羅有文,吳海濤,曹斌,卓國(guó)榮,吳錦
摘要:本試驗(yàn)旨在研究Zn-Pal對(duì)犬腸道菌群和血清免疫、抗氧化能力的影響。將20只9月齡比格犬隨機(jī)分成4組,每組5只,分別飼喂基礎(chǔ)日糧+ZnSO4(鋅添加水平為80 mg/kg,對(duì)照組)、基礎(chǔ)日糧+2.55 g/kg Zn-Pal(鋅添加水平為60 mg/kg,Zn-Pal-60)、基礎(chǔ)日糧+3.42 g/kg Zn-Pal(鋅添加水平為80 mg/kg,Zn-Pal-80)、基礎(chǔ)日糧+4.30 g/kg Zn-Pal(鋅添加水平為100 mg/kg,Zn-Pal-100)。30 d后對(duì)各組犬只腸道主要菌群和血清免疫、抗氧化指標(biāo)進(jìn)行測(cè)定。結(jié)果顯示,Zn-Pal-80組和Zn-Pal-100組大腸桿菌數(shù)量顯著低于對(duì)照組(P<0.05),血清IL-6含量顯著高于對(duì)照組(P<0.05);Zn-Pal-100組血清IgG含量顯著高于對(duì)照組(P<0.05);Zn-Pal-80組血清SOD活性顯著高于對(duì)照組(P<0.05),Zn-Pal-100組血清MDA含量顯著低于對(duì)照組(P<0.05)。由此可見(jiàn),Zn-Pal可以降低比格犬大腸桿菌數(shù)量,改善腸道微生態(tài)環(huán)境,提高比格犬血清免疫和抗氧化能力。
關(guān)鍵詞:鋅;凹凸棒石黏土;比格犬;腸道菌群;血清免疫;抗氧化
中圖分類號(hào):S829.2文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1000-4440(2021)06-1488-05
Effects of zinc-bearing palygorskite on intestinal microflora and antioxidant capability in dogs
LUO You-wen,WU Hai-tao,CAO Bin,ZHUO Guo-rong,WU Jin
(Jiangsu Agri-animal Husbandry Vocational College, Taizhou 225300,China)
Abstract:The study was conducted to explore the the effects of Zn-Pal on intestinal microflora and serum immunity, antioxidant capability in dogs.Twenty nine-month-old beagle dogs were randomly divided into four groups with five dogs in each group. They were fed with the basal diet +ZnSO4 (zinc supplemental level was 80mg/kg, control group), basal diet +2.55 g/kg Zn-Pal (zinc supplemental level was 60mg/kg, Zn-Pal-60), basal diet +3.42 g/kg Zn-Pal (zinc supplemental level was 80mg/kg, Zn-Pal-80), and basal diet +4.30 g/kg Zn-Pal (zinc supplemental level was 100mg/kg, Zn-Pal-100), respectively. After 30 days, the main serum immunity, antioxidant indices and intestinal microflora of beagle dogs in each group were determined. The results showed that the number of Escherichia coli in groups Zn-Pal-80 and Zn-Pal-100 was significantly lower than that in control group (P<0.05), the serum IL-6 content in groups Zn-Pal-80 and Zn-Pal-100 was significantly higher than that in control group (P<0.05), and the serum IgG content in group Zn-Pal-100 was significantly higher than that in control group (P<0.05). The serum SOD activity of group Zn-Pal-80 was significantly higher than that in control group (P<0.05). The serum MDA content of group Zn-Pal-100 was significantly lower than that in control group (P<0.05). In conclusion, Zn-Pal can improve the intestinal environment, reduce the number of E.coli and improve the serum immunity and antioxidant capacity of beagle dogs.
