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1.
为比较研究对亚急性瘤胃酸中毒(SARA)耐受性不同的奶牛血浆和乳中代谢组的差异,试验选用12头装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛[泌乳天数=(114±22) d],饲喂精粗比为4∶6的全混合日粮。在试验期第20和21天晨饲后0、2、4、6、8和12 h监测瘤胃pH值,在早晚饲喂前收集奶样,晨饲6 h后采集颈静脉血,用于测定脂肪酸及代谢物组成。基于奶牛瘤胃平均pH值高低,将奶牛分为SARA易感组(SUS,瘤胃pH=5.76,n=4)和SARA耐受组(TOL,瘤胃pH=6.10,n=4)。脂肪酸测定结果分析显示,与TOL组相比,SUS组奶牛血液及乳中的碳链长度≤C16的脂肪酸含量显著增高(P<0.05),而>C16的脂肪酸的含量显著降低(P<0.05),乳中饱和脂肪酸及单不饱和脂肪酸含量均显著降低(P<0.05)。血浆代谢组结果显示, SUS组奶牛血浆中L-苯丙酮酸水平显著降低(P<0.05),而MG(18:0/0:0/0:0)、9-HODE、12(13) Ep-9-KODE、烟酰胺、异戊基肉碱、磷酸肌酸和L-谷氨酸水平显著升高(P<0.05)。乳代谢组分析结果显示,与TOL组比较,SUS组奶牛乳中的1-硬脂酰磷酸甘油丝氨酸和鞘氨醇水平显著升高(P<0.05),而甘油磷酰基乙醇胺、3-磷酸甘油和乳清酸等其他14个差异代谢物水平显著降低(P<0.05),这些差异代谢物主要涉及甘油磷脂代谢、甘油脂代谢及泛酸与辅酶A代谢等代谢途径。综上所述,SARA耐受性不同的奶牛的血浆和乳中脂肪酸及代谢物组成存在较大差异,SUS组奶牛血浆中氨基酸代谢活动增加,乳腺的乳脂从头合成能力较强,而从血液中摄取长链脂肪酸能力减弱,与此同时,易感奶牛乳中磷脂、乳清酸等营养物质水平下降,乳品质下降。  相似文献   

2.
旨在探究一株酿酒酵母和两株瘤胃源褶皱假丝酵母对亚急性瘤胃酸中毒(subacute ruminal acidosis,SARA)绵羊的缓解作用及其机制,为研制防治SARA微生态制剂提供优良菌株和理论依据。选取60只2月龄同期断奶的杜泊羊(♂)×湖羊(♀)F1代作为试验动物。通过逐步递增饲粮精粗比成功诱导40只绵羊发生SARA,将SARA绵羊随机分为4组,每组10只,分别为:SARA组、酿酒酵母组(Saccharomyces cerevisiae,SC)、褶皱假丝酵母一组(Diutina rugosa 1,DR1)、褶皱假丝酵母二组(Diutina rugosa 2,DR2),各组均饲喂精粗比为90∶10的日粮,酵母组于每天晨饲后分别灌服100 mL酿酒酵母ACCC 21162、褶皱假丝酵母N09、褶皱假丝酵母N07。对照组(Control,CON)饲喂50∶50饲粮。分别于第1、3、7、10天测定各组瘤胃液pH,第10天测定瘤胃与血液异常代谢产物、血气指标、瘤胃菌群。结果显示:1)灌服酵母组第3天后瘤胃液pH显著高于SARA组(P<0.05),灌服酵母可使SARA得有效缓解。2)瘤胃菌群相对丰度发生变化,SC组最优菌属为乳杆菌属,CON组最优菌属为普雷沃氏菌科未确定菌属,SARA、DR1、DR2组最优菌属为瘤胃菌科未确定属;灌服酵母组中,SC组丰富度指数最高,DR2组多样性指数最高。3)灌服酵母组瘤胃液和血液乳酸、瘤胃液组胺显著低于SARA组(P<0.05)。4)SC、DR2组血液pH、全血碱剩余极显著高于SARA组(P<0.01),灌服酵母组血液二氧化碳分压、二氧化碳总量、实际碳酸氢盐显著高于SARA组(P<0.05)。5)瘤胃液pH与血液实际碳酸氢盐呈现显著正相关(P<0.05),瘤胃液乳酸与瘤胃菌群Chao 1指标呈现显著负相关(P<0.05)。结果提示,3株酵母均可提升瘤胃菌群丰富度、降低瘤胃液和血液乳酸、减轻瘤胃炎症、缓解机体酸中毒。  相似文献   

