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1.
本试验旨在研究低蛋白质(LP)饲粮中添加半胱氨酸(Cys)对肉仔鸡生长性能、胴体组成、血清生化指标及氮代谢的影响,以确定肉仔鸡LP饲粮中Cys的适宜添加水平。选取432只1日龄、体重相近的健康爱拔益加(AA)肉仔鸡公雏,随机分为6个组,每组6个重复,每个重复12只鸡。正对照(PC)组饲喂基础饲粮[前期(1~21日龄)和后期(22~42日龄)蛋白质水平分别为22%和20%],负对照(NC)组的蛋白质水平在PC组的基础上降低4.5个百分点(前期和后期蛋白质水平分别为17.5%和15.5%),Cys组在NC组的基础上分别添加0.05%、0.10%、0.15%和0.20%的Cys。各组前期和后期总含硫氨基酸水平分别为0.83%和0.79%。试验期42 d,分为前期和后期2个阶段。结果表明:1)饲粮蛋白质水平降低4.5个百分点,21和42日龄肉仔鸡的平均体重(ABW)、各生长阶段的平均日增重(ADG)和平均日采食量(ADFI)均显著降低(P0.05),试验前期的料重比(F/G)显著提高(P0.05);添加0.10%和0.15%Cys后,21和42日龄的ABW、试验后期和试验全期的ADG和ADFI均显著提高(P0.05),且均随Cys添加水平的提高呈线性和二次提高(P0.05),试验前期的F/G显著降低(P0.05),达到了与PC组相似的生长性能。2)饲粮添加Cys未见显著影响42日龄肉仔鸡的全净膛率(EP)和腿肌率(LMP)(P0.05),但有提高LMP的趋势(0.05≤P0.10);饲粮添加Cys线性和二次降低胸肌率(BMP)(P0.05),腹脂率(AFP)显著提高(P0.05)。3)饲粮添加Cys对21和42日龄肉仔鸡的血清生化指标无显著影响(P0.05)。4)饲粮添加Cys显著降低19~21日龄和40~42日龄肉仔鸡的氮摄入量、氮排泄量和氮存留量(P0.05),显著提高19~21日龄的氮存留率(P0.05)。5)二次曲线拟合结果表明,LP饲粮中Cys添加水平为0.13%~0.17%时,生长性能和氮代谢最佳。综上所述,LP饲粮中添加0.15%Cys能改善肉仔鸡的体增重、采食量和F/G,提高氮存留率;以生长性能和氮代谢为判断指标,推荐肉仔鸡LP饲粮中Cys的适宜添加水平为0.13%~0.17%(Cys占总含硫氨基酸的比例为45%~49%)。  相似文献   

2.
试验旨在研究山花黄芩提取物(SMF)对肉鸡生长性能、抗氧化性能及肉品质的影响。将180只1日龄的爱拔益加(AA)肉鸡(公雏)随机分为3组(对照组、阳性对照组、试验组),每组6个重复,每个重复10只鸡。阳性对照组饲喂添加125 mg/kg恩拉霉素(8%)的饲粮,试验组(SMF组)饲喂500 mg/kg SMF的饲粮,试验期1~42日龄。结果表明:SMF可在一定程度上提高1~21日龄平均日增重(ADG) 3.47%(P0.05),降低料重比(F/G)0.74%(P0.05),降低死淘率100%(P0.05);SMF可提高21~42日龄ADG 4.99%(P0.05)、降低(F/G) 4.41%(P0.05),降低死淘率50.07%(P0.05);SMF可在一定程度上提高1~42日龄ADG 3.10%(P0.05),降低F/G 1.69%(P0.05),显著降低死淘率66.70%(P0.05)。SMF可显著提高21 d肉仔鸡血清总抗氧化能力(T-AOC)(P0.05),显著提高42 d肉仔鸡血清谷胱甘肽过氧化物酶(GSH-Px)水平(P0.05)和超氧化物歧化酶(SOD)水平(P0.05),且均优于抗生素组;SMF可在一定程度上降低42 d肉仔鸡胸肌滴水损失、蒸煮损失及剪切力。由此可知,SMF对肉鸡1~42 d的生长性能、抗氧化性能及胸肌肉品质具有较好的提高作用,且可在一定程度上替代恩拉霉素。  相似文献   

