酮病复方制剂对奶牛酮病抗氧化性能的影响研究

[目的]研发治疗奶牛酮病的新方法、新药物,从抗氧化性能方面揭示广西大学动物科学技术学院临床实验室自主研发的酮病治疗复方制剂——“酮康”对奶牛酮病的疗效.[方法]2013年6月,采用改良水杨醛比色法检测广西南宁某规模化奶牛场围产期奶牛46头,其中9头为酮病牛,并将其分为治疗组（6头）和阳性对照组（3头）,另从37头中选取6头与治疗组奶牛体况相似、胎次相近、产奶量接近的奶牛作为健康对照组.试验期间,治疗组每天灌服“酮康”400ml,连续治疗5d,阳性对照组、健康对照组均不灌服.分别采血检测试验前后奶牛各抗氧化酶活性（CAT、GPX、MDA、SOD、TAC、VE）.[结果]治疗后治疗组奶牛血酮含量明显降低,血糖明显上升,SOD和GPX的活性明显升高,差异极显著（P＜0.01）.CAT活性明显低于对照组,差异显著（P＜0.01）.MDA含量稍有下降,差异不显著（P＞0.05）,虽稍低于健康对照组和阳性对照组,但差异也不显著（P＞0.05）.VE含量明显低于健康对照组,差异极显著（P＜0.01）,而对照组治疗后VE含量均比治疗前高.治疗组在治疗后TAC和CAT活性均低于阳性对照组,差异极显著（P＜0.01）[结论]“酮康”对降低酮病奶牛的血酮含量、提高血糖含量和改善抗氧化性能的作用明显,效果良好.若不进行治疗和科学的饲养管理,酮病将持续伤害奶牛.     

围产期奶牛脂类代谢病监测指标的研究

对呼和浩特市地区某牛场105头围产期奶牛,采用紫外可见分光光度法进行了血中葡萄糖、谷草转氨酶、游离脂肪酸、胆红素、谷丙转氨酶、甘油三酯、胆固醇、碱性磷酸酶、总蛋白、白蛋白和尿素氮含量的测定,采用梯度稀释法对乳中酮体进行检测。实验结果表明:脂肪肝的发病率为41.9%,酮病的发病率为18.1%,患隐性脂肪肝奶牛占整个患脂肪肝奶牛的24.4%,围产期患酮病奶牛都有不同程度的肝细胞脂肪浸润。脂肪肝病牛葡萄糖含量极显著低于正常值(p<0.01),谷草转氨酶和游离脂肪酸含量极显著高于正常值(p<0.01),血清中胆红素、谷丙转氨酶和甘油三酯的含量极显著高于正常值(p<0.01),胆固醇、碱性磷酸酶、总蛋白和白蛋白的含量极显著低于正常值(p<0.01),而尿素氮差异不显著。酮病奶牛血中葡萄糖、总蛋白、白蛋白、胆固醇和碱性磷酸酶的含量极显著低于正常值(p<0.01),谷草转氨酶、游离脂肪酸、谷丙转氨酶、胆红素和甘油三酯的含量极显著高于正常值(p<0.01),而尿素氮差异不显著。     

酸性尿液的泌乳奶牛血/尿临床病理学变化

探讨泌乳奶牛尿液呈酸性时机体血/尿临床病理学的变化。根据尿液p H将实验奶牛分为极酸组15头,偏酸组9头和中性组22头。并对实验奶牛血尿中7项矿物元素、7项炎性因子、9项能量代谢指标的检测和统计分析。结果显示与中性组相比,极酸组血中K、Cu、GLU含量极显著低于中性组(P0.01),血Mg、尿Mg含量显著低于中性组(P0.05),尿Ca含量、血中LPS、BHBA、NEFA含量显著高于中性组(P0.05),尿中P、BUN含量极显著高于中性组(P0.01);与中性组相比,偏酸组尿Ca、尿P、血BHBA、血NEFA含量极显著高于中性组(P0.01),血中Fe、GLU和SAA及尿Cr含量显著低于中性组(P0.05)。结果表明泌乳奶牛尿液呈酸性时表明机体发生酸碱平衡紊乱,可能会伴发能量负平衡、酮病、炎症和矿物质代谢紊乱等病理状态。     