3.
选择7只装有永久性瘤胃瘘管的泌乳中期山羊,2×2拉丁方设计,分别饲喂精粗比为6∶4和4∶6的饲料,通过饲喂精粗比6∶4饲料建立泌乳期山羊瘤胃亚急性酸中毒(subacute ruminal acidosis, SARA)模型,研究SARA时山羊血液和瘤胃液中皮质醇浓度、肝脏皮质醇受体(glucocorticoid receptor, GR)mRNA表达及其他相关指标的变化。结果表明,精粗比6∶4日粮饲喂2周后成功诱导SARA状态(SARA组),采食后瘤胃液pH值低于5.8持续时间约6 h,而精粗比为4∶6组山羊瘤胃液pH均高于6.0 (对照组)。高精料日粮处理对瘤胃pH和乳酸以及瘤胃液和血浆内的脂多糖、皮质醇浓度有显著性影响(P<0.05),采食前SARA组山羊瘤胃液中乳酸浓度显著高于对照组(P<0.05),采食后0~4 h乳酸含量下降,6~10 h时逐渐增加并极显著高于对照组(P<0.01);2组间瘤胃液中脂多糖浓度无显著性差异(P>0.05),SARA组血浆脂多糖浓度在采食前和采食后6 h均显著高于对照组(P<0.05);采食前SARA组山羊血液中皮质醇浓度高于对照组(P=0.05),但采食后6 h两组间无显著差异(P>0.05); 2组山羊瘤胃液中皮质醇浓度在采食后2,4和6 h分别显著高于对照组(P<0.05),但在采食前和采食后10 h无显著差异(P>0.05)。Real-time PCR结果显示,SARA组山羊肝脏中GR mRNA表达显著下调(P<0.05)。本研究结果显示,泌乳期山羊发生SARA时糖皮质激素水平升高,负反馈下调肝脏GR的表达水平,提示SARA时机体处于应激状态,可能引起肝脏的物质代谢和营养物质重分配的改变。  相似文献   

4.
本试验旨在研究产前运动对围产期奶牛生理代谢指标的影响,为围产期奶牛健康管理提供科学指导和理论依据。试验选取年龄相似,体况评分、胎次和预产期相近的经产荷斯坦奶牛24头,随机分为试验组(TRT组)和对照组(CON组),每组12头,统一饲养管理。于预产期前21 d开始,TRT组奶牛每日09:00和16:00以<3 km/h的速度运动1 h,每头奶牛每日总运动量为(4.0±0.2) km/d;CON组自由活动。分别在预产期前21、7 d、分娩当天及产后7、30 d (分别记为-21、-7、0、+7和+30 d),于晨饲前采集血液,测定血浆中非酯化脂肪酸(NEFA)、β-羟基丁酸(BHBA)、葡萄糖(GLU)、甘油三酯(TG)、胆固醇(CHOL)、肌酐(CREA)及尿素(UREA)浓度。结果显示,试验期间,TRT组血浆NEFA、BHBA浓度与CON组相比均呈下降趋势(0.05<P<0.1),-7 d时TRT组NEFA浓度显著低于CON组(P<0.05);TRT组血浆GLU浓度变化较CON组平稳,在+30 d极显著高于CON组(P<0.01);两组血浆TG浓度均在分娩当天急剧下降,产前血浆TG浓度均极显著高于分娩后各时间点(P<0.01),+30 d时TRT组极显著高于CON组(P<0.01);血浆UREA、CREA浓度在两组间无显著差异(P>0.05)。综上,以<3 km/h的速度进行运动(4.0 km/d±0.2 km/d),可有效降低围产期奶牛血浆NEFA和BHBA浓度,缓解能量负平衡(NEB)压力。  相似文献   

