李三軍 李俊營(yíng) 戚仁榮 馬瑞鈺 劉偉 萬(wàn)意 詹凱
摘 要:本試驗(yàn)旨在探究夏秋茶綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞產(chǎn)蛋性能、屠宰性能和血液生化指標(biāo)的影響。將健康狀況良好、體重相近的108只62周齡皖南三黃雞母雞隨機(jī)分為對(duì)照組(GTP 0)、GTP 0.5組、GTP 1.0組和GTP 1.5組,每組3個(gè)重復(fù),每個(gè)重復(fù)9只。對(duì)照組飼喂玉米-豆粕型基礎(chǔ)日糧,GTP 0.5組、GTP 1.0組和GTP 1.5組分別飼喂含0.5%、1.0%和1.5%綠茶粉的基礎(chǔ)日糧。試驗(yàn)期8周。結(jié)果顯示:與對(duì)照組相比,試驗(yàn)組產(chǎn)蛋率顯著降低(P<0.05);GTP 1.0組平均蛋重顯著高于對(duì)照組(P<0.05),GTP 0.5組和GTP 1.5組平均蛋重和日采食量均低于對(duì)照組,而料蛋比則高于對(duì)照組(P<0.05);試驗(yàn)組腹脂率隨著GTP添加量增加呈降低趨勢(shì),其中GTP 1.5組腹脂率顯著低于對(duì)照組(P<0.05);GTP 0.5組血液總膽固醇(T-CH)含量顯著低于對(duì)照組(P<0.05);GTP 0.5組血液丙二醛(MDA)含量顯著低于對(duì)照組(P<0.05),而超氧化物歧化酶(SOD)和谷胱甘肽過氧化物酶(GSH-Px)含量則顯著高于對(duì)照組(P<0.05)。綜上所述,在本試驗(yàn)條件下,添加綠茶粉可以改善產(chǎn)蛋后期皖南三黃雞的血液生化指標(biāo)和降低腹脂率,但同時(shí)也降低了產(chǎn)蛋性能。
關(guān)鍵詞:皖南三黃雞;綠茶粉;產(chǎn)蛋性能;屠宰性能;生化指標(biāo)
中圖分類號(hào):S816.7文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1673-1085(2024)05-0007-07
基金項(xiàng)目:現(xiàn)代農(nóng)業(yè)產(chǎn)業(yè)技術(shù)體系建設(shè)專項(xiàng)基金(項(xiàng)目編號(hào):CARS-40-K21;CARS-40-S10);安徽省肉雞良種聯(lián)合攻關(guān)項(xiàng)目;安徽省重點(diǎn)研究與開發(fā)計(jì)劃項(xiàng)目(項(xiàng)目編號(hào):202204c06020054)
第一作者:李三軍(1996—),男,碩士,科研助理,主要從事家禽遺傳育種與生產(chǎn)研究,E-mail: lisanjun202311@163.com
*通信作者:詹凱(1968—),男,博士,研究員,主要從事家禽遺傳育種與生產(chǎn)研究,E-mail: zhankai633@126.com
我國(guó)夏秋茶資源豐富,但是因其酚氨比值高,口感苦澀,導(dǎo)致價(jià)格低廉、采摘率低,從而造成資源的浪費(fèi)[1]。研究表明,茶葉中含有的生物活性物質(zhì)具有抗炎、抑菌、抗病毒、抗氧化、調(diào)節(jié)脂質(zhì)代謝和提高免疫力等生物學(xué)功能,可以作為一種植物源飼料或者添加劑應(yīng)用到畜禽生產(chǎn)中[2, 3]。綠茶作為未發(fā)酵茶是這些活性物質(zhì)的最佳來源[4]。皖南三黃雞是安徽省優(yōu)良的兼用型土雞品種,但在產(chǎn)蛋后期,其機(jī)體健康狀況亟待改善。在飼料禁抗和畜禽綠色養(yǎng)殖的趨勢(shì)下,開展夏秋茶綠茶粉的飼用化研究具有重要意義。本試驗(yàn)以產(chǎn)蛋后期皖南三黃雞為研究對(duì)象,探索了日糧中添加夏秋茶綠茶粉對(duì)皖南三黃雞產(chǎn)蛋性能、屠宰性能和血液生化指標(biāo)的影響,為夏秋茶的開發(fā)利用和皖南三黃雞的健康養(yǎng)殖提供參考。
1? 材料與方法
1.1? 試驗(yàn)動(dòng)物與飼養(yǎng)管理
選取62周齡健康狀況良好的皖南三黃雞母雞108只,隨機(jī)分為4組,每組3個(gè)重復(fù),每個(gè)重復(fù)9只雞。各組之間初始體重和產(chǎn)蛋率差異不顯著。對(duì)照組飼喂玉米-豆粕型基礎(chǔ)日糧,GTP 0.5組、GTP 1.0組和GTP 1.5組分別飼喂含0.5%、1.0%和1.5%綠茶粉的基礎(chǔ)日糧。預(yù)試期1周,正試期8周。
