Dietary Copper Supplemental Level Affects Performance and Melanin Content in Tissues of Taihe Silky Fowls

本试验旨在研究饲粮铜添加水平对1 ～28日龄泰和乌骨鸡生产性能和组织黑色素含量的影响.选用1日龄泰和乌骨鸡270只,随机分成6组,每组设3个重复,每个重复15只鸡.试验鸡分别饲喂在基础饲粮(铜含量为4.75 mg/kg)中添加0、5、15、30、60、125 mg/kg铜的饲粮,饲养至28日龄.结果表明:饲粮铜不同添加水平对1 ～ 28日龄泰和乌骨鸡平均日增重、平均日采食量和料重比均无显著影响(P＞0.05),但适量添加可显著或极显著影响其血清、肝脏、肾脏、皮肤及肌肉的黑色素含量、酪氨酸酶活性(P＜0.05或P＜0.01),并呈现出随饲粮铜添加水平的提高先升后降的趋势.当饲粮铜添加水平为30 mg/kg时,泰和乌骨鸡血清和组织酪氨酸酶活性及黑色素含量达到峰值.由此可知,玉米-豆粕型基础饲粮中添加铜可提高泰和乌骨鸡组织黑色素含量,其适宜添加水平为30 mg/kg.     

饲粮铜添加水平对5～8周龄泰和乌骨鸡生产性能及组织黑色素含量的影响

本试验旨在研究饲粮铜添加水平对5～8周龄泰和乌骨鸡生产性能及组织黑色素含量的影响。选用29日龄泰和乌骨鸡270只,随机分成6组,每组3个重复,每个重复15只鸡。试验鸡饲喂在基础饲粮(铜含量为4.77 mg/kg)中分别添加0、5、15、30、60、125 mg/kg铜的饲粮,饲养至56日龄。结果表明:饲粮添加适量铜可显著影响5～8周龄泰和乌骨鸡平均日增重、平均日采食量和料重比(P<0.05),且在30 mg/kg时生产性能达到最佳。饲粮添加适量铜可显著或极显著影响血清、肝脏、肾脏、皮肤及肌肉的黑色素含量及酪氨酸酶活性(P<0.05或P<0.01),并呈现出随饲粮铜添加水平的提高先升后降的趋势。当饲粮铜添加水平为30 mg/kg时,血清和组织酪氨酸酶活性及组织黑色素含量达到峰值。由此可知,玉米-豆粕型基础饲粮中添加铜可提高生产性能和组织黑色素含量,其适宜添加水平为30 mg/kg。     

不同铜源及水平的日粮对产蛋鸡生产性能及蛋品质的影响

用６８周龄海赛克斯蛋鸡,研究玉米－大豆粕－棉仁粕型日粮中添加５水硫酸铜（ＣｕＳＯ４．５Ｈ２Ｏ）形式的铜６ｍｇ／ｋｇ、３０ｍｇ／ｋｇ、６０ｍｇ／ｋｇ、１２５ｍｇ／ｋ和柠檬酸铜（ＣｕＣｉｔ）形式的铜６ｍｇ／ｋｇ、３０ｍｇ／ｋｇ、６０ｍｇ／ｋｇ试验结果表明：与对照组经（含铜６．４ｍｇ／ｋｇ）,日粮中添加６ｍｇ／ｋｇＣｕ（硫酸铜）时耗料最低,蛋壳厚度最大,且随着添加量的增加蛋壳厚度变薄;日粮中添加３０ｍｇ／ｋｇＣｕ（硫酸铜）时产蛋率最高,料蛋比最低,蛋壳强度最大,日粮中添加不同铜源及水平对蛋黄铜含量的影响不大（Ｐ〉０．０５）。与对照组相比,日粮中添加１２５ｍｇ／ｋｇＣｕ（硫酸铜）时肝脏铜水平明显升高（Ｐ〈０．０５）,但各添加组之间的差异不显著（Ｐ〉０．０５）。随着日粮中铜添加水平的提高,蛋黄和肝脏胆固醇水平显著降低（Ｐ     

