高钙高蛋白日粮对肉仔鸡生长性能、血清生理生化指标和盲肠菌群的影响

【目的】旨在研究饲喂高钙、高蛋白日粮对肉仔鸡生长性能、血清生化指标、抗氧化指标及盲肠菌群的影响。【方法】选取160只体质量相近的健康1日龄肉仔鸡,随机分为4组,每组5个重复,每个重复8只,分别为对照组(CP含量21%,Ca含量1%)、高蛋白组(CP含量31%,Ca含量1%)、高钙组(CP含量21%,Ca含量5%)和高钙高蛋白组(CP含量31%,Ca含量5%)。【结果】结果表明:(1)仔鸡21日龄时,对照组鸡的平均体质量、日增质量、日采食量均极显著高于其他3组(P0.01),料重比极显著小于高钙高蛋白组(P0.01);高蛋白组鸡的平均体质量、日采食量显著高于高钙组和高钙高蛋白组(P0.05);高钙组鸡的平均体质量、日增质量显著高于高钙高蛋白组(P0.05)而料重比显著小于高钙高蛋白组(P0.05)。(2)高钙、高蛋白日粮可导致仔鸡血清中AST、ALT、UA、CREA-S、UREA、GSH-Px、SOD、MDA、T-AOC、XOD活性或含量异常。(3)IlluminaMiseq高通量测序结果表明,仔鸡盲肠中的厚壁菌门Firmicutes、变形菌门Proteobacteria、厌氧杆菌属Barnesiella、另枝菌属Alistipes、粪便杆菌属Faecalibacterium、理研菌属Rikenella、卟啉单胞菌属Porphyromonas、梭状芽孢杆菌属第十八类群Clostridium_XVIII、嗜碱菌Alkaliphilus、颤杆菌克属Oscillibacter、梭状芽孢杆菌Clostridium的物种丰富度发生显著变化(P0.01或P0.05);PICRUSt功能预测结果显示,葡萄糖和一些氨基酸和核苷酸的合成代谢出现紊乱。(4)对照组鸡肝肾组织正常,结构清晰;其他三组鸡肝肾组织发生不同程度的病变。【结论】高钙高蛋白日粮导致仔鸡生长性能、抗氧化能力降低,肝肾功能受损,引起仔鸡高尿酸血症及盲肠菌群结构异常。     

低聚原花青素对肉鸡生长性能、免疫机能及抗氧化性能的影响

【目的】研究低聚原花青素(OPC)对肉鸡生长性能、免疫机能及抗氧化性能的影响.【方法】选取1日龄艾拔益加(AA)肉鸡(公雏)200只随机分为4个组,每组5个重复,每个重复10只鸡.分别饲喂添加0,5,10,15mg/kg OPC的饲粮,进行为期42d的试验.测定了平均日增质量、平均日采食量、料重比等生长性能指标,总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(T-SOD)、丙二醛(MDA)等血浆抗氧化指标以及免疫器官指数、单核吞噬细胞活性、血浆溶菌酶等免疫指标.【结果】1)5、10mg/kg OPC可显著提高22~42日龄平均日增质量(ADG)(P0.05),以10 mg/kg OPC组最高,显著降低平均日采食量(ADFI)及料重比(F/G)(P0.05),以10mg/kg OPC组最低;5、10 mg/kg OPC均可显著降低1~42日龄ADFI、F/G(P0.05),以10mg/kg OPC组最低;2)10mg/kg OPC组可显著提高21d血浆总抗氧化能力(T-AOC);10、15mg/kg OPC可显著提高42d谷胱甘肽过氧化物酶(GSH-Px)水平、超氧化物歧化酶(T-SOD)水平、T-AOC水平;3)各OPC剂量均可显著提高肉鸡胸腺指数水平(P0.05),且10mg/kg OPC组优于15mg/kg OPC组.10mg/kg OPC可显著提高脾脏指数水平(P0.05);4)10、15mg/kg OPC组可显著提高廓清指数水平(P0.05),且10mg/kg OPC组优于15mg/kg OPC组.10mg/kg OPC组可显著提高吞噬指数水平(P0.05);5)5、10mg/kg OPC组均可显著提高血浆溶菌酶含量(P0.05),以10mg/kg OPC组最优.【结论】10mg/kg OPC对肉鸡1~42d的生长性能及免疫机能提升最显著,15mg/kg OPC对肉鸡血浆抗氧化提升最显著.     