Key words:zinc;palygorskite;beagle dog;intestinal microflora;serum immunity;antioxidant
鋅是犬的6種必需微量礦物元素之一,對(duì)犬的正常生理代謝起著重要的作用[1]。在動(dòng)物體內(nèi)鋅有許多功能,它是200多種含鋅酶的輔助因子和催化劑,并參與細(xì)胞分裂、有機(jī)物代謝等,也是各種蛋白質(zhì)的主要成分(生長(zhǎng)轉(zhuǎn)錄因子、受體、細(xì)胞因子、酶),是它們發(fā)揮生物活性所必需的物質(zhì)[1-3]。鋅也是寵物生長(zhǎng)、抗氧化系統(tǒng)和正常免疫功能所必需的物質(zhì)[4],此外,研究結(jié)果表明,鋅離子還具有一定的抗菌作用[5-6]。鋅在寵物飼料中來(lái)源各異,不同形式的鋅添加到日糧中均能改善動(dòng)物腸道菌群[4、7-8]。抗生素在飼料中的普遍應(yīng)用極大地推動(dòng)了畜牧業(yè)的發(fā)展,但其帶來(lái)的負(fù)面影響(抗生素殘留、免疫抑制、細(xì)菌耐藥性等)也逐漸顯露出來(lái)。自2020年7月中國(guó)發(fā)布“無(wú)抗計(jì)劃”后,尋找和研發(fā)抗生素的替代品成為近年研究熱點(diǎn),具有抗菌作用的無(wú)機(jī)抗菌劑是其中最具有應(yīng)用和研究前景的一個(gè)領(lǐng)域。
非金屬礦由于特殊的顯微結(jié)構(gòu)而具有較大的比表面積,表現(xiàn)出較強(qiáng)的吸附性和離子交換性,常被用作緩釋劑的載體[9-10]。凹凸棒石黏土是一種結(jié)構(gòu)中富含可交換離子的非金屬黏土礦[11-12],用離子交換法制得的載鋅凹凸棒石黏土(Zn-Pal),是動(dòng)物日糧鋅的來(lái)源之一。目前,寵物日糧中常以無(wú)機(jī)鋅的形式添加以滿足需要,但由于日糧中鋅的添加量高使得糞便中鋅排泄量偏高從而導(dǎo)致環(huán)境問(wèn)題[12-13]。研究者發(fā)現(xiàn),Zn-Pal不僅可以作為鋅的來(lái)源,而且可對(duì)病原菌表現(xiàn)出持久的抗菌性,并在相關(guān)領(lǐng)域受到了廣泛的關(guān)注[9、14]。Yang 等[15]報(bào)道,載鋅凹凸棒石黏土添加到雞日糧中可以提高肉品質(zhì)量和肌肉中鋅的沉積量,并能增強(qiáng)肝臟抗氧化能力。研究結(jié)果表明,載鋅凹凸棒石黏土是肉雞良好的鋅來(lái)源[9],日糧中添加鋅改進(jìn)的黏土,可以提高肉雞生產(chǎn)性能,抑制病原菌的生長(zhǎng),提高腸道抗氧化能力和免疫功能[8、16]。迄今為止,國(guó)內(nèi)外鮮有關(guān)于Zn-Pal調(diào)控犬腸道菌群、免疫和抗氧化能力的報(bào)道。因此,本研究旨在探討Zn-Pal對(duì)比格犬腸道菌群、血清免疫和抗氧化指標(biāo)的影響,為Zn-Pal在犬日糧中的應(yīng)用提供依據(jù)。
1材料與方法
1.1試驗(yàn)材料
本試驗(yàn)所用凹凸棒石黏土由江蘇神力特生物科技股份有限公司提供。Zn-Pal參照顏瑞[17]、Zhang等[18]的方法進(jìn)行制備,凹凸棒石黏土所負(fù)載的鋅量為23.57 mg/g。
1.2試驗(yàn)設(shè)計(jì)
選取9月齡健康比格犬(Beagle)20只,公母各10只,隨機(jī)分成4組。對(duì)照組:基礎(chǔ)日糧+ZnSO4(鋅添加水平為80 mg/kg);Zn-Pal-60組:基礎(chǔ)日糧+2.55 g/kg Zn-Pal(鋅添加水平為60 mg/kg);Zn-Pal-80組:基礎(chǔ)日糧+3.42 g/kg Zn-Pal(鋅添加水平為80 mg/kg);Zn-Pal-100組:基礎(chǔ)日糧+4.30 g/kg Zn-Pal(鋅添加水平為100 mg/kg)。日糧參照2008年美國(guó)飼料管理委員會(huì)(AAFCO)制訂的犬營(yíng)養(yǎng)標(biāo)準(zhǔn)進(jìn)行配制,飼養(yǎng)期為預(yù)試期7 d+正試期30 d。日糧組成及營(yíng)養(yǎng)指標(biāo)見(jiàn)表1。
1.3飼養(yǎng)管理