3.
本试验旨在研究饲粮中添加不同水平维生素D3(VD3)对肉仔鸡生长性能及骨磷代谢利用的影响。试验选用480只1日龄艾拔益加肉公雏,采用2×4双因子完全随机设计,设2个饲粮非植酸磷水平[0.45%和0.23%(实测值为0.44%和0.21%)]与4个VD3添加水平(0、1 000、2 000和4 000IU/kg),共8个组,每组6个重复,每个重复10只鸡。试验期21d。结果表明,与0.21%非植酸磷水平相比,0.44%非植酸磷水平显著提高肉仔鸡平均日增重(ADG)、平均日采食量(ADFI)、胫骨灰分含量和胫骨灰分磷含量(P0.05),显著降低料重比(F/G)和胫骨灰分磷绝对沉积率(P0.05);与不添加VD3相比,饲粮中添加VD3显著提高肉仔鸡ADG、15~21和1~21日龄ADFI、胫骨灰分含量和胫骨灰分磷绝对沉积率(P0.05),显著降低1~21日龄肉仔鸡F/G(P0.05);0.21%非植酸磷水平下,与不添加VD3相比,饲粮中添加VD3显著降低肉仔鸡死亡率(P0.05),显著提高21日龄肉仔鸡胫骨灰分磷重量(P0.05),添加2000IU/kg VD3显著提高14日龄肉仔鸡胫骨灰分磷重量(P0.05);0.44%非植酸磷水平下,与不添加VD3相比,饲粮中添加VD3显著提高肉仔鸡胫骨灰分磷重量(P0.05)。以上结果表明,饲粮中添加VD3可提高肉仔鸡的生长性能并降低死亡率,促进磷在骨骼中的代谢利用。  相似文献   

4.
本试验旨在研究饲粮中添加β-丙氨酸对肉仔鸡生长性能、肉品质及胸肌中丙二醛和肌肽含量的影响。选取1日龄爱拔益加(AA)肉仔鸡公雏180只,随机分为3个组,每组6个重复,每个重复10只鸡,对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加500(βA5组)和1 000 mg/kgβ-丙氨酸(βA10组)的饲粮。试验期为42 d,分为前期(1~21日龄)和后期(22~42日龄)2个阶段。结果表明:1)与对照组相比,βA5和βA10组21日龄平均体重均显著提高(P0.05),42日龄平均体重分别提高30、72 g(P0.05);与对照组相比,βA5组后期、全期的平均日增重(ADG)均有提高趋势(0.05P0.10);βA5组前期、后期、全期的料重比(F/G)较对照组降低,其中前期、全期差异达显著水平(P0.05)。2)与对照组相比,βA5组胸肌滴水损显著降低(P0.05),24 h红度(a*)值显著提高(P0.05)。3)与对照组相比,βA5组胸肌中丙二醛(MDA)含量在屠宰后2和4 d呈下降趋势(2 d,P=0.091;4 d,P=0.059),βA5和βA10组胸肌中丙二醛含量在屠宰后6 d均显著降低(P0.05)。4)βA5和βA10组胸肉中肌肽含量较对照组显著提高(P0.05),分别提高了19.5%和14.4%。由此可见,饲粮中添加500 mg/kgβ-丙氨酸可改善肉仔鸡的生长性能,减少胸肌滴水损失,降低胸肌丙二醛含量,增加胸肌肌肽含量,改善肉品质。  相似文献   

5.
通过饲养试验和氮代谢试验,观测饲粮粗蛋白质水平对22~42日龄肉仔鸡生长性能、胴体性能及肉品质、血清生化指标、免疫功能、氮排放及氮表观利用率的影响,研究22~42日龄肉仔鸡玉米-豆粕型饲粮中粗蛋白质的最低需要量。采用单因子完全随机试验设计,将360只22日龄AA肉公雏按体重随机分成6个组,每个组10个重复笼,每个重复笼6只鸡,分别饲喂粗蛋白质实测水平为19.87%(对照组)、18.84%、17.63%、16.81%、15.75%和14.88%的玉米-豆粕型饲粮21 d。38~42日龄进行氮代谢试验。结果表明:耗料/增重、腹脂率、胸肌滴水损失和红度(a*)值、腿肌a*和黄度(b*)值、血清总胆固醇含量、甘油三酯含量、尿酸含量和氮表观利用率随饲粮粗蛋白质水平降低而显著提高(P0.05),而平均日增重、胸肌亮度(L*)值、新城疫抗体效价和氮排放随饲粮粗蛋白质水平降低而显著降低(P0.05)。与对照组相比,当饲粮粗蛋白质水平由19.87%降至17.63%时,上述指标无显著差异(P0.05),但显著降低粪便氮排放(P0.05);当饲粮粗蛋白质水平进一步降低至16.81%及以下时,肉鸡的平均日增重显著降低(P0.05),而耗料/增重显著提高(P0.05),腹脂率、胸肌滴水损失、血清总胆固醇和甘油三酯含量显著增加(P0.05),新城疫抗体效价显著降低(P0.05)。因此,22~42日龄肉仔鸡玉米-豆粕型饲粮中粗蛋白质最低需要量以17.63%为宜。  相似文献   

6.
本试验旨在研究常规饲养条件下,饲粮添加铬源与铬水平对0~3周龄肉仔鸡生长性能、胴体性能和肉品质的影响。选用252只1日龄体重均一的科宝(Cobb 500)肉仔鸡,随机分为7个处理,每个处理6个重复,每个重复6只鸡。各处理组分别饲喂玉米-豆粕型基础饲粮(含铬0.32 mg/kg)和在基础饲粮分别添加0.4、2.0 mg/kg铬分别源于丙酸铬(Cr Pro)、吡啶甲酸铬(Cr Pic)和三氯化铬(Cr Cl3)的试验饲粮,试验期为21 d。结果表明:铬源、铬水平及铬源与铬水平的互作对0~3周龄肉仔鸡的平均日采食量、平均日增重和饲料增重比及胴体性能均无显著影响(P0.10);不同铬源对胸肌亮度有显著影响(P0.10),Cr Pic组和Cr Cl3组分别较Cr Pro组显著提高了3.55%和3.76%(P0.05);铬源对胸肌红度也有显著影响(P0.10),与Cr Pic组相比较,Cr Pro组显著提高了32.72%(P0.10))。研究结果显示,饲粮中铬添加对0~3周龄肉仔鸡的生长性能及胴体性能无显著影响,不同铬源影响了肉仔鸡胸肌肉色,显著影响胸肌亮度和红度,其中以Cr Cl3提高亮度和Cr Pro提高红度效果较好。  相似文献   