加味二术散对断奶仔猪空肠黏膜抗氧化能力和免疫力的影响

【目的】研究加味二术散对断奶仔猪空肠黏膜抗氧化能力和免疫力的影响,为防治断奶仔猪应激综合症提供有效方剂。【方法】将45头断奶仔猪随机分为空白对照组(饲喂基础日粮)、中药组(饲喂基础日粮中添加质量分数0.3%加味二术散的日粮)和抗生素组(饲喂基础日粮中添加质量分数0.5%硫酸粘杆菌素的日粮)。于试验第7,14和21天,分别从各组随机选取3头仔猪放血致死,采集各组仔猪的空肠黏膜,测定其总超氧化物歧化酶(TSOD)、过氧化氢酶(CAT)及总抗氧化能力(T-AOC)、丙二醛(MDA)、白介素-2(IL-2)和分泌型免疫球蛋白A(SIg A),研究加味二术散对断奶仔猪空肠黏膜抗氧化能力和免疫力的影响。【结果】中药组仔猪空肠黏膜中T-SOD酶活力在第7和14天显著高于空白对照组(P0.05),在第7,14和21天均显著高于抗生素组(P0.05);CAT在试验第7天显著高于空白对照组和抗生素组(P0.05);T-AOC在试验第14天显著高于空白对照组和抗生素组(P0.05);MDA含量在试验第14天显著低于抗生素组和空白对照组(P0.05),在第7天时显著低于抗生素组(P0.05)。中药组仔猪空肠黏膜中IL-2和SIg A含量在试验的第14天均显著高于空白对照组和抗生素组(P0.05)。【结论】加味二术散可有效改善断奶仔猪空肠黏膜的抗氧化能力和免疫力。     

大豆异黄酮对早期断奶仔猪生长性能、抗氧化功能及肠粘膜形态结构的影响

【目的】研究饲粮中添加大豆异黄酮对早期断奶仔猪生长性能和抗氧化作用及免疫功能的影响。【方法】选用160只5.5 kg 21日龄断奶的(杜×长×大)三元杂交仔猪,根据体重和性别随机分成5组,每组4个重复(公母各4只)。各处理组饲粮大豆异黄酮添加水平分别为0(空白对照组)、10、20、40、80 mg·kg-1。试猪饲养至7、42d时每个重复分别选取平均体重的试猪屠宰并取样测定。【结果】断奶后8—42 d和整个试验期阶段,大豆异黄酮40 mg·kg-1组平均日采食量显著高于空白对照组、10 mg·kg-1大豆异黄酮组和20 mg·kg-1大豆异黄酮组(P0.05)。断奶后8—42 d时,大豆异黄酮20 mg·kg-1组料重比显著低于空白对照组和80 mg·kg-1大豆异黄酮组(P0.05)。断奶后7d,肝脏中丙二醛(MDA)含量随大豆异黄酮添加水平提高有降低的趋势,其中添加大豆异黄酮40和80 mg·kg-1组试验猪肝脏中的MDA含量显著低于空白对照组和10 mg·kg-1大豆异黄酮组。添加大豆异黄酮20 mg·kg-1组仔猪血清超氧化物歧化酶(SOD)活性显著高于空白对照组、40 mg·kg-1大豆异黄酮组和80mg·kg-1大豆异黄酮组(P0.05)。添加大豆异黄酮10 mg·kg-1组肝脏组织谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组和80 mg·kg-1大豆异黄酮组(P0.05)。断奶后8—42 d时,20 mg·kg-1大豆异黄酮组试验猪料重比显著低于空白对照组和80 mg·kg-1大豆异黄酮组(P0.05)。断奶42d时,添加大豆异黄酮40 mg·kg-1组血清SOD活性显著高于空白对照组、10 mg·kg-1大豆异黄酮组和80 mg·kg-1大豆异黄酮组(P0.05)。大豆异黄酮20 mg·kg-1组肝脏的GSH-Px活性显著高于空白对照组和80 mg·kg-1大豆异黄酮组(P0.05)。断奶后42d,大豆异黄酮40和80 mg·kg-1组的空肠SOD活性显著高于对照组(P0.05);添加大豆异黄酮40 mg·kg-1组空肠的GSH-Px活性显著高于对照组和10 mg·kg-1大豆异黄酮组(P0.05);饲粮大豆异黄酮对空肠的金属硫蛋白(MT)含量有显著影响作用,其中大豆异黄酮10 mg·kg-1组空肠的MT含量显著高于空白对照组(P0.05)。断奶后7、42d对照组仔猪十二指肠绒毛成舌状排列,绒毛顶端凹陷且脱落严重,各处理组与对照组相比,十二指肠绒毛损伤程度降低,其中40 mg·kg-1组仔猪十二指肠绒毛最完整,成柱状排列。添加大豆异黄酮对断奶仔猪42d的血液中CD4+的水平有显著影响作用,对淋巴细胞转化率、CD8+、CD4+/CD8+无显著影响(P0.05),其中大豆异黄酮10和20 mg·kg-1组血液中CD4+水平显著低于空白对照组和80 mg·kg-1大豆异黄酮组(P0.05)。【结论】饲粮中添加大豆异黄酮能够提高断奶仔猪的生长性能,增强机体的抗应激能力,对肠绒毛有一定的保护作用,早期断奶仔猪大豆异黄酮适宜添加量为40mg·kg-1。     