5.
本试验旨在探究SARA(亚急性瘤胃酸中毒)耐受性不同奶牛的瘤胃上皮形态及其功能差异。选取12头装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛,饲喂精粗比为4∶6的日粮,并根据瘤胃pH值的高低,分为SARA易感组(SUS,n=4)和SARA耐受组(TOL,n=4)。瘤胃上皮形态及功能分析结果显示,与TOL组比较,SUS组奶牛瘤胃上皮的棘突层和基底层厚度明显增厚(P<0.05),SUS组奶牛瘤胃上皮组织中参与挥发性脂肪酸(VFA)吸收的PAT1、MCT4和DRA基因表达量较TOL组显著下调(P<0.05),而H+转运载体NHE1、NHE2、NHE3和调节胞内pH的vH+ATPase和Na+/K+ATPase的表达量显著升高(P<0.05);对参与调控瘤胃VFA代谢的基因定量结果表明,SUS组PDHA1和SREBP2的表达量显著高于TOL组(P<0.05),而HMGCL-2的表达量显著降低(P<0.05);此外,SUS组CDK2、CDK6和Cyclin D1、Bad及Caspase-9等参与瘤胃上皮细胞增殖与凋亡的基因表达量显著高于TOL组(P<0.05)。结果说...  相似文献   

6.
罗芳  陶金忠 《畜牧兽医学报》2021,52(11):3118-3125
旨在筛选人工授精后第17天奶牛在不同妊娠状态时的候选生物标志物。本研究以宁夏某奶牛场体重为(550±50) kg,体况评分相近的经产(2~3胎次)健康荷斯坦奶牛为试验对象。同期发情后,在人工授精后第17天晨饲前对奶牛进行尾静脉采血,后期采用计步器和B超仪诊断出奶牛的妊娠状态。根据诊断结果将奶牛分为妊娠组(A组,n=12)和未妊娠返情组(B组,n=24),将这两组血样进行代谢轮廓及代谢物变化分析。主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)结果显示,A、B两组血浆代谢轮廓均发生了明显变化,A、B两组之间共检测出8种ROC (Receiver operating characteristic curve)曲线下面积(area under the ROC curve,AUC)>0.8的差异代谢物。丙氨酸-亮氨酸、甘氨酸、脯氨酸、L-正亮氨酸、DL-苯丙氨酸、肌氨酸、吡咯-2-羧酸和缬氨酸-蛋氨酸有望成为识别妊娠组(A组)和未妊娠返情组(B组)的差异代谢物。综上表明,血浆中的这8种代谢物有望成为奶牛妊娠识别阶段潜在的生物标志物,为配种早期妊娠识别提供新思路。  相似文献   

7.
旨在应用代谢组学技术筛选产后卵巢静止奶牛血浆中差异代谢物,探究差异代谢物与奶牛卵巢静止的关系。试验选取了产后45~60 d卵巢静止奶牛和正常发情奶牛各15头,应用LC/MS技术检测两组奶牛血浆样品,运用多元统计分析与单变量分析,结合生物信息学分析,筛选出血浆差异代谢物,揭示不同代谢通路中的差异代谢物与奶牛卵巢静止的关系。结果显示:LC/MS分析共筛选出14种血浆差异代谢物。与发情组奶牛相比,卵巢静止组奶牛有11种差异代谢物明显升高:分别是D-塔格糖、L-亮氨酰-L-脯氨酸、L-鹅肌肽、脯氨酸-缬氨酸、赖氨酸-亮氨酸、N-(3-苯基丙酰基)甘氨酸、7-烯胆(甾)烷醇、γ-生育酚、β-隐黄素、视黄醛和鞘磷脂;3种差异代谢物降低:分别是胞嘧啶、1-棕榈酰溶血磷脂酰胆碱和1-硬脂酰-SN-甘油-3-磷酰胆碱。代谢通路分析代谢组学所获得的奶牛卵巢静止血浆差异代谢物,提示奶牛产后糖代谢、脂类代谢、氨基酸代谢和谷胱甘肽代谢等的异常会阻碍卵泡发育,从而导致奶牛产后发生卵巢静止。本试验获得了卵巢静止奶牛血浆差异代谢物,探究了奶牛产后卵巢静止发生中差异代谢物在糖代谢、脂代谢和氨基酸代谢以及其他代谢的变化,为今后深入研究奶牛卵巢静止的发病机理及防治新策略提供了方向。  相似文献   