7.
本试验旨在研究不同类型饲粮和添加剂对肉仔鸡生长性能、肠道结构和功能的影响。试验采用4×3两因子完全随机设计,4种饲粮分别为抗生素饲粮、无抗生素饲粮、低蛋白质饲粮和大麦饲粮,3种添加剂分别为酵母培养物(XPC)、谷氨酰胺(Gln)和大豆异黄酮(ISF)。试验选用1日龄爱拔益加肉仔鸡792只,随机分为12组,每组6个重复,每个重复11只鸡。试验期42 d。结果表明:1)不同类型饲粮分别添加XPC、Gln和ISF对42日龄肉仔鸡平均日增重(ADG)、平均日采食量(ADFI)、料重比(F/G)及体重(BW)的影响无显著差异(P0.05);但对饲粮类型而言,与其他3种饲粮相比,低蛋白质饲粮使肉仔鸡的BW、ADG和ADFI显著降低(P0.05),F/G显著提高(P0.05);抗生素饲粮显著降低肉仔鸡的F/G(P0.05)。饲粮类型与添加剂对肉仔鸡生长性能无显著的互作效应(P0.05)。2)与添加Gln相比,抗生素饲粮中添加ISF显著改善19日龄肉仔鸡回肠形态(P0.05);低蛋白质饲粮中添加XPC与添加其他2种添加剂相比对肉仔鸡回肠形态有显著改善作用(P0.05);与添加XPC相比,大麦饲粮中添加ISF显著改善19日龄肉仔鸡回肠形态(P0.05)。除35日龄肉仔鸡回肠隐窝深度外,饲粮类型与添加剂对回肠形态存在显著的互作效应(P0.05)。3)大麦饲粮中添加XPC比添加Gln和ISF显著提高35日龄肉仔鸡回肠干扰素-γ水平(P0.05);与添加ISF相比,抗生素饲粮中添加XPC可显著提高19日龄肉仔鸡回肠白细胞介素-10(IL-10)和免疫球蛋白A(Ig A)水平(P0.05),添加Gln可显著提高35日龄肉仔鸡回肠Ig A水平(P0.05);低蛋白质饲粮中添加XPC比添加其他2种添加剂显著提高19日龄肉仔鸡回肠Ig A水平(P0.05);无抗生素饲粮中添加ISF比添加XPC显著提高35日龄肉仔鸡回肠IL-10和Ig A水平(P0.05);而大麦饲粮中添加ISF比添加XPC显著降低35日龄肉仔鸡回肠IL-10水平(P0.05)。对于回肠IL-10和Ig A水平,饲粮类型与添加剂之间存在显著互作效应(P0.05)。4)抗生素饲粮中添加XPC比添加其他2种添加剂显著降低19日龄肉仔鸡粪便中氮和磷残留率(P0.05);无抗生素饲粮中添加XPC比添加其他2种添加剂显著提高19日龄肉仔鸡粪便中氮和磷残留率以及35日龄肉仔鸡粪便中磷残留率(P0.05);低蛋白质饲粮中添加XPC比添加Gln显著降低19日龄肉仔鸡粪便中氮残留率(P0.05);大麦饲粮中添加Gln比添加其他2种添加剂显著降低19日龄肉仔鸡粪便中氮和磷残留率(P0.05)。对氮、磷残留率而言,饲粮类型与添加剂之间存在显著互作效应(P0.05)。由此可见,4种类型饲粮中添加3种添加剂对1~42日龄肉仔鸡生长性能无显著影响;能氮比固定的低蛋白质饲粮降低了肉仔鸡的生长性能;低蛋白质饲粮中添加XPC可改善回肠形态结构;在不同类型饲粮中添加不同的添加剂具有改善肉仔鸡回肠免疫状态及降低粪便中氮磷残留率的趋势。  相似文献   