不同化学形式的铜对仔猪生长、消化和胴体组成的影响

１８０头“杜长大”仔猪（２１．３４±０．４４ｋｇ）,按试验要求分为６组,分别饲喂添加５ｍｇ／ｋｇ、５０ｍｇ／ｋｇ、２４０ｍｇ／ｋｇ无机铜（硫酸铜）、５０ｍｇ／ｋｇ酪蛋白铜、５０ｍｇ／ｋｇ奶蛋白铜和５０ｍｇ／ｋｇ大豆蛋白铜的饲粮,试验为期３０天。结果表明：①饲粮中添加不同化学形式的铜均提高了日增重,降低了料重比,其中以５０ｍｇ／ｋｇ酪蛋白铜组最佳,日增重比对照组（５ｍｇ／ｋｇ硫酸铜）提高了１３．６％（Ｐ＜０．０５）,料重比下降了９．５％,其次为２４０ｍｇ／ｋｇ无机铜组,日增重提高了１２．５％（Ｐ＜０．０５）,料重比下降了８．３％（Ｐ＜０．０５）。②添加不同化学形式铜均提高了日粮粗脂肪消化率,其中以２４０ｍｇ／ｋｇ无机铜组最为显著,较对照组提高了３１．０％（Ｐ＜０．０５）,其次为５０ｍｇ／ｋｇ酪蛋白铜组,提高了２９．１％（Ｐ＜０．０５）,但是添加无机铜（硫酸铜）和蛋白铜对干物质和粗蛋白表观消化率均无明显影响。③添加铜对仔猪胴体组成无明显影响,但２４０ｍｇ／ｋｇ无机铜组和酪蛋白铜组肌肉失水率略有升高,色泽呈下降趋势。④２４０ｍｇ／ｋｇ无机铜组和５０ｍｇ／ｋｇ酪蛋白铜组的脑铜含量显著升高,分别较对照组提高了３３．１     

不同化学形式铜盐对仔猪生长性能和微量元素代谢的影响

选用１５０头杜长大三元杂交仔猪,分别饲喂含不同化学形式铜的饲粮,研究它们对仔猪生长性能、微量元素代谢等的影响,并评定不同化学形式铜盐的生物效价。试验结果表明：①饲粮中添加不同化学形式铜盐均影响了仔猪的生长,其中以５０ｍｇ／ｋｇ酪蛋白铜组生长最快,较对照组提高了１４．０％（Ｐ＜０．０５）,其次为２４０ｍｇ／ｋｇ硫酸铜,提高了１２．７％（Ｐ＜０．０５）;②添加２４０ｍｇ／ｋｇ硫酸铜和蛋白铜均可显著提高饲粮粗脂肪的消化率（Ｐ＜０．０５）;③饲粮中添加２４０ｍｇ／ｋｇ硫酸铜组和５０ｍｇ／ｋｇ酪蛋白铜组也显著提高了试验猪脑铜含量（Ｐ＜０．０５）,其中前者还使肝铜、胆汁铜、铁浓度明显上升（Ｐ＜０．０５）;④酪蛋白铜的生物效价显著高于常规使用的硫酸铜。     