所有供試比格犬單籠飼養(yǎng)于試驗(yàn)房,試驗(yàn)籠清洗干凈并消毒。預(yù)飼期7 d,根據(jù)試驗(yàn)犬在5 min內(nèi)的自由采食量確定每次供給量。每日上午8時(shí)和下午16時(shí)給料飼喂,自由飲水。
1.4指標(biāo)測(cè)定
1.4.1腸道菌群的測(cè)定于正試期30 d使用無(wú)菌便盒收集新鮮糞便約2~3 g,無(wú)菌稱取糞樣0.2 g于滅菌離心管中,用無(wú)菌生理鹽水以10倍比例按梯度稀釋至1×104、1×105、1×106倍,分別取100 μl稀釋液接種于平板培養(yǎng)皿中,進(jìn)行微生物培養(yǎng)。大腸桿菌在MAC培養(yǎng)基上37 ℃培養(yǎng)24 h,乳酸桿菌和雙歧桿菌分別在MRS和YPY培養(yǎng)基上37 ℃培養(yǎng)48 h,培養(yǎng)結(jié)束后計(jì)數(shù),結(jié)果用每1 g糞便樣品中細(xì)菌數(shù)量的對(duì)數(shù)表示。
1.4.2血清免疫指標(biāo)的測(cè)定于正試期30 d對(duì)供試犬只前肢靜脈留置針采血,采集血液約8 ml于離心管中,而后4 500 r/min離心10 min,用微量移液器轉(zhuǎn)移分離得到的血清并放置于-20 ℃冰箱待測(cè)。血清IgG、白介素-1 (IL-1 )、白介素-2 (IL-2 )、白介素-6 (IL-6 )和腫瘤壞死因子-α(TNF-α)采用酶聯(lián)免疫法試劑盒進(jìn)行測(cè)定。
1.4.3血清抗氧化指標(biāo)的測(cè)定于正試期30 d對(duì)供試犬只前肢靜脈留置針采血,采集血液約8 ml于離心管中,而后4 500 r/min離心10 min,用微量移液器轉(zhuǎn)移分離得到的血清并放置于-20 ℃冰箱待測(cè)。血清中總抗氧化力(T-AOC)、超氧化物歧化酶(SOD)活性、谷胱甘肽過(guò)氧化物酶(GSH-Px)活性和丙二醛(MDA)含量按試劑盒說(shuō)明書(shū)進(jìn)行測(cè)定。
1.5數(shù)據(jù)統(tǒng)計(jì)與分析
試驗(yàn)數(shù)據(jù)錄入Microsoft Excel后采用SPSS19.0統(tǒng)計(jì)軟件對(duì)樣本均數(shù)進(jìn)行t檢驗(yàn),結(jié)果以平均值±標(biāo)準(zhǔn)差表示。
2結(jié)果與分析
2.1Zn-Pal對(duì)犬腸道菌群的影響
表2顯示Zn-Pal-80組和Zn-Pal-100組比格犬腸道大腸桿菌數(shù)量顯著低于對(duì)照組(P<0.05),各組比格犬腸道乳酸桿菌和雙歧桿菌數(shù)量無(wú)顯著差異(P>0.05)。
2.2Zn-Pal對(duì)犬血清免疫相關(guān)指標(biāo)的影響
表3顯示Zn-Pal-80組和Zn-Pal-100組比格犬血清IL-6含量顯著高于對(duì)照組(P<0.05),Zn-Pal-100組比格犬血清IgG含量顯著高于對(duì)照組(P<0.05);各組比格犬血清IL-1含量無(wú)顯著差異(P>0.05),各組比格犬血清IL-2、TNF-α含量無(wú)顯著差異(P>0.05)。
2.3Zn-Pal對(duì)犬血清抗氧化指標(biāo)的影響
表4顯示Zn-Pal-80組比格犬血清SOD活性顯著高于對(duì)照組(P<0.05),Zn-Pal-100組比格犬血清SOD活性比對(duì)照組高12.73%(P>0.05)。Zn-Pal-100組MDA含量顯著低于對(duì)照組(P<0.05),Zn-Pal-80組與對(duì)照組差異不顯著(P>0.05)。比格犬血清T-AOC和GSH-Px活性各組間無(wú)顯著差異(P>0.05)。
3討論
3.1Zn-Pal對(duì)犬腸道菌群的影響