8.
本试验旨在探究不同能量水平饲粮中添加白酒糟酵母培养物对肉仔鸡生长性能、胴体组成和血清生化指标的影响。选用350只1日龄爱拔益加健康公雏,随机分为5个组,分别为:Ⅰ组(基础饲粮,对照组)、Ⅱ组(基础饲粮+0.5%白酒糟酵母培养物)、Ⅲ组(基础饲粮+1.0%白酒糟酵母培养物)、Ⅳ组(基础饲粮降低0.21 MJ/kg代谢能+0.5%白酒糟酵母培养物)和Ⅴ组(基础饲粮降低0.42 MJ/kg代谢能+1.0%白酒糟酵母培养物),每组7个重复,每个重复10只鸡。试验期42 d。结果显示:1)21日龄肉仔鸡平均体重以对照组最低,其他各组略有升高,Ⅲ组升高趋势明显(P0.10)。与对照组相比,Ⅱ组和Ⅳ组肉仔鸡22~42日龄料重比有所改善(P0.10),Ⅱ组料重比在1~42日龄低于对照组(P0.05)。2)与对照组比,Ⅳ组肉仔鸡21日龄腹脂率显著降低(P0.05),Ⅴ组肉仔鸡腹脂率在21日龄和42日龄有降低的趋势(P0.05)。3)饲粮添加白酒糟酵母培养物对肉仔鸡血清总蛋白、白蛋白、尿酸、肌酐、钙和磷含量影响均不显著(P0.05)。4)21日龄时,对照组肉仔鸡血清谷胱甘肽过氧化物酶(GSH-Px)活性最低,且显著低于Ⅱ组和Ⅳ组(P0.05);各试验组肉仔鸡血清超氧化物歧化酶活性显著高于对照组(P0.05),Ⅱ组和Ⅳ组肉仔鸡血清总抗氧化能力(T-AOC)显著高于对照组(P0.05)。42日龄时,各试验组肉仔鸡血清T-AOC均显著高于对照组(P0.05)。综上,不同能量水平饲粮中添加0.05%~0.10%白酒糟酵母培养物可提高肉仔鸡体增重,改善料重比,降低腹脂率,提高血清抗氧化能力。  相似文献   

9.
本试验旨在研究种鸡及子代肉仔鸡饲粮添加外源肌苷酸(IMP)对子代肉仔鸡生长性能、肉品质及相关基因表达的影响。选取遗传背景相同、体重相近、产蛋率达到5%的20周龄健康爱拔益加(AA)种鸡864羽,随机分为2组,每组6个重复,每个重复72羽。对照组饲喂基础饲粮,试验组在基础饲粮中添加0.5%肌苷酸,试验期30 d。试验结束前1周,母鸡产蛋率到达高峰期,连续收集7 d种蛋,共3 700枚种蛋孵化,孵化结束后,依据母代分组情况,选取孵化所得1日龄健康子代肉仔鸡3 000羽,分成4组,分别记为II(母代饲喂基础饲粮+0.5%肌苷酸,子代饲喂基础饲粮+0.5%肌苷酸)、IN(母代饲喂基础饲粮+0.5%肌苷酸,子代饲喂基础饲粮)、NI(母代饲喂基础饲粮,子代饲喂基础饲粮+0.5%肌苷酸)和NN组(母代饲喂基础饲粮,子代饲喂基础饲粮),每组6个重复,每个重复125羽。试验期42 d。结果表明:1)与NN组相比,II、IN和NI组子代肉仔鸡的平均日增重、平均日采食量和料重比均无显著差异(P0.05)。2)与NN组相比,II、IN和NI组子代肉仔鸡胸肌率和腿肌率均无显著差异(P0.05);II组腹脂率显著高于NI组(P0.05)。3)与NN组相比,II、IN和NI组子代肉仔鸡胸肌、腿肌的红度(a*)和黄度(b*)值均无显著差异(P0.05),II组胸肌的亮度(L*)值显著降低(P0.05);IN和NI组胸肌和腿肌pH45 min显著提高(P0.05),IN和NI组胸肌pH24 h显著提高(P0.05),II、IN和NI组腿肌pH24 h显著升高(P0.05)。4)与NN组相比,II、IN和NI组21和42日龄胸肌和腿肌的谷氨酰胺磷酸核糖焦磷酸酰胺转移酶(GPAT)基因相对表达量没有显著差异(P0.05),21日龄NI组胸肌和IN组腿肌的腺苷琥珀酸裂解酶(ADSL)基因相对表达量显著提高(P0.05),42日龄II和IN组胸肌的ADSL基因相对表达量显著提高(P0.05)。以上结果提示,种鸡及子代肉仔鸡饲粮添加外源肌苷酸对子代肉仔鸡生长性能、屠宰性能无显著影响;能够提高肌肉pH,降低胸肌L*值,提高胸肌ADSL基因表达量,在一定程度上能够提高子代肉仔鸡肉品质。  相似文献   