試驗(yàn)雞采用階梯式籠養(yǎng)。整個(gè)試驗(yàn)期內(nèi)自由采食和飲水,光照時(shí)間16 h/d,光照強(qiáng)度10 lx,每天8:00和15:30人工飼喂粉料?;A(chǔ)日糧組成及營(yíng)養(yǎng)水平見表1。綠茶粉(綠茶末粉碎,過1 mm標(biāo)準(zhǔn)分析篩所得)由安徽寧清茶業(yè)有限公司提供,其中干物質(zhì)95.34%、粗纖維2.77%、粗蛋白質(zhì)18.32%、粗灰分4.01%、粗脂肪12.39%、鈣0.26%、磷0.22%,茶多酚12.64%、游離氨基酸3.70%。
1.2? 測(cè)定指標(biāo)及方法
1.2.1? 生產(chǎn)性能? 試驗(yàn)期間,每天15:00統(tǒng)計(jì)各重復(fù)采食量、產(chǎn)蛋數(shù)和產(chǎn)蛋總重。計(jì)算各組雞只的產(chǎn)蛋率、日采食量、平均蛋重和料蛋比。
1.2.2? 屠宰性能? 試驗(yàn)結(jié)束,雞群空腹12 h后,每個(gè)重復(fù)隨機(jī)選取3只雞,稱重,頸動(dòng)脈放血后濕拔法去除羽毛、腳角質(zhì)層、趾殼和喙殼,再稱量屠體重。分離頭、腳和內(nèi)臟器官,剝離胸肌、腿肌和腹脂,稱量并記錄腿肌重量、胸肌重量和腹脂重量,測(cè)定方法參照《家禽生產(chǎn)性能名詞術(shù)語(yǔ)和度量計(jì)算方法》(NY/T823-2020)。
1.2.3? 血液生化指標(biāo)? 試驗(yàn)結(jié)束,雞群禁食12 h后,每個(gè)重復(fù)隨機(jī)選取4只雞,使用含EDTA抗凝劑的采血管于翅下靜脈采血2 mL,搖勻放入冰盒中帶回實(shí)驗(yàn)室,使用低速離心機(jī)分離血漿,按照試劑盒說明進(jìn)行測(cè)定(試劑盒購(gòu)自合肥瑞恩生物科技有限公司),測(cè)定指標(biāo)包括葡萄糖(GLU)、總膽固醇(T-CH)、甘油三酯(TG)、低密度脂蛋白(LDL)和高密度脂蛋白(HDL)及丙二醛(MDA)、超氧化物歧化酶(SOD)和谷胱甘肽過氧化物酶(GSH-Px)。
1.3? 數(shù)據(jù)統(tǒng)計(jì)與分析
試驗(yàn)數(shù)據(jù)先用Excel 2016進(jìn)行初步處理,進(jìn)一步利用SPSS(27.0.1)進(jìn)行單因素方差分析,并采用Tukey檢驗(yàn)法比較平均值間的差異顯著性。最終結(jié)果用“平均值±標(biāo)準(zhǔn)差”表示,以P<0.05表示差異顯著。
2? 結(jié)果與分析
2.1? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞產(chǎn)蛋性能的影響
表2為綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞產(chǎn)蛋性能的影響。由表2可知,與對(duì)照組相比,試驗(yàn)組產(chǎn)蛋率顯著降低(P<0.05);GTP 1.0組平均蛋重顯著升高(P<0.05);與對(duì)照組相比,GTP 0.5組和GTP 1.5組料蛋比顯著升高,而日采食量顯著降低(P<0.05)。
2.2? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞屠宰性能的影響
表3為綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞屠宰性能的影響。由表3可知,各組之間宰前體重、屠宰率、半凈膛率、全凈膛率、胸肌率和腿肌率均無顯著差異(P>0.05)。但是,GTP 1.5組腹脂率顯著低于對(duì)照組(P<0.05)。
2.3? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞血液生化指標(biāo)的影響
表4為綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞血液生化指標(biāo)的影響。由表4可知,各組血漿中GLU、TG、LDL和HDL含量之間均無顯著差異(P>0.05)。GTP 0.5組T-CH含量顯著低于對(duì)照組(P<0.05)。
與對(duì)照組相比,GTP 0.5組血漿MDA含量顯著降低(P<0.05),GTP 1.0組和GTP 1.5組MDA含量顯著升高(P<0.05)。GTP 0.5和GTP 1.5組血漿SOD含量顯著高于對(duì)照組(P<0.05)。綠茶粉組血漿GSH-Px含量均顯著高于對(duì)照組(P<0.05)。
3? 討論
3.1? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞產(chǎn)蛋性能影響