大豆异黄酮对哺乳母猪生产性能及抗氧化性能的影响

试验选用体况相近、预产期接近的长×大二元杂交母猪14头、长白母猪28头、大白母猪26头,3个品种猪均随机分为2组,分别添加大豆异黄酮0mg·kg-(1对照组)和15mg·kg-1,研究饲粮中添加大豆异黄酮对哺乳母猪生产性能、抗氧化性能的影响。试验期为母猪泌乳第4~21天。试验结果表明,添加大豆异黄酮对母猪采食量、背膘损失无显著影响(P0.05);大豆异黄酮组长×大二元杂交母猪泌乳第21天泌乳量显著高于对照组(P0.05),其所哺乳仔猪21日龄断奶窝均个体重显著高于对照组(P0.05),长白、大白母猪所哺乳仔猪断奶窝个体重显著提高;大豆异黄酮组二元杂母猪泌乳第10天乳蛋白含量显著升高,乳糖、乳脂含量与对照组差异不显著(P0.05);母猪血浆总抗氧化能力提高(P0.05),肝脏过氧化氢酶(CAT)活性上升(P0.05),丙二醛(MDA)含量下降(P0.05)。研究结果提示,在哺乳期母猪饲粮中添加大豆异黄酮可改善母猪抗氧化性能,提高母猪泌乳性能,改善哺乳仔猪生长性能。     

灵芝孢子粉和大豆异黄酮对文昌鸡生长性能、肉品质及抗氧化能力的影响

为研究灵芝孢子粉与大豆异黄酮对110~140日龄文昌鸡生长性能、肉品质与抗氧化能力的影响,试验选取540只110日龄文昌母鸡,随机分成3个处理组,每组6个重复,每个重复30只,试验周期30天,对照组饲喂基础日粮,处理组分别在基础饲粮中添加500 mg/kg灵芝孢子粉和300 mg/kg大豆异黄酮预混剂,试验期满后,测定试鸡生长性能,采集试鸡血浆、胸肌样品,测定血液与胸肌抗氧化指标、胸肌肉质性状、肉感官评定及货架期指标。结果表明,与对照组相比,1)大豆异黄酮组试鸡的生长末重与平均日增重均显著增加(P<0.05),料重比降低(P<0.05);2)灵芝孢子粉显著提高试鸡胸肌宰后24 h的pH(P<0.05)、降低剪切力(P<0.05);大豆异黄酮显著降低胸肌宰后45 min的a^*值(P<0.05),提高胸肌宰后24 h的L^*值和pH(P<0.05);3)灵芝孢子粉组试鸡的肉汤鲜味评分显著提高(P<0.05);4)灵芝孢子粉可显著降低文昌鸡胸肌宰后24 h的丙二醛(MDA)与宰后45 min的挥发性盐基氮含量(P<0.05);大豆异黄酮显著降低试鸡胸肌宰后45 min和24 h的MDA含量(P<0.05);5)饲粮添加灵芝孢子粉与大豆异黄酮显著降低了文昌鸡血浆MDA含量(P<0.05),灵芝孢子粉还增加了血浆谷胱甘肽含量(P<0.05)。综上,500 mg/kg灵芝孢子粉和300 mg/kg大豆异黄酮预混剂均可提高文昌鸡的抗氧化能力,改善肌肉品质。二者比较,500 mg/kg灵芝孢子粉作用更优。     