動(dòng)物腸道中棲息著100多種菌群,這些微生物構(gòu)成了腸道的正常微生態(tài)菌群。大腸桿菌是腸道菌群中的常見(jiàn)成員,但大腸桿菌過(guò)多會(huì)引起菌群失調(diào),破壞腸道微生態(tài)平衡,并可能導(dǎo)致動(dòng)物產(chǎn)生疾病[19]。雙歧桿菌和乳酸桿菌能調(diào)節(jié)動(dòng)物腸道微生態(tài)平衡,增強(qiáng)腸道對(duì)有害菌的抵抗力。近年來(lái),金屬離子銀、鋅、銅等交換黏土礦物作為無(wú)機(jī)抗菌材料在畜牧業(yè)中得到了廣泛的應(yīng)用[20-21]。研究發(fā)現(xiàn),在動(dòng)物飼料中添加含鋅黏土礦物作為抗生素替代品,具有明顯的抗菌效果[8]。本試驗(yàn)發(fā)現(xiàn),日糧添加鋅水平為80 mg/kg、100 mg/kg的Zn-Pal時(shí),犬腸道大腸桿菌數(shù)量顯著下降。Zn-Pal通過(guò)其吸附性和鋅離子的釋放而表現(xiàn)出抗菌能力[21],蛋白質(zhì)在代謝過(guò)程中產(chǎn)生的氨或腸道毒素被Pal吸附,改善了腸道微生態(tài)環(huán)境,大腸桿菌的增殖受到抑制,使得Zn-Pal對(duì)微生物區(qū)系產(chǎn)生影響[22],從而減少腸道食糜中有害細(xì)菌的數(shù)量[23]。此外,Zn-Pal試驗(yàn)組大腸桿菌數(shù)量下降,也可能與鋅離子的抑菌性和凹凸棒石黏土的緩釋性有關(guān),Zn-Pal中的鋅離子進(jìn)入動(dòng)物腸道后開(kāi)始解吸,解吸后的鋅離子可以停留在Pal表面,也可以游離在腸道內(nèi),與常規(guī)鋅源相比具有更好的抗菌效果。
3.2Zn-Pal對(duì)犬血清免疫功能的影響
血清免疫是機(jī)體體液免疫的重要組成部分,IgG是血清和細(xì)胞外液中含量最高的免疫球蛋白,是血清免疫的主要指標(biāo)。研究結(jié)果表明,日糧鋅源的補(bǔ)充可以提高血清免疫分子含量[24]。本試驗(yàn)發(fā)現(xiàn)日糧鋅添加水平為100 mg/kg的Zn-Pal處理組犬血清IgG含量顯著高于對(duì)照組,表明Zn-Pal可作為鋅源提高犬血清IgG含量。TNF-α是一種對(duì)某些腫瘤細(xì)胞具有細(xì)胞毒性作用的因子,具有增強(qiáng)機(jī)體局部免疫、殺傷腫瘤細(xì)胞等作用[25]。IL-6在免疫應(yīng)答中能促進(jìn)肝細(xì)胞產(chǎn)生急性期蛋白,參與炎癥反應(yīng),提高機(jī)體對(duì)局部感染的防御能力[25]。本試驗(yàn)結(jié)果顯示,日糧添加鋅水平為80 mg/kg、100 mg/kg的Zn-Pal可以顯著提高犬血清中IL-6含量,表明Zn-Pal可以提高犬血清免疫分子含量。Zhang 等[26]的研究結(jié)果也表明Zn-Pal可以提高團(tuán)頭魴血清免疫功能。
3.3Zn-Pal對(duì)犬抗氧化能力的影響
鋅是動(dòng)物體內(nèi)許多酶和激素的組成成分和激活劑,在犬的生長(zhǎng)、免疫和抗氧化功能中起著重要作用[4]。一般而言,健康動(dòng)物機(jī)體氧自由基的產(chǎn)生和消除處于動(dòng)態(tài)平衡狀態(tài)[27]。動(dòng)物生長(zhǎng)過(guò)程中的不良因素如高溫、寒冷、運(yùn)輸?shù)瓤墒箘?dòng)物體內(nèi)產(chǎn)生大量的羥基自由基,破壞動(dòng)物體內(nèi)自由基的平衡狀態(tài)。SOD是動(dòng)物酶促抗氧化體系的重要氧化酶,能有效清除自由基,有助于減少和阻止脂質(zhì)過(guò)氧化反應(yīng)[28]。在本研究中,日糧添加80 mg/kg的Zn-Pal處理組血清SOD活性顯著高于對(duì)照組,添加100 mg/kg的Zn-Pal處理組血清SOD活性比對(duì)照組高12.73%。Zhang等[26]研究Zn-Pal對(duì)團(tuán)頭魴生長(zhǎng)、抗氧化能力和抗運(yùn)輸應(yīng)激的影響時(shí)發(fā)現(xiàn),日糧中添加Zn-Pal可以提高血清SOD和Cu/Zn-SOD活性。這可能是因?yàn)榘纪拱羰ね恋奈骄忈屝蕴岣吡虽\在犬體內(nèi)的利用率,而鋅又跟體內(nèi)許多酶(包括抗氧化酶)的活性相關(guān),從而提高了機(jī)體抗氧化酶清除自由基的能力。本試驗(yàn)還發(fā)現(xiàn),日糧添加鋅水平為80 mg/kg、100 mg/kg的Zn-Pal,犬血清MDA含量均有不同程度下降。Yang等[15]報(bào)道,以Zn-Pal作為鋅源添加到肉雞日糧中,肉雞血清中MDA含量顯著下降, SOD活性均呈增加趨勢(shì),同時(shí)肝臟中SOD活性也顯著增加,與本試驗(yàn)結(jié)果類似。由此可知,日糧添加Zn-Pal可以提高犬血清抗氧化功能。