據(jù)Al-Harthi[5]報(bào)道,日糧添加綠茶粉對(duì)蛋雞的產(chǎn)蛋性能有改善作用,0.1%綠茶粉可以提高平均蛋重、產(chǎn)蛋率和飼料轉(zhuǎn)化率,并降低采食量。Rizk等[6]同樣發(fā)現(xiàn),0.1%綠茶粉提高了蛋雞的產(chǎn)蛋性能,但是當(dāng)綠茶粉添加量為0.2%時(shí)產(chǎn)蛋性能顯著降低。然而Li等[7]在京粉蛋雞的試驗(yàn)結(jié)果表明,綠茶粉添加量在0.5%和0.75%時(shí)均能提高產(chǎn)蛋率和飼料轉(zhuǎn)化率,當(dāng)添加量達(dá)到1.0%時(shí)會(huì)對(duì)產(chǎn)蛋率有一定的降低作用,但是未達(dá)到顯著效果。Chen等[8]研究結(jié)果也表明,1.0%綠茶粉不會(huì)顯著影響蛋雞產(chǎn)蛋性能。Xia等[9]以1.0%、2.0%和3.0%綠茶粉飼喂仙居雞時(shí)同樣發(fā)現(xiàn),1.0%綠茶粉對(duì)蛋雞產(chǎn)蛋性能無顯著影響,而2%和3%綠茶粉則顯著降低了蛋雞的產(chǎn)蛋率、平均蛋重、采食量和飼料轉(zhuǎn)化率。此外,Ariana等[10]研究表明,1.5%綠茶粉對(duì)產(chǎn)蛋后期海蘭白蛋雞的產(chǎn)蛋性能有降低作用,但是效果也不顯著。本試驗(yàn)中同樣發(fā)現(xiàn)了綠茶粉降低蛋雞采食量的現(xiàn)象,與上述結(jié)果不同的是,產(chǎn)蛋率等產(chǎn)蛋性能在0.5%~1.5%綠茶粉添加量下均表現(xiàn)出降低或顯著降低,這可能與綠茶粉有效活性物質(zhì)的含量及蛋雞的品種、日齡和飼養(yǎng)管理方式等多種因素有關(guān)。一般而言,綠茶粉中含有的茶多酚可通過發(fā)揮抗炎、抗氧化、調(diào)節(jié)脂質(zhì)代謝等作用來調(diào)節(jié)機(jī)體健康,改善蛋雞產(chǎn)蛋性能[2]。然而,茶多酚具有苦澀味,影響飼料的適口性,可能導(dǎo)致蛋雞采食量下降,造成能量和養(yǎng)分?jǐn)z入不足。此外,綠茶粉含有的單寧酸等一些酚酸具有抗?fàn)I養(yǎng)作用,可能會(huì)干擾機(jī)體對(duì)蛋白質(zhì)等營(yíng)養(yǎng)物質(zhì)的利用,從而降低蛋雞的產(chǎn)蛋性能[11]。
3.2? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞屠宰性能影響
屠宰性能是反映畜禽胴體品質(zhì)及經(jīng)濟(jì)效益的重要指標(biāo)之一[2]。據(jù)Xue等[12]報(bào)道,表沒食子兒茶素沒食子酸酯(EGCG)可以減輕熱應(yīng)激狀態(tài)下肉雞的氧化損傷,改善其生長(zhǎng)性能。Erener等[13]也發(fā)現(xiàn),綠茶提取物可以顯著提高肉仔雞的胴體重和屠宰率。與此相反,Aziz-Aliabadi等[14]以1.0%和2.0%綠茶粉飼喂Ross 308肉仔雞40 d,發(fā)現(xiàn)屠宰性能各項(xiàng)指標(biāo)未發(fā)生顯著變化。Hrnar等[15]研究發(fā)現(xiàn),添加0.5%~1.5%綠茶粉對(duì)42日齡Ross 308肉仔雞的屠宰率、胸肌率和腿肌率等無顯著影響,但是與對(duì)照組相比,綠茶粉組肉雞的腹脂率降低,且1.5%綠茶粉組顯著降低,這與本試驗(yàn)結(jié)果一致。研究表明,綠茶粉中的茶多酚尤其是EGCG可以通過抑制前脂肪細(xì)胞增殖分化、降低消化道對(duì)營(yíng)養(yǎng)物質(zhì)的吸收和激活蛋白激酶磷酸化調(diào)節(jié)肝臟脂質(zhì)代謝等多種途徑降低腹脂沉積[16]。此外,本試驗(yàn)中綠茶粉組胸肌率和腿肌率均略高于對(duì)照組,這可能是由于綠茶粉中含有的咖啡堿刺激蛋雞神經(jīng)系統(tǒng)興奮,導(dǎo)致運(yùn)動(dòng)能力增強(qiáng),從而促進(jìn)肌肉衛(wèi)星細(xì)胞增殖分化,提高肌肉的生長(zhǎng)能力。
3.3? 綠茶粉對(duì)產(chǎn)蛋后期皖南三黃雞血液生化指標(biāo)的影響