8.
本试验旨在研究单一和混合油脂日粮对肉鸡生长性能和胸肌脂肪酸组成的影响,并利用代谢组学技术探究日粮油脂干预后胸肌脂肪酸组成发生变化的代谢机制,为调控肉鸡脂肪酸组成的研究提供新思路。选取1日龄慢速型清远麻母鸡480只,随机分为2组(每组6个重复,每个重复40只),对照组(CON)饲喂大豆油日粮,试验组(BOF)饲喂等量的混合油脂(大豆油∶猪油∶鱼油∶椰子油=1.0∶1.0∶0.5∶0.5)日粮,试验期127 d。结果表明,与对照组相比,混合油脂日粮对肉鸡平均日增重没有显著影响(P > 0.05),但显著降低了肉鸡的平均日采食量和料重比(P < 0.05);显著增加了肉鸡胸肌中月桂酸(C12∶0)、肉豆蔻酸(C14∶0)、油酸(C18∶1n-9)、二十碳五烯酸(EPA,C20∶5n-3)和二十二碳六烯酸(DHA,C22∶6n-3)的比例,显著降低了亚油酸(C18∶2n-6)比例(P < 0.05)。利用液相色谱-质谱联用(LC-MS)技术,在试验鸡胸肌中共筛选到110种差异代谢物(变量权重值(VIP) > 1,P < 0.05),其中63种差异物质被注释,主要是磷脂代谢物,包括磷脂酰胆碱(PC)、磷脂酰丝氨酸(PS)和磷脂酰乙醇胺(PE)等。此外,与对照组相比,混合油脂组显著增加了胸肌中谷胱甘肽和肌肽含量(P < 0.05)。代谢通路富集分析表明,α-亚麻酸代谢、花生四烯酸代谢、亚油酸代谢和甘油磷酸代谢等脂质代谢通路发生显著改变(P < 0.05)。综上,混合油脂日粮相较于大豆油日粮提高了肉鸡的饲料转化效率,促进了胸肌组织中DHA和EPA的沉积;日粮油脂干预后肉鸡胸肌中磷脂代谢物、氧化稳定性代谢物和脂类代谢途径发生显著改变。本研究鉴定出的差异代谢物和差异代谢通路可为调控肉鸡脂肪酸组成的研究提供参考。  相似文献   

9.
【目的】 本试验旨在研究饲粮中添加缓释尿素(SRU)和过瘤胃葡萄糖(RPG)对热应激绵羊生产性能和瘤胃发酵功能的影响。【方法】 选取40只健康、体重相近的3月龄湖羊公羔,按初始体重随机分成4个处理组(n=10),分别为对照组(CON组,饲喂基础饲粮)、缓释尿素组(SRU组,基础饲粮中添加缓释尿素15 g/d)、过瘤胃葡萄糖组(RPG组,基础饲粮中添加过瘤胃葡萄糖10 g/d)和联合添加组(UG组,基础饲粮中添加缓释尿素15 g/d+过瘤胃葡萄糖10 g/d),预饲期15 d,正饲期50 d。在正饲期的最后一天晨饲前,分别采集血液和瘤胃液,测定血样中免疫球蛋白A (IgA)、免疫球蛋白M (IgM)、免疫球蛋白G (IgG)、肿瘤坏死因子-α(TNF-α)、白细胞介素-2(IL-2)的含量,并测定瘤胃液pH、氨态氮、微生物蛋白及挥发性脂肪酸等指标。【结果】 与CON组相比,①饲粮中添加缓释尿素、过瘤胃葡萄糖均显著降低热应激绵羊的呼吸频率(P<0.05),UG组热应激绵羊的直肠温度显著降低(P<0.05)。②SRU组、RPG组、UG组热应激绵羊的终末体重和平均日增重均显著提高(P<0.05),料重比显著降低(P<0.05)。③RPG组和UG组热应激绵羊血清中IgG和IgM的含量均显著提高(P<0.05),血清中TNF-α和IL-2的含量显著降低(P<0.05)。④各处理组热应激绵羊瘤胃内乙酸与丙酸的比值均显著提高(P<0.05),SRU组瘤胃内乙酸、异丁酸、异戊酸比例和总挥发性脂肪酸的浓度均显著提高(P<0.05),RPG组瘤胃液pH和异戊酸比例均显著提高(P<0.05),瘤胃内氨态氮、丙酸、丁酸的比例均显著降低(P<0.05),UG组瘤胃内乙酸、总挥发性脂肪酸及微生物蛋白的含量均显著提高(P<0.05)。【结论】 饲粮中添加缓释尿素、过瘤胃葡萄糖显著提高了热应激绵羊的生产性能,改善瘤胃发酵,维持瘤胃内环境的稳定,可有效缓解绵羊热应激。  相似文献   

