When the methionine were0.35⁰.42%, choline were860¹120mg/kg, F/G was minimum.When methionine were0.3⁰.47%, abdominal fat percentage was decreased with the rise of the cholinelevels. When the levels of methionine were0.30⁰.40%，choline were1000¹400mg/kg, the liver fatof broilers was decreased with the rise of choline and the reducing methionine. In this experiment,choline and methionine requirements for best growth performance of broilers aged21to42days were990-1030mg/kg and0.40-0.43%, respectively. For best slaughter performance, choline and methioninerequirements were1780-1880mg/kg and0.37-0.38%, respectively.更多还原