10.
本试验旨在研究饲粮中添加葡萄原花青素(GPC)对感染柔嫩艾美尔球虫肉仔鸡生长性能和免疫功能的影响。选用350只1日龄科宝-500(Cobb-500)健康肉仔鸡(公雏),随机分为5个组,每组7个重复,每个重复10只鸡。空白对照组和负对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮基础上添加7.5、15.0和30.0 mg/kg GPC的试验饲粮。14日龄时,负对照组和3个试验组每只肉仔鸡经口腔攻毒5×104个柔嫩艾美尔球虫卵囊,空白对照组每只肉仔鸡灌服同体积的生理盐水。试验期42 d,分为前期(1~21日龄)和后期(22~42日龄)2个阶段。结果表明:1)与空白对照组相比,负对照组肉仔鸡试验各阶段的平均日增重(ADG)均显著降低(P0.05),22~42日龄和1~42日龄时的料重比(F/G)显著增加(P0.05);饲粮中添加7.5和15.0 mg/kg GPC显著改善了柔嫩艾美尔球虫攻毒引起的22~42日龄和1~42日龄时ADG的降低和F/G的增加(P0.05);而饲粮中添加30.0 mg/kg GPC显著降低了22~42日龄时的ADG、平均日采食量(ADFI)和1~42日龄时的ADG(P0.05)。2)与负对照组相比,饲粮中添加GPC显著降低了肉仔鸡的盲肠病变评分、血便堆数和球虫卵囊排出数(P0.05)。3)饲粮中添加GPC显著抑制了柔嫩艾美尔球虫攻毒引起的肉仔鸡脾脏指数增加(P0.05);柔嫩艾美尔球虫攻毒引起T淋巴细胞转化率显著增加(P0.05),饲粮中添加7.5和15.0 mg/kg GPC使T淋巴细胞转化率进一步增加(P0.05);饲粮中添加7.5和15.0 mg/kg GPC可使B淋巴细胞转化率增加(P0.05);柔嫩艾美尔球虫攻毒引起外周血γδT细胞比例显著增加(P0.05),饲粮中添加15.0 mg/kg GPC使外周血γδT细胞比例进一步增加(P0.05)。4)与空白对照组相比,柔嫩艾美尔球虫攻毒显著增加了回肠上皮内淋巴细胞(IEL)数量和盲肠黏膜分泌型免疫球蛋白A(s Ig A)水平(P0.05),饲粮中添加7.5和15.0 mg/kg GPC使IEL数量和s Ig A水平进一步增加(P0.05)。综上所述,饲粮中添加GPC可提高感染柔嫩艾美尔球虫肉仔鸡的免疫功能,缓解柔嫩艾美尔球虫感染造成的生长抑制,其中7.5和15.0 mg/kg GPC的抗球虫效果较好。  相似文献   

11.
本研究分2个试验,旨在探讨低蛋白质补充合成氨基酸饲粮对肉仔鸡生长性能、氮排泄和胴体品质的影响.试验1选用600只1日龄爱拔益加肉仔鸡(公母各占1/2),分1~21 d,22~42 d和43~49 d 3个阶段饲养,饲粮共设5个处理,粗蛋白质水平分别为:生长前期(1~21 d):22.8%、21.9%、21.0%、19.5%和19.0%;生长中期(22~42 d):20.1%、18.8%、17.8%、16.5%和16.0%;生长后期(43~49 d):18.0%、16.9%、15.9%、15.0%和13.8%.各个处理蛋氨酸、赖氨酸和苏氨酸水平均满足NRC(1994)肉仔鸡营养需要.试验2的5组肉鸡饲粮的蛋白质水平与试验1的生长前期和生长中期饲粮相同,同时补充了足够的合成氨基酸以满足肉仔鸡对所有可消化必需氨基酸的需要量.结果表明:降低饲粮粗蛋白质水平同时补充合成氨基酸不影响试验1各个阶段肉仔鸡的生长性能(P>0.05).当以可消化氨基酸为基础配制饲粮时(试验2),生长前期肉仔鸡的日增重和饲料转化效率得到显著改善(P<0.01),但生长中期和生长全期肉仔鸡日增重和饲料转化效率差异不显著(P>0.05).降低饲粮粗蛋白质水平线性增加了试验1中肉仔鸡的脂肪沉积率(P<0.05),但对其他胴体指标没有显著影响(P>0.05).氮排泄随饲粮粗蛋白质水平的降低而线性减少(P<0.01).此外,降低饲粮粗蛋白质水平还降低了试验2中肉仔鸡血浆甘氨酸和苯丙氨酸的含量(P<0.05).综上所述,降低肉仔鸡饲粮粗蛋白质水平同时补充合成氨基酸可获得使用高蛋白质饲粮时的生长性能和胴体品质.  相似文献   

12.
Glycine has been reported to be conditionally essential for broilers fed reduced crude protein diets during the starter period. Research evaluating dietary Gly responses subsequent to the starter period is sparse. This experiment was conducted to ascertain the effects of feeding reduced crude protein diets supplemented with Gly and/or L-Gln (nitrogen source) on growth performance and carcass characteristics of broilers during a 41-day production period. Eight dietary treatments were utilized with the negative control diets formulated to contain approximately 2.4 and 0.29% points lower crude protein and total Gly + Ser concentrations, respectively, than the positive control diets. The 6 other diets were formulated to contain intermediate concentrations of total Gly + Ser and/or crude protein (nitrogen) by adding Gly and/or L-Gln, respectively, to the negative control diets. Glycine appeared to have more pronounced effects than nitrogen contribution on feed conversion ratio and body weight gain of broilers during starter and grower periods, whereas Gln improved feed conversion of broilers in the finisher period. Total breast meat weight and yield of broilers provided diets with the additions of Gly and L-Gln were higher than those receiving diets with only Gly or L-Gln supplementation. The positive outcomes on growth performance and carcass characteristics suggested that providing adequate total Gly + Ser and nitrogen concentrations in diet formulation may be necessary for broilers when dietary CP content was reduced approximately by 2.4% points during a 6-week production period.  相似文献   