硫辛酸对黄羽肉鸡生长性能、抗氧化能力和免疫功能的影响

本试验旨在研究饲粮中添加硫辛酸对黄羽肉鸡生长性能、抗氧化能力和免疫功能的影响。将 ６０只 ２１日龄体重相近的黄羽肉鸡随机分为 ２组,即对照组和硫辛酸组,每组 ５个重复,每个重复 ６只鸡。对照组饲喂基础饲粮,硫辛酸组饲喂在基础饲粮中添加 ３００ｍｇ／ｋｇ硫辛酸的试验饲粮,试验期 ３０ｄ。结果表明,硫辛酸对黄羽肉鸡的生长性能无显著影响（Ｐ＞０．０５）;在试验第 １５天时,硫辛酸可以显著提高黄羽肉鸡血清总超氧化物歧化酶活性（Ｐ＜０．０５）、降低一氧化氮含量（Ｐ＜０．０５）,促进脾脏的发育（Ｐ＜０．０５）,提高血清免疫球蛋白 Ｇ含量（Ｐ＜０．０１）;在试验第 ３０天时,硫辛酸可以显著降低黄羽肉鸡血清丙二醛含量（Ｐ＜０．０５）、提高抑制羟自由基的能力（Ｐ＜０．０１）,提高由伴刀豆球蛋白 Ａ和脂多糖刺激的外周血淋巴细胞转化率以及血清免疫球蛋白 Ｇ含量（Ｐ＜０．０５）。由本试验可知,饲粮中添加 ３００ｍｇ／ｋｇ硫辛酸可以在一定程度上提高肉鸡抗氧化能力,增强其免疫功能。     

二氢吡啶对蛋品质的影响及其机理研究

取３００ 日龄罗曼蛋鸡１ ５３６ 只，随机分为４ 组（ 每组设４ 个重复，每个重复９６ 只） ，在自由采食、饮水和光照１６ｈ 的条件下，分别饲喂添加０ｍｇ／ｋｇ 、１００ｍｇ／ｋｇ 、１５０ｍｇ／ｋｇ 、２００ｍｇ／ｋｇ二氢吡啶的玉米—豆粕型饲粮１３ 周。结果发现：①饲粮中含１００ｍｇ／ｋｇ 、１５０ｍｇ／ｋｇ 或２００ｍｇ／ｋｇ的二氢吡啶， 能使蛋壳厚度分别增加１１ ．３３ ％ （Ｐ＜ ０ ．０１） 、１６ ．８５％ （Ｐ＜ ０ ．００１） 和２０．１７ ％ （Ｐ＜ ０ ．００１） ；②饲粮中含１５０ｍｇ／ｋｇ 或２００ｍｇ／ｋｇ 的二氢吡啶，能使蛋比重和蛋壳相对重分别增加０ ．４４％ （Ｐ＜ ０ ．０５） 、０ ．５３ ％ （Ｐ＜ ０．０５） 和５ ．６６％ （Ｐ＜ ０ ．０５） 、６ ．９７ ％ （Ｐ＜ ０．０５） ，血清钙含量分别提高了１６．９０ ％ （Ｐ＜ ０ ．０５） 和１８ ．３３％ （Ｐ＜ ０．０５） ，而血清甲状旁腺素水平则分别下降了１８．０４ ％ （Ｐ＜ ０ ．０５） 和２０．００％ （Ｐ＜ ０ ．０５） 。     

不同锰源及锰水平对雏鸭肝脏脂肪沉积的影响

选用１日龄北京雏鸭３００只，研究不同锰源及其锰添加水平对雏鸭肝脏脂肪沉积和肝锰含量的影响。试验１随机分为７组，每组３０只试鸭，在基础饲粮中（含Ｍｎ１９ｍｇ／ｋｇ），钙源及锰添加水平依次为４５、８５、１３５ｍｇ／ｋｇ（试剂级ＭｎＳＯ＿４·Ｈ＿２Ｏ或ＭｎＣＯ＿３）。试验２随机分４组，每组３０只试鸭，在基础饲粮上（含Ｍｎ１９ｍｇ／ｋｇ），补锰水平依次为０、１１０、１０００、３５００ｍｇ／ｋｇ（试剂级ＭｎＳＯ＿４·Ｈ＿２Ｏ），试验３周。结果为：锰源不影响雏鸭肝脏脂肪沉积，肝锰含量和千克活体肝重（Ｐ＞０．０５），锰缺乏（含Ｍｎ１９ｍｇ／ｋｇ）或锰过量（补Ｍｎ３５００ｍｇ／ｋｇ）均影响雏鸭肝脏脂肪沉积和肝锰含量变化（Ｐ＜０．０５或Ｐ＜０．０１）。综合试验结果为：如以肝锰变化作为机体锰营养状况评定指标，则饲粮锰适宜添加量为８５～１３５ｍｇ／ｋｇ。     