饲粮苏氨酸水平对兴义矮脚鸡生长和养分消化的影响

【目的】探明苏氨酸(Thr)水平对1～4和5～7周龄兴义矮脚鸡生长和养分代谢的影响,为兴义矮脚鸡饲养标准的制定奠定基础。【方法】采用单因子设计,选取144只0日龄健康、体重相近的兴义矮脚鸡雏鸡,随机分成4组,1～4周龄1～4组兴义矮脚鸡分别饲喂苏氨酸水平为0.80%、0.87%、0.94%、1.07%饲粮,5～7周龄饲喂水平分别为0.70%、0.80%、0.90%、1.0%,测定兴义矮脚鸡的生长性能和养分代谢率。【结果】在1～4周龄,随着Thr水平提高,兴义矮脚鸡的日增重(ADG)和日均采食量(ADFI)随之增加,1.07%和0.94%水平组ADG和ADFI均显著高于0.87%和0.80%组(P0.05),1.07%组的饲料转换效率高于其他各组(P0.05);在5～7周龄,兴义矮脚鸡的ADG和ADFI亦随Thr水平增加而提高,日增重亦有提高趋势,以1.00%水平组的日增重为最高,但与0.90%水平无显著差异(P0.05),料重比(F/G)以0.70%水平的最低(P0.05),显著低于其他3组。【结论】兴义矮脚鸡在1～4周龄时,苏氨酸适宜水平为0.94%;5～7周龄,适宜苏氨酸水平则为0.90%。     

外源5′-尿苷酸对断奶仔猪生长性能及抗氧化能力的影响

【目的】研究外源5′-尿苷酸对断奶仔猪生长性能和抗氧化能力的影响。【方法】将90头28日龄断奶的"杜×长×大"三元杂交断奶仔猪,随机分成3组,每组3个重复,对照组饲喂基础日粮,试验Ⅰ和Ⅱ组在基础日粮中分别添加质量分数0.15%,0.25%5′-尿苷酸日粮,试验期为28d。测定断奶仔猪生长性能、腹泻频率,以及试验开始后第7,14和28天断奶仔猪血清中超氧化物歧化酶(SOD)活性、总抗氧化能力(T-AOC)、过氧化氢酶(CAT)活性和MDA含量。【结果】与对照组相比,Ⅱ组断奶仔猪平均日增质量、日采食量均呈上升趋势,料重比、腹泻频率均呈下降趋势,但差异不显著(P>0.05),第7和14天,Ⅱ组断奶仔猪血清SOD活性分别较对照组提高20.89%和25.35%(P<0.05);第14天T-AOC和第28天CAT活性均显著高于对照组(P<0.05),第14天MDA含量显著低于对照组(P<0.05)。【结论】日粮中添加质量分数0.25%5′-尿苷酸,可以提高断奶仔猪的生长性能和抗氧化能力。     

相对湿度对肉鸡生长和屠宰性能及肉品质的影响

【目的】研究舍内相对湿度(RH)对肉鸡生产性能、屠宰性能和肉品质的影响,为标准化养殖环境控制提供数据支持。【方法】将270只1日龄健康AA肉公鸡随机分成正常对照组(60%RH)、低湿组(30%RH)和高湿组(90%RH)3组,每组6个重复,每个重复15只。试验在人工气候实验舱内进行,试验期为42d。在肉鸡21和42日龄时,测定不同RH下肉鸡生产性能、屠宰性能和肉品质指标。【结果】1~21日龄阶段,与对照组相比,低湿组肉鸡平均日增重(ADG)显著降低(P0.05),料重比(F/G)显著增加(P0.05);高湿组ADG、F/G、平均日采食量(ADFI)差异均不显著(P0.05)。在22~42日龄阶段,与对照组相比,低湿组肉鸡ADFI和ADG显著降低(P0.05);高湿组ADFI显著降低(P0.05)。1~42日龄,与对照组相比,低湿组ADFI和ADG显著降低(P0.05),F/G增加(P0.05);高湿组ADFI和ADG降低,F/G提高,但差异不显著(P0.05)。与对照组相比,高湿组42日龄肉鸡屠宰率显著降低(P0.05),21日龄肉鸡胸肌的蒸煮损失显著提高(P0.05),21日龄肉鸡胸肌的剪切力显著降低(P0.05);低湿组42日龄肉鸡胸肌的黄度值(b*)值显著提高(P0.05)。【结论】低湿或高湿均不利于肉鸡生长,其中低湿可显著降低肉鸡平均日增重和饲料转化率,而高湿则显著影响肉鸡的屠宰性能及肉品质。     