13.
本试验旨在研究蒙脱石对采食天然黄曲霉素毒素B1(AFB1)污染花生粕型饲粮的肉仔鸡生长性能和免疫机能的影响,确定蒙脱石作为霉菌吸附剂的饲用效果。选用288只1日龄爱拔益加(AA)健康公雏,随机分为4组,每组6个重复,每个重复12只鸡。正对照组饲喂玉米-豆粕型基础饲粮,负对照组饲粮用自然霉变花生粕(含AFB11 284.21μg/kg;前期、后期饲粮分别添加8.8%和12.0%)替代部分豆粕,试验组分别在负对照组饲粮中添加2.0 g/kg的天然或改性蒙脱石。试验期42 d。结果表明:1)与正对照组相比,霉变花生粕显著降低了肉仔鸡平均日增重(ADG)、平均日采食量(ADFI)、42日龄胸肌率和腿肌率以及血浆蛋白含量(P0.05),显著提高了料重比和免疫器官指数(P0.05)。2)与负对照组相比,天然或改性蒙脱石均显著提高了肉仔鸡ADG、ADFI及血浆蛋白含量(P0.05),显著降低了免疫器官指数(P0.05)。3)与天然蒙脱石组相比,改性蒙脱石显著提高了肉仔鸡ADG及血浆总蛋白和白蛋白含量(P0.05),显著降低了胸腺指数(P0.05)。综上,AFB1污染的霉变花生粕能降低肉仔鸡的生长性能和免疫功能,蒙脱石能缓解AFB1引起的不良影响,改性蒙脱石作用效果更佳。  相似文献   

14.
Two experiments were conducted to determine the efficacy of mannan oligosaccharides (MOS) fed at two levels of Cu on growth and feed efficiency of weanling and growing-finishing pigs, as well as the effect on the immunocompetence of weanling pigs. In Exp. 1, 216 barrows (6 kg of BW and 18 d of age) were penned in groups of six (9 pens/treatment). Dietary treatments were arranged as a 2 x 2 factorial consisting of two levels of Cu (basal level or 175 ppm supplemental Cu) with and without MOS (0.2%). Diets were fed from d 0 to 38 after weaning. Blood samples were obtained to determine lymphocyte proliferation in vitro. From d 0 to 10, ADG, ADFI, and gain:feed (G:F) increased when MOS was added to diets containing the basal level of Cu, but decreased when MOS was added to diets containing 175 ppm supplemental Cu (interaction, P < 0.01, P < 0.10, and P < 0.05, respectively). Pigs fed diets containing 175 ppm Cu from d 10 to 24 and d 24 to 38 had greater (P < 0.05) ADG and ADFI than those fed the basal level of Cu regardless of MOS addition. Pigs fed diets containing MOS from d 24 to 38 had greater ADG (P < 0.05) and G:F (P < 0.10) than those fed diets devoid of MOS. Lymphocyte proliferation was not altered by dietary treatment. In Exp. 2, 144 pigs were divided into six pigs/pen (six pens/treatment). Dietary treatments were fed throughout the starter (20 to 32 kg BW), grower (32 to 68 kg BW), and finisher (68 to 106 kg BW) phases. Diets consisted of two levels of Cu (basal level or basal diet + 175 ppm in starter and grower diets and 125 ppm in finisher diets) with and without MOS (0.2% in starter, 0.1% in grower, and 0.05% in finisher). Pigs fed supplemental Cu had greater (P < 0.05) ADG and G:F during the starter and grower phases compared to pigs fed the basal level of Cu. During the finisher phase, ADG increased when pigs were fed MOS in diets containing the basal level of Cu, but decreased when MOS was added to diets supplemented with 125 ppm Cu (interaction, P < 0.05). Results from this study indicate the response of weanling pigs fed MOS in phase 1 varied with level of dietary Cu. However, in phase 2 and phase 3, diets containing either MOS or 175 ppm Cu resulted in improved performance. Pharmacological Cu addition improved gain and efficiency during the starter and grower phases in growing-finishing pigs, while ADG response to the addition of MOS during the finisher phase seems to be dependent upon the level of Cu supplementation.  相似文献   