日糧添加Zn-Pal可以降低犬腸道中大腸桿菌數(shù)量,改善腸道微生態(tài)平衡,可以提高血清免疫和抗氧化能力。Zn-Pal可以作為日糧鋅源滿足犬對(duì)鋅的需要,但Zn-Pal作為鋅源的生物學(xué)利用率是否高于無(wú)機(jī)鋅還有待于進(jìn)一步研究。
參考文獻(xiàn):
[1]丁麗敏,夏兆飛. 犬貓營(yíng)養(yǎng)需要[M].2版.北京:中國(guó)農(nóng)業(yè)大學(xué)出版社,2017.
[2]FUKADA T, YAMASAKI S, NISHIDA K.,et al. Zinc homeostasisand signaling in health and diseases[J]. J Biol Inorg Chem, 2011, 16:1123-1134.
[3]VALLEE B L, AULD D S. Zinc coordination, function, and structure of zinc enzymes and other proteins[J]. Biochemistry, 1990, 29:5647-5659.
[4]趙治平,黃克和,任志華. 富硒鋅益生菌對(duì)犬的全血硒鋅含量與抗氧化能力和腸道菌群的影響[J].營(yíng)養(yǎng)學(xué)報(bào),2009,31(2):159-163.
[5]SODERBERG T A,SUNZEL B,HOLM S, et al. Antibacterial effect of zinc oxide in vitro[J]. Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery, 1990, 24(3): 193-197.
[6]YAO J,LIU Y,LING H, et al. The effect of zinc(II) on the growth of E-coli studied by microcalorimetry[J]. Journal of Thermal Analysis and Calorimetry, 2005, 79(1): 39-43.
[7]FENG Y,MIN L,ZHANG W, et al. Zinc oxide nanoparticles influence microflora in ileal digesta and correlate well with blood metabolites[J]. Front Microbiol, 2017, 8: 992.
[8]TANG Z G, WEN C,WANG L C, et al. Effects of zinc-bearing clinoptilolite on growth performance, cecal microflora and intestinal mucosal func-tion of broiler chickens[J].Anim Feed Sci Technol, 2014, 189: 98-106.
[9]YAN R, ZHANG L,YANG X. Bioavailability evaluation of zinc-bearing palygorskite as a zinc source for broiler chickens[J]. Appl? Clay Sci, 2016,119:155-160.
[10]ZHOU C H, KEELING J. Fundamental and applied research on clay minerals: from climate and environment to nanotechnology[J]. Appl? Clay Sci, 2013,74: 3-9.
[11]GIUSTETTO R,WAHYUDI O. Sorption of red dyes on palygorskite: synthesis and stability of red/purple Mayan nanocomposites[J]. Microporous Mesoporous Mater, 2011,142:221-235.