饲粮不同维生素 Ｅ水平对鹅生产性能、胴体品质、血清生化指标和生殖激素含量的影响

本试验以 ０～１２周龄肝用型鹅为研究对象,通过探讨饲粮不同维生素 Ｅ水平对青农灰鹅生产性能、胴体品质、血清生化指标和生殖激素含量的影响,确定育雏、育成期鹅维生素 Ｅ的需要量。试验选择 １日龄青农灰鹅 １８０只,随机分为 ６个处理,每个处理 ３个重复,每个重复 １０只。试验鹅饲喂在玉米 －豆粕型饲粮的基础上分别添加 ０（对照组）、５、１０、２０、４０、８０ＩＵ／ｋｇ维生素 Ｅ的饲粮,试验期为 １２周。结果表明：１）与对照组相比,饲粮添加 ４０、８０ＩＵ／ｋｇ维生素 Ｅ可显著提高 ０～４周龄鹅平均日增重和平均日采食量（Ｐ＜０．０５）,饲粮添加 ４０ＩＵ／ｋｇ维生素 Ｅ可显著提高 ５～１２周龄鹅平均日增重和平均日采食量（Ｐ＜０．０５）。２）饲粮添加 ４０、８０ＩＵ／ｋｇ维生素 Ｅ可显著降低 １２周龄鹅胸肌剪切力和失水率（Ｐ＜０．０５）,饲粮添加 ８０ＩＵ／ｋｇ维生素 Ｅ可显著提高 １２周龄鹅半净膛率和胸肌率（Ｐ＜０．０５）。３）提高饲粮维生素 Ｅ水平可显著提高 ４周龄鹅血清尿素氮含量（Ｐ＜０．０５）,显著降低１２周龄鹅血清尿素氮含量（Ｐ＜０．０１）,饲粮添加４０ＩＵ／ｋｇ维生素 Ｅ可显著提高 ４周龄和 １２周龄鹅血清碱性磷酸酶活性（Ｐ＜０．０５）。４）与对照组相比,４０、８０ＩＵ／ｋｇ维生素 Ｅ组１２周龄母鹅血清中雌二醇含量显著升高（Ｐ＜０．０５）,促卵泡素含量显著降低（Ｐ＜０．０５）。２０、４０、８０ＩＵ／ｋｇ维生素 Ｅ组 １２周龄公鹅血清中雌二醇、睾酮含量均显著升高（Ｐ＜０．０５）,促卵泡素含量显著降低（Ｐ＜０．０５）。本研究结论如下：１）维生素 Ｅ对鹅的生产性能、胴体品质、血清中尿酸、尿素氮、生殖激素含量和碱性磷酸酶活性具有一定调控作用;２）根据建立的回归方程确定肝用型鹅饲粮维生素 Ｅ最适添加量为：０～４周龄４２．９８ＩＵ／ｋｇ,５～１２周龄 ３８．９２～４３．４１ＩＵ／ｋｇ;３）根据鹅血清中生殖激素含量的变化确定饲粮维生素 Ｅ最低添加量为２０ＩＵ／ｋｇ。     

日粮中添加高剂量铜对肉用仔鸡生长和肝、粪铜浓度的影响

用１６４只１周龄ＡＡ肉用仔鸡进行的两次试验结果显示，在含铜８—１４ｍｇ／ｋｇ的玉米—豆饼日粮中，添加１２５ｍｇ／ｋｇ铜（ＣｕＳＯ４５Ｈ２Ｏ），提高４—７周龄平均增重７．１－１０．８％（Ｐ＜０．０５或０．０１），提高１—３周龄平均增重２．１－２．５％（Ｐ＞０．０５，试验Ⅱ）或６．２％（Ｐ＜０．０１，试验Ⅰ），降低１—３周龄饲料／增重６．３－１５．３％，添加１２５ｍｇ／ｋｇ铜，对胸肌含水量无影响（Ｐ＞０．０５），明显提高了肝铜含量（Ｐ＜０．０５），但幅度不太大，由对照组的１３．８ｍｇ／ｋｇ提高到２３．８ｍｇ／ｋｇ（风干基础），而正常鸡肝含铜量低，因此对食品卫生无不利影响。大量铜由粪中排出体外，试验组粪铜浓度比对照组提高９倍。     