日粮中添加益生菌和植物多糖对圈养山羊血清抗氧化指标及肉品质的影响

【目的】为了研究益生菌和植物多糖对圈养山羊抗氧化性能和肉品质的影响。【方法】选取40头4月龄健康母羔羊,随机分为4组,每组10头羊,分别为对照组、益生菌组、植物多糖组和复合组(益生菌+植物多糖)。试验期为期70 d,其中预试期10 d,正试期60 d。【结果】与对照组相比,在正试期的第60天,益生菌组和植物多糖组的血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化酶(GSH-Px)显著升高(P0.05),丙二醛(MDA)含量显著降低(P0.05),复合组血清的GSH-Px含量显著升高(P0.05)。益生菌组、植物多糖组和复合组的肌肉滴水损失均显著低于对照组,但益生菌组和植物多糖组的肌肉水分含量比对照组显著升高(P0.05),肉色b*值显著低于对照组(P0.05)。【结论】饲料中添加益生菌、植物多糖可提高圈养山羊的抗氧化功能、改善宰后羊肉品质。     

酒糟对氧化应激肉鸡肉品质和抗氧化能力的影响

为研究玉米酒糟及其可溶物(Distillers dried grains with solubles,DDGS)对地塞米松(Dexamethasone,DEX)诱导的应激肉鸡肉品质和抗氧化能力的影响。选用300只1日龄科宝500肉鸡,随机分为对照组和试验组,每处理6个重复,每重复25只肉鸡,其中,对照组饲喂基础日粮,试验组饲喂150g/kg DDGS日粮。22日龄时,再分为4个处理。处理1:饲喂基础日粮,第23天开始注射生理盐水;处理2:饲喂基础日粮,第23天开始注射DEX;处理3:饲喂150g/kg DDGS日粮,第23天开始注射生理盐水;处理4:饲喂150g/kg DDGS日粮,第23天开始注射DEX。DEX均为腹腔隔日注射3次,剂量为3mg/kg。结果表明,注射期DEX显著提高肉鸡腹脂率、肝脏指数、胸肌L*值及血清GSH-Px活性(P0.05);降低血清T-AOC活性和MDA浓度(P0.05)。DDGS显著增加胸肌失水率和L*值(P0.05),降低血清T-AOC活性(P0.05)。应激后,DEX显著提高肉鸡腹脂率并降低血清GSH-Px和T-AOC活性(P0.05)。DDGS组肉鸡血清T-AOC活性显著降低(P0.05)。结果提示,DEX成功诱导肉鸡氧化应激,日粮中添加DDGS未显著改善应激肉鸡肉品质。     

不同氨气浓度对肉鸡生长性能及肉质性状的影响

【目的】氨气是鸡舍中产生的有害气体之一,探讨不同氨气浓度对肉鸡生长性能及肉质性状的影响。【方法】试验在动物营养学国家重点实验室昌平基地的呼吸舱中进行。选择21日龄健康、体重相近(743.6±8.2) g的AA肉公鸡320只,随机分于4个呼吸舱中饲养,一个舱为一个处理,每个处理设4个组内重复,每个重复20只鸡。对照组氨气浓度控制在（3±3）µL·L^-1,3个试验组氨气浓度分别控制在（25±3）、（50±3）、（75±3）µL·L^-1。网上平养,自由采食和饮水。42日龄时试验结束,试验期间记录肉鸡的日采食量和健康状况,分别于肉鸡32日龄和42日龄时按重复称重,计算肉鸡的日增重及饲料转化率,并从每个重复中随机选取3只肉鸡屠宰取样,测定其屠宰性能和肉质性状。【结果】1)在22-32日龄期间,肉鸡的平均日增重和平均日采食量随着氨气浓度的升高呈线性降低(P＜0.05);当氨气浓度达到50、75µL·L^-1时,肉鸡的平均日增重和平均日采食量显著低于对照组(P＜0.05);氨气浓度对耗料增重比的影响未达显著水平(P＞0.05);在此期间,各处理肉鸡的屠宰率、全净膛率、半净膛率等没有表现出显著差异(P＞0.05)。2)在33-42日龄期间,肉鸡的平均日采食量也随着氨气的浓度升高呈线性降低(P＜0.05);与对照组相比,3个试验组肉鸡的平均日采食量都显著降低(P＜0.05);氨气浓度对肉鸡平均日增重和耗料增重比的影响未达显著水平(P＞0.05)。3)在整个试验期内（22-42日龄）,肉鸡的平均日增重和平均日采食量随着氨气的浓度升高呈线性降低(P＜0.05);与对照组相比,3个试验组肉鸡的平均日采食量和平均日增重都显著降低(P＜0.05),而耗料增重比显著提高(P＜0.05);随着氨气浓度升高,肉鸡腹脂率有升高的趋势,其中75µL·L^-1氨气处理的肉鸡腹脂率显著高于对照组肉鸡的腹脂率(P＜0.05)。在整个试验期内,氨气浓度对肉鸡胸肌pH(24 h后)、肉色的影响都未达显著水平(P＞0.05),但对胸肌的滴水损失产生了明显的影响,与对照组相比,3个试验组肉鸡胸肌的滴水损失都显著升高(P＜0.05)。【结论】鸡舍内氨气浓度达到25µL·L^-1时即会影响肉鸡的生长性能及肉质性状,且随着氨气浓度的增加,这种影响加剧,暴露在高浓度氨气中的肉鸡,其腹脂率、胸肌滴水损失率增加。建议鸡舍内氨气浓度应控制在25µL·L^-1以内。     