[12]APINES M J,SATOH S,KIRON V,et al. Bioavailability of amino acids chelated and glass embedded zinc to rainbow trout, oncorhynchus mykiss, fingerlings[J]. Aquac? Nutr,2001,7:221-228.
[13]CARLSON M S,BOREN C A,WU C, et al. Evaluation of various inclusion rates of organic zinc either as polysaccharide or proteinate complex on the growth performance, plasma, and excretion of nursery pigs[J]. J? Anim? Sci, 2004,82: 1359-1366.
[14]JIAO L,KE Y, XIAO K, et al. Effects of zinc-exchanged mon-tmorillonite with different zinc loading capacities on growth performance, intestinal microbiota, morphology and permeability in weaned piglets[J].Appl? Clay Sci, 2015, 112:40-43.
[15]YANG W,CHEN Y,CHENG Y, et al. Effects of zinc bearing palygorskite supplementation on the growth performance, hepatic mineral content, and antioxidant status of broilers at early age[J]. Asian Australas? J? Anim? Sci,2017,30:1006-1012.
[16]HU C,QIAN Z,SONG J,et al. Effects of zinc oxide-montmorillonite hybrid on growth performance, intestinal structure, and function of broiler chicken[J].Poult? Sci, 2013,92:143-150.
[17]顏瑞. 固相載鋅凹凸棒石茹土對(duì)肉雞鋅生物利用率及免疫調(diào)節(jié)機(jī)制的研究[D]. 南京:南京農(nóng)業(yè)大學(xué),2016.
[18]ZHANG R,ZHOU Y,JIANG X, et al. Evaluation of zinc-bearing palygorskite effects on growth performance, nutrient retention, meat quality, and zinc accumulation in blunt snout bream Megalobrama amblycephala[J].Clay Clay Min, 2018, 66:274-285.
[19]丁維俊,周邦靖,翟慕東,等. 參苓白術(shù)散對(duì)小鼠脾虛模型腸道菌群的影響[J].北京中醫(yī)藥大學(xué)學(xué)報(bào),2006, 29(8): 530-533.
[20]JIAO L,KE Y,XIAO K,et al. Effects of zinc-exchanged mon-tmorillonite with different zinc loading capacities on growth performance, intestinal microbiota, morphology and permeability in weaned piglets[J]. Appl Clay Sci, 2015,112:40-43.
[21]JIAO L,LIN F,CAO S,et al. Preparation, characterization, antimicrobial and cytotoxicity studies of copper/zinc-loaded mon-tmorillonite[J]. J Anim? Sci Biotechnol, 2017, 8: 27.
[22]XIA M S, HU C H, XU Y. Adsorption of Aeromonas hydrophila by copper-bearing montmorillonite clays[J]. J? Inorg Mater, 2007,22: 652-656.
[23]WANG W,TIAN G,ZONG L, et al. Mesoporous hybrid Zn-silicate derived from red palygorskite clay as a high-efficient adsorbent for anti-biotics[J]. Microporous Mesoporous Mater, 2016,234:317-325.
[24]FENG J,MA W Q,NIU H H, et al. Effects of zinc glycine chelate on growth, hematological, and immunological characteristics in broilers[J].Biological Trace Element Research, 2010, 133(2):203-211.
[25]嚴(yán)思益. 免疫學(xué)筆記精要[M].北京:化學(xué)工業(yè)出版社,2009.
[26]ZHANG R Q, JIANG Y, LIU W J, et al. Evaluation of zinc-bearing palygorskite effects on the growth, immunity,antioxidant capability, and resistance to transport stress in blunt snout bream[J]. Aquaculture, 2021,532:963-973.
[27]HALLIWELL B,WHITEMAN M. Measuring reactive species and oxidative damage in vivo and in cell culture: how should you do it and what do the results mean[J]. Br? J Pharmacol, 2004, 142: 231-255.
[28]謝繼青,李玉華,楊春梅,等. 超氧化物歧化酶的藥理作用[J].中國(guó)生化藥物雜志,2009,30(1):72-75.
(責(zé)任編輯:陳海霞)
收稿日期:2021-04-12
基金項(xiàng)目:江蘇省高校自然科學(xué)研究面上項(xiàng)目(20KJD230002)
作者簡(jiǎn)介:羅有文(1981-),男,福建上杭人,碩士,講師,主要從事寵物營(yíng)養(yǎng)研究。(E-mail)ywdongke@sina.com