日粮苯丙氨酸水平对0～4周龄泰和乌鸡生产性能及组织黑色素含量的影响

为研究日粮苯丙氨酸水平对泰和乌鸡生产性能和组织黑色素含量的影响。选用1日龄泰和乌鸡108只,随机分成3组,每组设3个重复,每个重复12只鸡(公母各半),饲养至4周龄。试验鸡组分别饲喂3种苯丙氨酸水平的日粮,日粮苯丙氨酸水平分别为0.73%、1.00%和1.27%。结果表明:日粮苯丙氨酸水平显著影响0~4周龄泰和乌鸡平均日增重(P<0.01),其中1.27%组日增重极显著高于0.73%组(P<0.01),显著高于1.00%组(P<0.05);1.00%组显著高于0.73%组(P<0.05)。但日粮苯丙氨酸水平对泰和乌鸡的饲料转化效率(料重比)和平均日采食量无显著影响(P>0.05)。胸肌黑色素含量随着日粮苯丙氨酸水平的提高而降低,1.27%组胸肌黑色素含量极显著低于0.73%和1.00%组(P<0.01),但0.73%和1.00%两组之间无显著差异(P>0.05)。尽管腿肌和皮肤黑色素含量在各组之间不存在显著差异(P>0.05),但黑色素含量有随日粮苯丙氨酸水平提高而增大的趋势。     

日粮酪氨酸、苯丙氨酸、色氨酸水平和比例对泰和乌骨鸡生产性能及组织黑色素含量的影响

本试验旨在研究日粮酪氨酸、苯丙氨酸和色氨酸供给水平和比例对泰和乌骨鸡生产性能和组织黑色素含量的影响.选用612只1日龄泰和乌骨鸡,随机分成17个处理,每个处理设3个重复,每个重复12只鸡(公母各占1/2),饲养至4周龄.采用三因素二次回归正交组合设计试验方法,建立日粮三种氨基酸水平与泰和乌骨鸡日增重和组织黑色素含量的二次回归数学模型,得出0～4周龄泰和乌骨鸡分别取得最大日增重和组织黑色素含量时日粮三种氨基酸适宜供给量和比例模式.结果表明,日粮酪氨酸,苯丙氨酸和色氨酸供给水平和比例显著影响泰和乌骨鸡日增重和胸肌、腿肌黑色素含量(P<0.01),且泰和乌骨鸡取得最大日增重和组织黑色素含量时日粮三种氨基酸最适水平和比例模式各不相同.当日粮氨基酸含量分别为酪氨酸0.79%、苯丙氨酸1.06%和色氨酸0.13%,三者比例模式为Tyr:Phe:Trp=85:113:14(相对于日粮Lys含量的比值,Lys定为100)时,可取得最大日增重5.81 g/d;而当日粮三种氨基酸含量分别为酪氨酸0.81%、苯丙氨酸1.14%和色氨酸0.13%时,胸肌黑色素含量可取得最大值3.73%,三者最佳比例模式为Tyr:Phe:Trp=87:121:14.因此,通过调节日粮酪氨酸、苯丙氨酸和色氨酸供给水平和比例可改善泰和乌骨鸡生产性能以及体内黑色素的沉积.     