Effect of breed, sex and birth parity on growth, carcass and meat quality in pigs

The effects of breed, sex and birth parity on the traits of growth, carcass and meat quality were investigated in three different breeds including Swedish Landrace, British Large White and an indigenous Chinese breed — Tongcheng pigs. The results indicated that the Swedish Landrace and the British Large White had advantages over the Tongcheng pigs in growth rate, feed conversion rate (FCR) and carcass traits, but had disadvantages in meat quality. In contrast to the British Large White, the Swedish Landrace had higher average daily gain during the trial (ADG2) (877.04 g·day⁻¹ vs. 813.95 g·day⁻¹, P < 0.05), and marbling score (MS) (2.48 vs. 2.02, P < 0.01), larger eye muscle area (EMA) (41.80 cm² vs. 35.14 cm, P < 0.01) and more efficient feed conversion rate (FCR) (3.06 vs. 3.29, P < 0.05), lower muscle shear force (MSF) (4.20 kgf (1 kgf = 9.80665 N) vs. 4.93 kgf, P < 0.05) and backfat thickness (BF) (all P < 0.01) including live backfat thickness (LBF), average backfat thickness at 3 points in the carcass (ABF), backfat thickness between 6th and 7th ribs (6–7 th BF) and backfat thickness at 10th rib (10 th BF). There was a difference (P < 0.05) only inMS between castrated females (CF) and castrated males (CM). Birth parity affected ADG2 (P < 0.05), some carcass characteristics and meat quality, including CL₁ (P < 0.001), CL₂ (P < 0.05), BF (ABF, 6–7th BF and 10th BF, all P < 0.001), EMD (P, 0.001), EMA (P < 0.001), percentage of leaf and caul fat (PLC) (P < 0.05), proportion of lean and bone of the ham (PLBH) (P < 0.05), muscle drip loss percentage (DL) (P < 0.05) and intramuscular fat content (IMF) (P < 0.05). The breed-sex interaction only impacted the average daily gain from birth to marketing (ADG1) and DL (both P < 0.05). However, there was no significant effect of sex-parity interaction on all the traits tested.     

Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings' corticosterone metabolites of broilers

The present study aimed to investigate the effect of relative humidity(RH) at either acute or chronic moderate ambient temperature(Ta) on growth performance and droppings' corticosterone metabolites of broilers.Two experiments were conducted: effect of RH(35,60 or 85%) on average daily feed intake(ADFI) and droppings' corticosterone metabolites at acute(1 d: 20–26 or 31–20°C,26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta(experiment 1) and effect of RH(35,60 or 85%) on growth performance and droppings' corticosterone metabolites at chronic(step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta(experiment 2).Droppings were collected at the 2,4,6,8,and 22 h after Ta-RH controlled in experiment 1 and at the 2,4,6,and 22 h after Ta controlled to 32°C in experiment 2.The results showed that: 1) In experiment 1,85% RH increased(P0.05) the droppings' corticosterone metabolites at the 2,6,8,and 22 h and 35% RH increased(P0.05) it at the 2 and 22 h compared to the 60% RH.Moreover,85% RH further increased(P0.05) it compared to the 35% RH,however,no difference(P0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased(P0.05) droppings' corticosterone metabolites at the 2,6,8 and 22 h and decreased(P0.05) ADFI compared to the 60% RH,moreover,85% RH further increased(P0.05) droppings' corticosterone metabolites and further decreased(P0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings' corticosterone metabolites in the whole period had a negative correlation(P0.02) with the ADFI.2) In experiment 2,85% RH increased(P0.01) droppings' corticosterone metabolites only at the 2 h and decreased(P0.02) ADFI and average daily gain(ADG) compared to the 60% RH,no difference(P0.05) in droppings' corticosterone metabolites was found between the 35 and 60% RH,however,35% RH decreased(P0.01) ADG compared to the 60% RH,and the average of droppings' corticosterone metabolites in the whole period also had a negative correlation(P0.02) with ADFI and ADG.In conclusion,droppings' corticosterone metabolites could be used as a RH stress index and low and high RH,especially high RH,reduced growth performance possibly through inducing RH stress at moderate temperature.     