15.
The purpose of this investigation was to compare the growth performance of grower pigs fed low-CP, corn-soybean meal (C-SBM) AA-supplemented diets with that of pigs fed a positive control (PC) C-SBM diet with no supplemental Lys. Five experiments were conducted with Yorkshire crossbred pigs, blocked by BW (average initial and final BW were 21 and 41 kg, respectively) and assigned within block to treatment. Each treatment was replicated 4 to 6 times with 4 or 5 pigs per replicate pen. Each experiment lasted 28 d and plasma urea N was determined at the start and end of each experiment. All diets were formulated to contain 0.83% standardized ileal digestible Lys. All the experiments contained PC and negative control (NC) diets. The PC diet contained 18% CP and was supplemented with only DL-Met. The NC diet contained 13% CP and was supplemented with L-Lys, DL-Met, L-Thr, and L-Trp. The NC + Ile + Val diet was supplemented with 0.10% Val + 0.06% Ile. The NC + Ile + Val diet was supplemented with either His (Exp. 1), Cys (Exp. 2), Gly (Exp. 2, 3, and 4), Glu (Exp. 3), Arg (Exp. 4), or combinations of Gly + Arg (Exp. 4 and 5) or Gly + Glu (Exp. 5). Treatment differences were considered significant at P < 0.10. In 3 of the 4 experiments that had PC and NC diets, pigs fed the NC diet had decreased ADG and G:F compared with pigs fed the PC diet. The supplementation of Ile + Val to the NC diet restored ADG in 4 out of 5 experiments. However, G:F was less than in pigs fed the PC diet in 1 experiment and was intermediate between the NC and PC diets in 3 experiments. Pigs fed supplemental Ile + Val + His had decreased G:F compared with pigs fed the PC. Pigs fed supplemental Cys to achieve 50:50 Met:Cys had decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.224% supplemental Gly had similar ADG, greater ADFI, and decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.52% supplemental Gly had ADG and G:F similar to that of pigs fed the PC. Pigs fed supplemental Glu had decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.48% supplemental Arg had decreased G:F compared with pigs fed the PC. Pigs fed the diet supplemented with Gly + Arg had ADG and G:F similar to pigs fed the PC. Pigs fed the low-CP diets had reduced plasma urea N compared with pigs fed PC. The results of these experiments indicate that supplementing Gly or Gly + Arg to a low-CP C-SBM diet with 0.34% Lys, Met, Thr, Trp, Ile, and Val restores growth performance to be similar to that of pigs fed a PC diet with no Lys supplementation.  相似文献   

16.
反10,顺12共轭亚油酸对肉仔鸡肉品质和相关酶活的影响   总被引:1,自引:0,他引:1  
选择1 d健康AA肉仔鸡288只,研究不同水平反10,顺12共轭亚油酸(t-10,-c12 CLA)对肉仔鸡生长性能、肉品质、相关激素和酶活性的影响。试验采用单因素随机设计,将试验鸡随机分成6组,每组6个重复,每个重复8只鸡,分别饲喂0、0.20%、0.40%、0.60%、0.80%和1.00%t-10,-c12 CLA的玉米-豆粕型饲粮,试验期42 d。结果表明,饲粮CLA对肉鸡全期日增重、饲料转化率有显著影响(P〈0.05),极显著降低了腹脂率(P〈0.01),对采食量、胸肌率、腿肌率、胸肌和全净膛率均无显著影响(P〉0.05);饲粮CLA对肉鸡肉色b*值、剪切力和胸肌的品尝评价有显著影响(P〈0.05),对pH、肉色L*、a*值和腿肌品尝评价无显著影响(P〉0.05);饲粮CLA对肉鸡血清胰岛素l、eptin(P〈0.05)和组织中苹果酸脱氢酶(P〈0.01)有显著影响。饲粮t-10,c-12 CLA可提高肉仔鸡的饲料转化率和日增重,对肉品质剪切力和品尝有改善作用;CLA降低腹脂率,增加了肌内脂肪的含量,可能与leptin浓度和苹果酸脱氢酶活性有关。  相似文献   

17.
An experiment was conducted to evaluate increasing or decreasing concentrations of dietary phytase on growth performance and processing yields of male broilers from 1 to 35 d of age. Treatments consisted of a positive control, a negative control (NC; less 0.14% Ca, 0.13% nonphytate P, and 0.03% Na), and 6 additional treatments based on the NC supplemented with phytase. Treatments 3 through 5 consisted of the NC diet supplemented with 500 phytase units (FTU)/kg of phytase in the starter phase that was either continued throughout the remainder of the study (treatment 3) or increased to 1,500 FTU/kg beginning in the finisher (treatment 4) or grower (treatment 5) phases. Treatment 6 had 1,500 FTU/kg of phytase throughout the study. Treatments 7 and 8 had 1,500 FTU/kg in the starter and decreased to 500 FTU/kg in the finisher or grower phases, respectively. At 35 d of age, broilers fed diets containing 1,500 FTU/kg of phytase had increased BW gain compared with birds fed diets formulated to contain 500 FTU/kg of phytase. Increasing phytase concentration between the starter and grower phases or decreasing phytase concentration between the grower and finisher phases negatively affected FCR from 1 to 35 d of age. Phytase supplementation did not affect weight and yield of carcass characteristics. Therefore, dietary phytase concentration should not be varied throughout production for optimum growth performance.  相似文献   