血液中較高的GLU、T-CH、TG和LDL含量可能導(dǎo)致人和動(dòng)物脂肪肝、糖尿病和動(dòng)脈粥樣硬化等風(fēng)險(xiǎn)升高[17]。綠茶粉可以通過抑制腸道上皮黏膜細(xì)胞的葡萄糖轉(zhuǎn)運(yùn)、降低腸道對(duì)脂質(zhì)的吸收和影響肝臟LPL脂蛋白脂肪酶表達(dá)等方式降低人和動(dòng)物的血糖和血脂水平[8, 18]。據(jù)Chen等[8]報(bào)道,1.0%綠茶粉顯著降低了20周齡淮南麻黃雞血漿T-CH、TG和LDL含量,增加了HDL含量。Li等[7]以0.5%~1.0%綠茶粉飼喂24周齡京粉蛋雞發(fā)現(xiàn),添加綠茶粉降低或顯著降低了血漿TG和LDL含量,增加了HDL含量,但是對(duì)GLU含量無影響。而Ariana等[10]稱,1.5%綠茶粉顯著降低了64周齡海蘭白蛋雞血清T-CH含量,但是對(duì)GLU、TG、HDL和LDL含量無顯著影響。本試驗(yàn)結(jié)果與上述研究成果相近,同樣發(fā)現(xiàn)了綠茶粉具有降低血液中T-CH和TG濃度及升高HDL濃度的作用,但是對(duì)于T-CH外其余指標(biāo)作用不顯著,這可能是由于綠茶粉的活性物質(zhì)對(duì)糖脂代謝的影響與試驗(yàn)雞只的品種和日齡等因素有關(guān),受其生理營(yíng)養(yǎng)代謝差異影響。
氧化應(yīng)激是動(dòng)物體內(nèi)產(chǎn)生過多的活性氧打破機(jī)體氧化還原平衡造成的,MDA是膜脂發(fā)生過氧化反應(yīng)的終末代謝產(chǎn)物,具有細(xì)胞毒性,通過檢測(cè)血液中MDA含量可以判斷機(jī)體膜脂過氧化損傷程度,內(nèi)源性抗氧化劑SOD和GSH-Px因能夠有效抑制和清除活性氧而常用于評(píng)價(jià)機(jī)體的抗氧化能力[19]。茶多酚是一種典型的黃酮類天然抗氧化劑,通過間接調(diào)節(jié)轉(zhuǎn)錄因子及其下游氧化還原平衡系統(tǒng)相關(guān)酶的活性而發(fā)揮抗氧化作用[20]。綠茶作為提取茶多酚的主要原料同樣表現(xiàn)出較強(qiáng)的抗氧化能力[21]。據(jù)Rizk等[6]報(bào)道,日糧添加綠茶粉顯著提高了產(chǎn)蛋后期蛋雞的血液SOD和GSH-Px含量,降低了MDA含量。Wang等[22]發(fā)現(xiàn),165 mg/kg綠茶多酚EGCG可以提高蛋雞血漿SOD和GSH-Px含量,顯著降低MDA含量。在本試驗(yàn)中同樣發(fā)現(xiàn),綠茶粉對(duì)提高蛋雞血液抗氧化能力有一定作用,且添加比例為0.5%時(shí)效果最好。
4? 結(jié)論
在本試驗(yàn)條件下,日糧中添加0.5%綠茶粉可改善產(chǎn)蛋后期皖南三黃雞血液糖脂代謝和抗氧化性能,而添加1.5%綠茶粉可顯著降低腹脂含量,但均降低了產(chǎn)蛋性能。因此,在生產(chǎn)中應(yīng)按照實(shí)際需求,根據(jù)雞群和綠茶粉成分的差異嚴(yán)格控制好添加量。
參考文獻(xiàn):
[1]? JIA X, YAYUAN Z, MENGKE Z, et al. Effects of foliar selenium application on Se accumulation, elements uptake, nutrition quality, sensory quality and antioxidant response in summer-autumn tea[J]. Food research international, 2024, 175: 113618.
[2]? SEIDAVI A, BELALI M, ELGHANDOUR M M Y, et al. Potential impacts of dietary inclusion of green tea (Camellia sinensis L.) in poultry feeding: a review [J]. Agroforestry systems, 2020, 94(4): 1161-1170.
[3]? ABD EL-HACK M E, ELNESR S S, ALAGAWANY M, et al. Impact of green tea (Camellia sinensis) and epigallocatechin gallate on poultry[J]. World's poultry science journal, 2020, 76(1): 49-63.
[4]? MOHD F. Green tea catechins: natures way of preventing and treating cancer[J]. International journal of molecular sciences, 2022, 23(18): 10713.