生长前期丝羽乌骨鸡饲粮适宜能量、蛋白水平研究

两因子设计 ,以1日龄丝羽乌骨鸡504只为材料 ,进行饲养试验结合代谢试验考察了饲粮代谢能(ME)、粗蛋白质(CP)对生长前期(0～8周)丝羽乌骨鸡生产性能的影响规律。结果表明 ,通过饲粮营养调控可显著改善生长前期丝羽乌骨鸡的生长速度和生产性能 ,ME显著(P<0.05)或极显著(P<0.01)影响各阶段平均日采食量(ADFI)和饲料转化率(FCR) ,CP显著影响3周龄前的生产性能指标(P<0.05) ,二者互作影响不显著(P>0.05) ;增加营养素摄入量有利于改善丝羽乌骨鸡对营养素的表观利用率。推荐3周龄前饲粮ME为13.40MJ/kg、CP为20 % ,整个生长前期(0～8周)推荐使用ME为12.35MJ/kg、CP为18 %饲粮以获得较好生产成绩和经济效益     

The Effect of Dietary Sulphate Copper Supplementation on Growth Performance, Intestinal Digestive Enzymes and Absorptive Transporters in Weanling Pigs

The experiment was conducted to assess the effects of dietary supplementation of Cu on the growth performance,digestive enzymes,tissue minerals and absorptive transporters in small intestinal mucosa of weanling pigs.One hundred crossbred pigs weaned at 28±2 d of age were assigned randomly to one of the following diets with 5 replicates:corn-soybean basal diet with 10,100,175,250 mg/kg of Cu as CuSO4·5H2O.The results showed that 250 mg/kg Cu had a positive effect (P0.05) on average daily gain,daily feed intake and ratio of gain/feed.Compared to 10 mg/kg Cu,higher Cu had significant effect on the apparent digestibility of protein and fat (P0.05).The supplementing of Cu improved amylase and lipase activity in jejunum content and lipase in pancreas (P0.05) and had no effect on intestinal morphology.The liver Cu elevated approximately 4-fold in pigs fed diet with 250 mg/kg Cu compared with pigs fed diet with 10 mg/kg Cu,no increases were observed in pigs receiving the lower level of Cu (100 and 175 mg/kg).Both Fe and Zn contents in kidney and liver were not affected by Cu supplementation.There was no positive effect (P0.05) of Cu supplementation on PepT1 (peptide transporter 1) and SGLT1 (sodium/glucose cotransporter) mRNA abundance in intestinal mucosa.However,higher supplementing level (250 mg/kg) significantly elevated the DMT1 (divalent metal transporter) mRNA abundance in duodenum mucosa.These results suggested that dietary supplementation with 250 mg/kg Cu could improve growth performance,nutrient digestibility and intestinal enzyme activities of weanling pigs.     

Growth response, blood characteristics and copper accumulation in organs of broilers fed on diets supplemented with organic and inorganic dietary copper sources

1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.     

Effects of dietary copper on the expression of lipogenic genes and metabolic hormones in steers

An experiment was conducted to determine the effects of Cu supplementation on performance, subcutaneous adipose tissue mRNA expression of acetyl CoA carboxylase (ACC), stearoyl CoA desaturase (SCD), uncoupling protein 2 (UCP2), and leptin in growing and finishing steers. Forty-eight purebred Angus steers were allotted to one of five treatments: 1) control (no supplemental Cu); 2) 10 mg Cu/kg DM from CuSO4; 3) 10 mg Cu/kg DM from a Cu amino acid complex (Availa Cu); 4) 20 mg Cu/kg DM from CuSO4; 5) 20 mg Cu/kg DM from Availa Cu. Steers were fed an alfalfa hay corn-based diet for 56 d (basal diet contained 7.1 mg Cu/kg DM) and switched to a high-concentrate diet for 144 d (basal diet contained 6.1 mg Cu/kg DM). Blood samples were obtained every 28 d throughout the entire experiment. On d 112 of the finishing period, subcutaneous adipose tissue biopsies were obtained from the tailhead of three animals per treatment and analyzed for ACC, SCD, UCP2, and leptin mRNA expression. Animal performance was not affected by Cu supplementation during the growing phase. Steers receiving 10 mg Cu/kg DM from Availa Cu had higher (P < 0.05) ending body weights and tended (P < 0.10) to have higher ADG than steers receiving 10 mg Cu/kg DM from CuSO4 during the finishing phase. Serum concentrations of nonesterified fatty acid and insulin were not affected by Cu supplementation. Steers receiving supplemental Cu tended (P < 0.11) to have less backfat relative to controls. However, dietary Cu did not influence the level of subcutaneous adipose tissue ACC and SCD mRNA. Neither UCP2 nor leptin gene expression was affected by Cu supplementation. These results indicate that dietary Cu supplementation (10 to 20 mg Cu/kg DM diet) may alter lipid metabolism of subcutaneous adipose tissue; however, it does not seem to affect expression of certain lipogenic genes.     