10.
为探究高加索三叶草(Trifolium ambiguum Bieb.)对不同降温模式低温胁迫的代谢响应机制,本试验对其分别进行缓慢降温(Gradual cooling,GC)和骤然降温(Sudden cooling,SC)处理,利用广泛靶向代谢组学技术检测叶片代谢物,并比较2个处理组与常温对照组(CK)间的代谢物差异。结果表明:在高加索三叶草叶片中共检测出894种代谢物;与CK相比,在GC和SC处理组中分别筛选出124个和139个差异代谢物(Differential metabolites,DMs);2处理组的DMs均主要富集在氨基酸代谢和次生代谢产物的生物合成;紫铆因含量仅在GC组中显著增加(P < 0.05),酪氨酸和新橙皮苷含量仅在SC组中显著增加(P < 0.05);γ-氨基丁酸、亮氨酸、组氨酸、赖氨酸、柠檬酸、矢车菊素和木犀草素含量在2处理组均显著增加(P < 0.05)。这些代谢物含量的增加可能是高加索三叶草适应低温胁迫的主要机制。  相似文献   

11.
在奶牛养殖中,亚急性瘤胃酸中毒(subacute ruminal acidosis,SARA)是一种高发的营养代谢病。随着我国奶牛养殖集约化程度的提高,为提升奶牛生产性能饲喂大量高能谷物饲料极易诱发SARA,导致瘤胃液pH值降低,瘤胃菌群发生改变,瘤胃上皮黏膜层受损,进而影响瘤胃代谢功能。分析了奶牛不同生理阶段、择食行为以及个体差异等SARA的易感因素,探讨了SARA对奶牛瘤胃菌群变化、瘤胃上皮细胞基因表达、瘤胃屏障功能的影响,以期为阐明SARA造成瘤胃功能损伤的机制、降低奶牛发生SARA的风险提供参考。  相似文献   

12.
This study evaluated the effects of dietary concentrate level and chromium methionine(Cr-Met)supplementation on ruminal fermentation and fatty acid composition, and ruminal bacteria abundance in Tan lambs. Forty male Tan lambs [(21.00±1.23) kg body weight, 5 months of age] were randomly assigned to four treatment groups with 10 lambs in each treatment. The treatments were: a low-concentrate (LC) diet (concentrate:forage, 35:65) without Cr-Met supplementation; a high-concentrate (HC) diet (concentrate:forage, 55:45) without Cr-Met supplementation; groups fed the HC diet with 0.75 or 1.50 g·d-1·lamb-1 Cr-Met (HCM and HCH, respectively). Ruminal fluid was collected on day 65 with an oral stomach tube about 3 h after the morning feed and samples used for fermentation analysis, fatty acid composition determination and bacterial DNA extraction. It was found that: 1) Ruminal pH, acetate proportion and acetate:propionate were greater (P<0.05) with the LC diet whereas microbial crude protein, propionate and valerate proportions were greater (P<0.05) with the HC diet. The acetate:propionate was greater (P<0.05) in the HCM group than in the HC group. 2) For the HC diet, the DNA abundances of Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) and Ruminococcus flavefaciens were decreased (P<0.05), compared with the LC diet, whereas the DNA abundance of Anaerovibrio lipolytica was increased (P<0.05). For lambs fed the HC diet, DNA abundances of B. fibrisolvens stearic acid subgroup, Butyrivibrio VA, Butyrivibrio proteoclasticus, and A. lipolytica showed a linear decrease (P<0.05) with increasing Cr-Met supplementation level; However, the DNA abundance of R. flavefaciens showed a linear increase (P<0.05). 3) Compared with the LC group, the concentrations of t11 C18:1, trans C18:1, c9t11 CLA, t10c12 CLA, C18:2n6, and C18:3n3 were decreased by the HC diet without Cr-Met supplementation whereas the concentration of C18:0 was increased. There was a linear increase in t11 C18:1 and trans C18:1 with increasing Cr-Met supplementation level in lambs fed the HC diet. The results suggest that the HC diet inhibited the growth of ruminal bacteria involved in the ruminal biohydrogenation process, and the addition of Cr-Met had a potentially positive effect on conjugated linoleic acid (CLA) synthesis in body tissue. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