[5]? AL-HARTHI M A. The effect of natural and synthetic antioxidants on performance, egg quality and blood constituents of laying hens grown under high ambient temperature[J]. Italian journal of animal science, 2014, 13(2): 3239.
[6]? RIZK Y S, ISMAIL I I, HAFSA S H A, et al. Effect of dietary green tea and dried seaweed on productive and physiological performance of laying hens during late phase of production[J]. Egyptian poultry science journal, 2017, 37(3): 685-706.
[7]? LI J, CHANG X, CHEN X, et al. Effects of green tea powder on production performance, egg quality, and blood biochemical parameters in laying hens[J]. Poultry science, 2023, 102(10): 102924.
[8]? CHEN X, HE K, WEI C, et al. Green tea powder decreased egg weight through increased liver lipoprotein lipase and decreased plasma total cholesterol in an indigenous chicken breed[J]. Animals, 2020, 10(3): 370.
[9]? XIA B, LIU Y, SUN D, et al. Effects of green tea powder supplementation on egg production and egg quality in laying hens[J]. Journal of applied animal research, 2018, 46(1): 927-931.
[10]? ARIANA M, SAMIE A, EDRISS M A, et al. Effects of powder and extract form of green tea and marigold, and α-tocopheryl acetate on performance, egg quality and egg yolk cholesterol levels of laying hens in late phase of production[J]. Journal of medicinal plants research, 2011,5(13): 2710-2716.
[11]? MAHLAKE S K, MNISI C M, LEBOPA C, et al. The effect of green tea (Camellia sinensis) leaf powder on growth performance, selected hematological indices, carcass characteristics and meat quality parameters of jumbo quail[J]. Sustainability, 2021, 13(13): 7080.
[12]? XUE B, SONG J, LIU L, et al. Effect of epigallocatechin gallate on growth performance and antioxidant capacity in heat-stressed broilers[J]. Archives of animal nutrition, 2017, 71(5): 362-372.
[13]? ERENER G, OCAK N, ALTOP A, et al. Growth performance, meat quality and caecal coliform bacteria count of broilerchicks fed diet with green tea extract[J]. Asian-Australasian journal of animal sciences, 2011, 24(8): 1128-1135.