21～42日龄肉鸡能量和蛋白质需要量的研究

以商品代艾维茵肉鸡为供试动物,设置3个日粮代谢能(ME)水平,分别为12.55、12.97和13.38 MJ/kg;4个粗蛋白(CP)水平,分别为18.5%、19.0%、19.5%和20.0%.采用3×4因子设计进行饲养试验, 研究日粮ME和CP水平对22～42日龄肉鸡生产性能、胴体性能以及肉品质的影响.结果表明:(1)日粮ME水平对22～42日龄肉鸡的日均采食量、平均日增体质量、料重比和21日体质量影响极显著(P<0.01);日粮CP水平对22～42日龄肉鸡的日均采食量影响不显著(P>0.05),但对平均日增体质量、42日体质量和料重比影响极显著(P<0.01).日粮ME和CP的互作对22～42日龄肉鸡料重比影响极显著(P<0.01);较高的日粮ME水平和CP水平可获得理想的生产性能;(2)日粮ME水平对22～42日龄肉鸡半净膛率、腿肌率和腹脂率影响极显著(P<0.01),对屠宰率影响显著(P<0.05),对全净膛率和胸肌率影响都不显著(P>0.05);日粮CP水平与22～42日龄肉鸡的胸肌率呈正相关,对其他胴体性能指标影响不显著(P>0.05);(3)随日粮ME水平增加,腿肌的红度(a*)先降低后增加,但对胸肌红度(a*)影响不显著(P>0.05);胸肌和腿肌的黄色度值(b*)都与日粮ME和CP水平呈正相关;日粮ME水平对胸肌的亮度(L*)影响不显著(P>0.05);(4)胸肌的PH值与日粮ME水平呈负相关,腿肌的pH值随日粮CP水平的升高呈先上升后下降趋势;腿肌的持水率与日粮ME水平呈正相关.通过本试验并结合生产实际认为: 22～42日龄肉鸡适宜的ME水平为12.97MJ/kg,CP水平为19.0%～20.0%之间.     

母猪饲粮添加脯氨酸对哺乳环江香猪血浆生化参数和氨基酸含量的影响

【目的】旨在研究母猪饲粮添加脯氨酸对哺乳环江香猪血浆生化参数和氨基酸含量的影响。【方法】选取15头配种后第16天的环江香猪,随机分成3组,每组5个重复(栏),每个重复1头猪。分别饲喂添加w为0.77%L–丙氨酸(等氮对照组)、w为1.00%L–脯氨酸(脯氨酸组)、w为0.77%L–丙氨酸+w为0.0167%二氟甲基鸟氨酸(DFMO组)的试验饲粮。于产后第7和第14天,每窝称体质量后随机选取1头哺乳仔猪,测定血浆生化参数和游离氨基酸含量。【结果】7日龄时,脯氨酸组和DFMO组血氨浓度显著低于等氮对照组(P0.05)。14日龄时,脯氨酸组仔猪体质量显著高于等氮对照组和DFMO组(P0.05),血氨浓度和胆碱酯酶活性显著高于DFMO组(P0.05),而肌酸激酶活性显著低于DFMO组(P0.05),血浆葡萄糖和脯氨酸浓度显著高于等氮对照组(P0.05);脯氨酸组和DFMO组血浆精氨酸浓度显著高于等氮对照组(P0.05);等氮对照组和脯氨酸组血浆天冬酰胺浓度显著低于DFMO组(P0.05);DFMO组血浆鸟氨酸浓度显著高于等氮对照组(P0.05)。【结论】母猪饲粮添加脯氨酸可通过影响哺乳仔猪葡萄糖和氨基酸代谢而促进其生长发育。     