13.
本试验旨在探究归芪益母复方制剂对产后奶牛瘤胃微生物和短链脂肪酸的调节作用。将19头待产的健康荷斯坦奶牛随机分为两组,对照组10头,试验组9头。试验组奶牛产后每天灌服归芪益母复方制剂500 mL,对照组奶牛每天灌服等体积饮用水,连续6 d。产后第7天晨饲前采集瘤胃液,采用16S rRNA高通量测序和GC-MS/MS靶向代谢组学技术对两组奶牛瘤胃菌群的丰度和短链脂肪酸的含量进行了测定。结果表明,与对照组相比,试验组奶牛瘤胃变形菌门(Proteobacteria)、Escherichia-Shigella属和拟杆菌属(Bacteroides)的菌群丰度极显著升高(P<0.01),乳杆菌属(Lactobacillus)和Subdoligranulum属菌群丰度显著升高(P<0.05)。试验组奶牛瘤胃丙酸(P<0.05)和异丁酸(P<0.01)含量明显升高。本研究从瘤胃微生物菌群及短链脂肪酸角度揭示了归芪益母方对产后奶牛的保健机制。  相似文献   

14.
The objectives of this study were to 1) determine the variation of nutrient digestion, plasma metabolites and oxidative stress parameters triggered by induced subacute ruminal acidosis (SARA); and 2) evaluate the ability of pelleted beet pulp (BP) as a replacement for ground corn to alleviate SARA. Eight Holstein-Friesian cows were fed four diets during four successive17-day periods: 1) total mixed ration (TMR) containing 0% finely ground wheat (FGW) (W0); 2) TMR containing 10% FGW (W10); 3) TMR containing 20% FGW (W20); and 4) TMR containing 10% BP as a replacement for 10% ground corn (BP10). The SARA induction protocol reduced the mean ruminal pH from 6.37 to 5.94, and the minimum ruminal pH decreased from 5.99 to 5.41 from baseline to challenge period. Mean ruminal pH increased from 5.94 to 6.05, and minimum daily ruminal pH increased from 5.41 to 5.63, when BP was substituted for corn. The apparent digestibility of nutrients was not affected by the dietary treatments, except that the digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) was reduced in cows fed the W20 diet compared with cows fed the W0 and W10 diets, and cows fed the BP10 diet had higher NDF and ADF digestibility than the cows fed the W20 diet. Cows fed the W20 diet had a lower plasma concentration of β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), cholesterol, triglyceride, and total antioxidative capacity (TAC), and a higher plasma concentration of glucose, insulin, malonaldehyde (MDA), super oxygen dehydrogenises (SOD), and glutathione peroxidase (GSH-Px) than cows fed the W0 diet. Substitution of BP for corn increased concentrations of plasma BHBA and TAC, but decreased concentrations of plasma MDA. Our results indicate that reduction of fibre digestion; the concomitant increase of plasma glucose and insulin; the decrease of plasma BHBA, NEFA, cholesterol, and triglyceride; and changes of plasma oxidative stress parameters are highly related to SARA induced by W20 diets. These variables may be alternative candidates for SARA diagnosis. We also suggest that the substitution of BP for corn could reduce the risk of SARA, increase fibre digestion, and improve the antioxidant status in dairy cows.  相似文献   

15.
旨在研究日粮中添加过瘤胃保护烟酸(rumen-protected niacin,RPN)和过瘤胃保护胆碱(rumen-protected choline,RPC)对围产期奶牛泌乳性能和肝脂质代谢的影响,为缓解奶牛脂肪肝提供理论依据.本试验选用24头健康、胎次相近的中国荷斯坦围产期奶牛,根据2×2试验设计分为4组,每组6...  相似文献   

16.
The objective of this study was to determine whether subacute ruminal acidosis (SARA) could be diagnosed by continuous measurements of the reticular pH, as compared with the ruminal pH, using healthy cows fed a control diet and SARA cows fed a rumen acidosis-inducing diet. The reticular and ruminal pH were measured simultaneously by a radio transmission pH measurement system. The mean reticular pH at 1-h intervals decreased gradually from the morning feeding to the next feeding time in both healthy and SARA cows, though the decrease in the ruminal pH was observed to be more drastic as compared with that observed in the reticular pH. The threshold of the 1-h mean pH in the reticulum for a diagnosis of SARA was considered to be 6.3, and a significant positive correlation was observed between the reticular and ruminal pH. No differences in the concentrations of lactic acid, ammonia nitrogen, and volatile fatty acids were noted between the reticular and ruminal fluids in SARA cows. These results demonstrate that the reticular pH can be used to detect SARA in cows, as opposed to using the ruminal pH.  相似文献   

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