1～21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量的研究

本试验旨在研究饲粮不同硒添加水平对1~21日龄岭南黄羽肉仔鸡生长性能和抗氧化性能的影响,以探讨快大型岭南黄羽肉仔鸡饲养前期的饲粮硒适宜供给量。选用1日龄健康、发育良好的快大型岭南黄羽肉公雏鸡1 200只,根据体重随机分为5个组,每组6个重复,每个重复40只鸡,试验1组(对照组)饲喂基础饲粮(硒水平为0.039 mg/kg),试验2~5组饲粮在基础饲粮中分别添加0.075、0.150、0.225和0.300 mg/kg硒,试验期21 d。结果表明:本试验条件下:1)与对照组相比,饲粮添加0.300 mg/kg硒显著降低1~21日龄岭南黄羽肉仔鸡的末重(P0.05),显著提高料重比(P0.05),且0.300 mg/kg硒添加组的平均日增重显著低于其他各水平硒添加组(P0.05)。2)与对照组相比,饲粮添加0.075和0.150 mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的血浆谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),饲粮添加0.225和0.300 mg/kg硒显著降低血浆丙二醛(MDA)含量(P0.05)。各水平硒添加组的红细胞GSH-Px活性均显著高于对照组(P0.05)。3)与对照组相比,饲粮添加0.075、0.150和0.225mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的肝脏GSH-Px活性(P0.05),0.075和0.150 mg/kg硒添加组的肝脏MDA含量显著低于对照组和0.300 mg/kg硒添加组(P0.05)。综合考虑,为获得较好生长性能和抗氧化性能,1~21日龄岭南黄羽肉仔鸡饲粮硒适宜添加水平为0.075 mg/kg,基础饲粮中硒水平为0.039 mg/kg,则1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.114 mg/kg;以肝脏MDA含量为依据,通过非线性回归分析估测得到1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.130 mg/kg。     

L-组氨酸对肉鸡生长性能、肌肉品质、血浆抗氧化能力和肌肉咪唑二肽含量的影响

本试验旨在研究饲粮添加L-组氨酸对肉鸡生长性能、肌肉品质、血浆抗氧化能力和肌肉咪唑二肽含量的影响。选取体重相近、健康的1日龄爱拔益加(AA)肉仔鸡公雏300只,随机分为5组,每组6个重复,每个重复10只鸡。对照组饲喂基础饲粮,试验组饲喂在基础饲粮中分别添加250、500、1 000、2 000 mg/kg L-组氨酸的试验饲粮。试验期42 d。结果表明:1)L-组氨酸降低了肉鸡生长后期(22~42日龄)的料重比,250和2 000 mg/kg添加组显著低于对照组(P0.05)。2)L-组氨酸对肌肉全净膛率、胸肌率、腿肌率、腹脂率、滴水损失、剪切力和pH无显著影响(P0.05)。3)L-组氨酸线性提高了42日龄血浆总抗氧化能力及谷胱甘肽过氧化物酶、总超氧化物歧化酶的活性(P0.05)。4)L-组氨酸增加了42日龄肌肉中肌肽和鹅肌肽含量,500、1 000和2 000 mg/kg添加组肌肽含量分别较对照组升高了40.58%、42.75%、33.70%(P0.05),1 000 mg/kg添加组鹅肌肽含量较对照组增加了37.80%(P0.05);对肌肉中肌肽和鹅肌肽含量进行二次曲线方程拟合表明,L-组氨酸添加量为1 276 mg/kg时,肌肉咪唑二肽含量最高。可见,饲粮添加L-组氨酸可提高肉鸡的饲料转化率,改善血浆抗氧化能力,增加肌肉中咪唑二肽含量。本试验条件下,饲粮添加1 000~2 000 mg/kg L-组氨酸较佳。从增加肌肉咪唑二肽含量考虑,饲粮L-组氨酸适宜添加量为1 276 mg/kg     