Effect of a Chinese herbal formula Astragalus immunomodulator on immune function of chickens

In order to investigate the immunomodulatory effects and the mechanism of a Chinese herbal medicine, Zengmiansan (Astragalus immunomodulator), on immune function of chickens, three hundred 1-day-old chickens were assigned randomly into 5 groups, i.e., the blank control group, the Chinese herbal medicine Zengmiansan (ZMS)-treated group, the cyclophosphamide group, the cyclophosphamide plus levamisole group, the cyclophosphamide plus ZMS group and the control group. All chickens were immunized with Lasota vaccine by nosedrip or eye-drop at the age of 6 days. Newcastle Disease (ND) antibody titers, growth indexes of the spleen, thymus and bursa of Fabricius, the concentrations of CD₄ ⁺ lymphocytes and CD₈ ⁺ lymphocytes in spleen, thymus and peripheral blood, and the apoptosis of splenocytes, thymocytes and bursa of Fabricius cells were observed at the ages of 14, 21, 28 and 35 days, respectively. Our results indicated that the NDV antibody titers of chickens in the Chinese herbal medicine ZMS-treated group at the ages of 14 and 21 days were significantly higher than that of the other groups (P<0.01). The growth indexes of immune organs, the concentrations of CD₄ ⁺ lymphocytes and the ratio of CD₄ ⁺/CD₈ ⁺ T lymphocytes of chickens in the Chinese herbal medicine ZMS- treated group at the ages of 14, 21 and 28 d were significantly higher than those of the other groups (P<0.01). The apoptotic splenocytes, thymocytes and bursa of Fabricius cells of chickens in the ZMS-treated group were significantly lower than the other groups (P<0.01) at the ages of 14, 21 and 28 days.     

锡林郭勒草原放牧蒙古牛肉质特性研究

为研究锡林郭勒草原蒙古牛肌肉肉质特性,选择内蒙古锡林郭勒草原全年放牧蒙古牛和西门塔尔牛各8头,屠宰后采集背最长肌肌肉进行肉品质及矿物质含量分析。结果表明:1)蒙古牛肌肉中的肌肉红度a~*、黄度b~*、系水率、熟肉率、剪切力、干物质、灰分显著高于西门塔尔牛(P0.05),而失水率、pH显著低于西门塔尔牛(P0.05),肉中亮度、粗蛋白质和粗脂肪虽然高于西门塔尔牛,但差异不显著(P0.05)。2)蒙古牛矿物质元素Ca、P、Cr、Cu、Fe、Mn、Zn、Se含量显著高于西门塔尔牛(P0.05),Mg、K含量显著低于西门塔尔牛(P0.05),虽然Mo含量蒙古牛高于西门塔尔牛,但差异不显著(P0.05)。综上,蒙古牛肌肉肉质特性比西门塔尔牛好,肉中所含矿物质大多比西门塔尔牛高,所以具有更好的食用、加工潜力。     

Effects of Chinese herbal formula Heat-stress-releasing on antioxidant function in dairy cows

In order to investigate the effects of a Chinese herbal formula Heat-stress-releasing on the antioxidant function in dairy cows, ten dairy cows were randomly divided into the control group and the experimental group, with five cows in each group. All the cows were fed with a basal diet. The animals in the experimental group were given with 220 g of herbs per day in addition to the basal diet. The trial was conducted for 14 days. Blood samples were taken from the vena cava at day 0, day 7, and day 15, respectively. The antioxidant statuses were examined. The results are as follows. (1) Heat-Stress-releasing formula can significantly increase the milk yield of dairy cows under heat stress. Compared with the control group, the milk yield of the herb-treated group increased by 14.01% (P<0.05), 14.32% (P<0.05) and 15.01% (P<0.05) in prophase, metaphase and anaphase of the test, respectively. (2) Heat-Stress-releasing formula can increase significantly the antioxidant status of the heat stressed dairy cows. Compared with the control group, the superoxide dismutase (SOD) activity increased by 45.93% (P<0.01) at day 7 and by 54.40% (P<0.01) at day 15. The Glutathioneperoxidase (GSH-PX) activity of the test group increased by 17.99% (P<0.05) at day 7 and 25.98% (P<0.01) at day 15. The total antioxidant capacity (T-AOC) of the test group increased by 43.64% (P<0.01) at day 7 and 46.35% (P<0.01) at day 15. The malondaldehyd (MDA) content of test group declined by 23.88% (P<0.01) at day 7 and 25.32% (P<0.01) at day 15.