[14]? AZIZ-ALIABADI F, NORUZI H, HASSANABADI A. Effect of different levels of green tea (Camellia sinensis) and mulberry (Morus alba) leaves powder on performance, carcass characteristics, immune response and intestinal morphology of broiler chickens[J]. Veterinary medicine and science, 2023, 9(3): 1281-1291.
[15]? HRNAR C, BUJKO J. Effect of different levels of green tea (Camellia sinensis) on productive performance, carcass characteristics and organs of broiler chickens[J]. Potravinarstvo, 2017, 11(1): 623-628.
[16]? HUANG J, ZHOU Y, WAN B, et al. Green tea polyphenols alter lipid metabolism in the livers of broiler chickens through increased phosphorylation of AMP-activated protein kinase[J]. Plos one, 2017, 12(10): e0187061.
[17]? SARAEI M A, SEIDAVI A, DADASHBEIKI M, et al. Response of plasma constituents and body measurement in broiler chickens fed fish oil and green tea powder[J]. Archivos de medicina veterinaria, 2016, 48(1): 61-68.
[18]? KARA, M., et al. Effect of catechins on fattening performance, meat quality, some antioxidant and blood parameters and fattening costs in Japanese quail (Coturnix coturnix japonica)[J]. British poultry science, 2016;57(4): 522-530.
[19]? JOMOVA K, RAPTOVA R, ALOMAR S Y, et al. Reactive oxygen species toxicity oxidative stress and antioxidants chronic diseases and aging[J]. Archives of toxicology, 2023, 97(10): 2499-2574.
[20]? WANG J, YANG Z, CELI P, et al. Alteration of the antioxidant capacity and gut microbiota under high levels of molybdenum and green tea polyphenols inlaying hens[J]. Antioxidants,2019, 8(10): 503.
[21]? LI Q, ZHAO T, SHI J,et al. Physicochemical characterization, emulsifying and antioxidant properties of the polysaccharide conjugates from Chin brick tea (Camellia sinensis)[J]. Food chemistry, 2022, 395: 133625.
[22]? WANG J, JIA R, CELI P, et al. Green tea polyphenol epigallocatechin-3-gallate improves the antioxidant capacity of eggs[J]. Food &Function, 2020, 11(1): 534-543.
Effect of Green Tea Powder on Laying Performance, Slaughtering Performance and Blood Biochemical Indexes of Wannan Yellow Chicken during Late Laying Period
LI Sanjun, LI Junying, QI Renrong, MA Ruiyu, LIU Wei, WAN Yi, ZHAN Kai
(Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agriculture Science, Hefei? 230031, China)
Abstract:? ?This experiment was conducted to study the effects of green tea powder from summer and autumn tea on the laying performance, slaughtering performance and blood biochemical indexes of Wannan yellow chicken during late laying period. A total of 108 62-week-old Wannan yellow chickens were randomly allocated into control group (GTP 0), GTP 0.5 group, GTP 1.0 group and GTP 1.5 group, with 3 replicates in each group, and 9 hens per replicate. The control group was fed a basic diet of corn-soybean meal, the GTP 0.5 group, GTP 1.0 group and GTP 1.5 group were fed diets containing 0.5%, 1.0% and 1.5% green tea powder, respectively. The trial lasted 8 weeks. The results showed as follows: Dietary green tea powder supplementation significantly decreased the egg production rate in the experimental group compared to the control group (P<0.05). The average egg weight in the GTP 1.0 group was higher than that of control group (P<0.05). The average egg weight and average daily feed intake in the GTP0.5 and GTP 1.5 group was lower than that of control group (P<0.05), however, the feed conversion rate was higher than that in control group(P<0.05). The abdominal fat percentage of experimental groups was decreased with the increase of GTP supplemental level, and the abdominal fat percentage of GTP 1.5 group was significantly lower than that of control group (P<0.05). The T-CH content in GTP 0.5 group was significantly lower than that in control group (P<0.05). The blood MDA content in GTP 0.5 group was significantly lower, but the contents of SOD and GSH-Px were significantly higher than that in control group (P<0.05). In summary, during the experiment, dietary green tea powder supplementation improved blood biochemical indexes and helped to reduce percentage of abdominal fat, but also reduced the laying performance.
Keywords:? Wannan yellow chicken; Green tea powder; Laying performance; Slaughtering performance; Blood biochemical indexes