18.
试验旨在研究灭活乳酸菌培养物对肉鸡生长性能及免疫功能的影响。选择300只体重相近的健康1日龄AA肉仔鸡,随机分为5组,每组6个重复,每个重复10只鸡,雌、雄各半。其中对照组饲喂基础日粮,抗生素组在基础日粮中添加0.01%金霉素,乳酸菌培养物组分别在基础日粮中添加0.16%乳酸菌培养物L1、L2、L3。试验期42 d,分1~21日龄(前期)和22~42日龄(后期)2个阶段。结果显示,1~21日龄时,乳酸菌培养物L1组肉鸡平均日采食量极显著高于对照组和抗生素组(P<0.01),血清中白介素-2(IL-2)含量显著低于对照组(P<0.05),脾脏指数、胸腺指数、法氏囊指数均显著高于对照组(P<0.05);乳酸菌培养物L2组肉鸡脾脏指数、胸腺指数显著高于对照组(P<0.05);乳酸菌培养物L3组肉鸡平均日增重极显著高于对照组和抗生素组(P<0.01);抗生素组肉鸡血清中γ-干扰素(IFN-γ)含量显著高于乳酸菌培养物组(P<0.05)。22~42日龄时,乳酸菌培养物L1、L2组肉鸡平均日增重极显著高于对照组和抗生素组(P<0.01);乳酸菌培养物L2组肉鸡血清中免疫球蛋白G(IgG)含量显著高于抗生素组(P<0.05),血清新城疫抗体效价及脾脏指数、胸腺指数、法氏囊指数均显著高于对照组(P<0.05);乳酸菌培养物L3组肉鸡血清中免疫球蛋白A(IgA)含量及胸腺指数显著高于对照组(P<0.05)。由此可知,在肉鸡日粮中添加一定量的灭活乳酸菌培养物可在一定程度上提高肉鸡的生长性能、增强其免疫功能,其中,对于提高肉鸡的生长性能,试验前期添加L3效果较好,试验后期添加L1和L2效果较好;对于增强肉鸡的免疫功能,试验前期添加L1效果较好,试验后期添加L2效果较好。  相似文献   

19.
The experimental design consisted of 5 dietary treatments including a positive control (PC), a negative control (NC; with a reduction of 88 kcal/kg of AME through the starter and grower 1 phase and a reduction of 132 kcal/kg of AME in the grower 2, finisher, and withdrawal phases compared with the PC), and the NC supplemented with either β-mannanase, nonstarch polysaccharide-degrading enzymes (NSPase; cocktail carbohydrase), or β-mannanase and NSPase intermittently fed. The intermittent treatment included β-mannanase from d 1 to 21 (starter and grower 1 phases) and NSPase from d 22 to 47. Each treatment included 9 replicate pens with 35 male broilers placed per replicate (1,575 total chicks placed). The dietary program consisted of 5 dietary phases, including the starter through d 10, grower 1 through d 21, grower 2 through d 32, finisher through d 40, and withdrawal through d 47. Broilers were weighed and feed consumption determined on days of dietary changes. On d 48, following an 8-h feed withdrawal, 6 broilers from each replicate pen were removed and processed for whole bird and fat pad measurements. The reduction in energy in the NC diet reduced BW and increased mortality rate, and the inclusion of β-mannanase and NSPase separately and intermittently in the NC diet improved growth performance and reduced mortality to levels that were comparable to the PC. The NC yielded the highest cumulative mortality-corrected FCR and all enzyme inclusion treatments reduced FCR to levels comparable to the PC for the duration of the trial. The NC diet yielded the lowest processing yields and the inclusion of β-mannanase and NSPase separately and intermittently increased multiple processing parameters to a level similar to the PC. These data confirm the ability of β-mannanase and NSPase inclusion separately and intermittently to improve performance parameters in reduced-energy broiler diets.  相似文献   

20.
The objective of the current study was to evaluate the effect of feeding a thermo-tolerant xylanase in low-energy broiler diets on performance and processing parameters. Evaluation criteria included average broiler BW, FCR, livability, carcass yield, and fat pad yields. The experimental design consisted of 3 nutrient profiles: positive control, negative control 1 (−66 kcal/kg), and negative control 2 (−132 kcal/kg). Two xylanase inclusion programs were included in the negative control 1 and 2 diets; 60 g/t was included in the starter and grower diets with either 60 or 100 g/t in the finisher and withdrawal diets, yielding a total of 7 treatment groups with 8 replicate pens per treatment each containing 42-d-old straight-run chicks per treatment (2,352 total broilers). Broilers were reared in floor pens through 45 d of age. The dietary program consisted of 5 dietary phases: starter (1–15 d), grower 1 (16–23 d), grower 2 (24–31 d), finisher (32–38 d), and withdrawal (39–45 d). Body weights and feed consumption were determined on days of dietary changes, including d 15, 23, 31, 38, and 45. On d 45, 4 male and 4 female broilers per replicate (448 total) were subjected to an 8-h feed withdrawal period and processed to obtain carcass and fat pad weights. Reducing the dietary energy level increased FCR and decreased the fat pad weight of broilers in the negative control 2 treatment compared with the positive control. Inclusion of xylanase during the starter phase increased d 15 BW and reduced FCR. The inclusion of xylanase continued to reduce FCR throughout the trial, as compared with diets without xylanase inclusion. Within this study, we have demonstrated the effectiveness of xylanase inclusion in reduced-energy diets (−66 and −132 kcal/kg) to improve FCR of broilers to that of broilers fed energy-adequate diets.  相似文献   

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