The Effect of Dietary Sulphate Copper Supplementation on Growth Performance, Intestinal Digestive Enzymes and Absorptive Transporters in Weanling Pigs

The experiment was conducted to assess the effects of dietary supplementation of Cu on the growth performance, digestive enzymes, tissue minerals and absorptive transporters in small intestinal mucosa of weanling pigs. One hundred crossbred pigs weaned at 28 ± 2 d of age were assigned randomly to one of the following diets with 5 replicates: corn-soybean basal diet with 10, 100, 175, 250 mg/kg of Cu as CuSO₄•5H₂O. The results showed that 250 mg/kg Cu had a positive effect (P < 0.05) on average daily gain, daily feed intake and ratio of gain/feed. Compared to 10 mg/kg Cu, higher Cu had significant effect on the apparent digestibility of protein and fat (P < 0.05). The supplementing of Cu improved amylase and lipase activity in jejunum content and lipase in pancreas (P < 0.05) and had no effect on intestinal morphology. The liver Cu elevated approximately 4-fold in pigs fed diet with 250 mg/kg Cu compared with pigs fed diet with 10 mg/kg Cu, no increases were observed in pigs receiving the lower level of Cu (100 and 175 mg/kg). Both Fe and Zn contents in kidney and liver were not affected by Cu supplementation. There was no positive effect (P > 0.05) of Cu supplementation on PepT1 (peptide transporter 1) and SGLT1 (sodium/glucose cotransporter) mRNA abundance in intestinal mucosa. However, higher supplementing level (250 mg/kg) significantly elevated the DMT1 (divalent metal transporter) mRNA abundance in duodenum mucosa. These results suggested that dietary supplementation with 250 mg/kg Cu could improve growth performance, nutrient digestibility and intestinal enzyme activities of weanling pigs.     

Dietary copper effects on lipid metabolism, performance, and ruminal fermentation in finishing steers

Sixty Angus steers (391.1+/-6.1 kg) were used to determine the effects of dietary Cu concentration on lipid metabolism and ruminal fermentation. Steers were stratified by weight and randomly assigned to treatments. Treatments consisted of 0 (control), 10, or 20 mg of supplemental Cu (as CuSO4)/kg diet DM. Steers were housed in pens equipped with individual electronic Calan gate feeders. On d 86 and 92, ruminal fluid was collected from two steers/treatment for IVDMD determination. Equal numbers of steers per treatment were slaughtered after receiving the finishing diets for 96 or 112 d. Gain, feed intake, feed efficiency, IVDMD, and ruminal VFA molar proportions were not affected by Cu supplementation. Copper supplementation increased (P < .05) liver Cu concentrations, and steers supplemented with 20 mg Cu/kg DM had higher (P < .05) liver Cu concentrations than steers supplemented with 10 mg Cu/kg DM. Serum total cholesterol concentrations were reduced by d 56 and at subsequent sampling dates in steers receiving supplemental Cu. Longissimus muscle cholesterol concentrations were lower (P < .10) in steers supplemented with Cu. Backfat depth was less (P < .05) in steers receiving supplemental Cu, but marbling scores were similar across treatments. Unsaturated fatty acid composition of longissimus muscle was increased (P < .05) and saturated fatty acid composition tended (P < .12) to be reduced in Cu-supplemented steers. Polyunsaturated fatty acid concentrations were higher (P < .05) in steers receiving Cu. These results indicate that addition of 10 or 20 mg Cu/kg to a high-concentrate diet containing 4.9 mg Cu/kg DM alters lipid and cholesterol metabolism in steers but does not affect ruminal fermentation.