不同血酮水平下产后奶牛生理机能变化规律研究

[目的]为了研究不同血酮水平对奶牛生理机能的影响.[方法]本试验选择围产后期奶牛20头采集血样,根据血液BHBA值分为4组,每组10份.根据已有的研究表示BHBA值在0～0.4 mmol/L范围内的奶牛为正常组,在0.5～1.4 mmol/L范围内的奶牛为能量负平衡组,在1.5～2.9 mmol/L范围内的奶牛为亚临床型酮病组,大于3 mmol/L奶牛为临床型酮病组.采集各组奶牛血液,制备血浆,采用自动兽用生化分析仪和酶标仪测定奶牛各项生化指标.[结果]血浆中BHBA、AST、GLB、TP、NEFA、TCH、TG的浓度临床型组极显著高于其他组(P<0.01),且部分指标随着酮体值的升高呈现升高趋势;血浆中ALP的浓度正常组极显著低于其他各组(P<0.01);血浆中GGT亚临床组显著高于其他组(P<0.05);血浆中ALB的浓度各组之间差异不显著(P>0.05);血浆中ALT的浓度临床型组极显著低于其他各组(P<0.01);血浆中GLB的浓度临床型组显著高于其他各组(P<0.05);血浆中LDL-C、HDL-C的浓度临床组显著高于其他各组(P<0.05),且随着酮体值的升高呈现升高趋势;血浆ApoA1、ApoB浓度在NEB组显著高于其他各组(P<0.05).[结论]血酮水平可预警奶牛肝脏功能和脂代谢是否异常.     

能量补充剂对酮病奶牛肝脏代谢和肝损伤的影响

将杜仲粉、过瘤胃葡萄糖等12种成分按照一定比例混合后,制成能量补充剂,选择6头围产期健康奶牛与30头围产期酮病奶牛分别进行能量补充剂毒性试验与酮病治疗效果评价试验。结果表明：健康围产期奶牛连续灌服7 d能量补充剂不会对奶牛肝肾功能造成损伤。酮病奶牛连续灌服能量补充剂3 d后,显著降低血液β-羟丁酸、游离脂肪酸浓度,同时显著提高血糖浓度;灌服能量补充剂能显著增加酮病奶牛血液过氧化物酶体标志酶过氧化氢酶以及谷胱甘肽过氧化物酶活性,显著降低氧化应激标志物丙二醛含量;此外,血液炎性细胞因子IL-6、IL-8、肿瘤坏死因子-α含量以及肝损伤指示酶丙氨酸氨基转移酶和天门冬氨酸氨基转移酶的含量及总胆红素和间接胆红素的含量显著降低;灌服能量补充剂能显著促进酮病奶牛肝脏AMPK的磷酸化和SIRT3的蛋白表达。综上,灌服能量补充剂有效缓解酮病的能量负平衡、氧化应激、炎性反应和肝损伤。     

高浓度非酯化脂肪酸诱导Ⅱ型酮病奶牛氧化应激

为探究Ⅱ型酮病奶牛的氧化应激状态及其诱因，采集健康和Ⅱ型酮病奶牛的血液样品，并分析氧化应激和肝损伤相关指标。结果表明：Ⅱ型酮病奶牛血液中NEFA、MDA和H2O2的含量高于健康奶牛，而CAT、SOD和GSH-Px的活性低于健康奶牛；此外，肝损伤的标志物，AST、ALT、GGT和GLDH的活性均高于健康奶牛，说明Ⅱ型酮病表现为氧化应激和肝损伤。体外试验表明，高浓度NEFA(1.2 mmol/L)显著增加奶牛肝细胞中ROS的含量，引起肝细胞氧化应激并释放大量AST和ALT，而添加抗氧化剂NAC可以缓解NEFA引起的肝细胞氧化应激和损伤。这些结果说明高浓度NEFA通过诱导肝细胞氧化应激引起肝损伤，研究有助于明确Ⅱ型酮病的发病机理，为Ⅱ型酮病的防治奠定理论基础。     

酮病对荷斯坦奶牛抗氧化系统和一氧化氮含量的影响

[目的]研究新疆荷斯坦奶牛酮病血清中的部分生化指标的变化及其酮病致病机理的探讨。[方法]以新疆荷斯坦奶牛为试验动物,用酮粉法和改良的水杨醛检测法对其血清进行检测,应用硝酸还原酶法测定血清中一氧化氮(NO)含量和一氧化氮合酶(NOS)活性;应用DTNB显色法测定血清中GSH-Px活力,应用黄嘌呤氧化法测定血清中T-SOD活力,应用硫代巴比妥酸法测定血清中MDA含量。[结果]酮病奶牛血清中GSH-Px活力极显著降低(P0.01),T-SOD活力显著降低(P0.05),血清中MDA含量显著增高(P0.05);对照组奶牛血清中的NO含量和NOS活性均显著高于阳性组。[结论]酮病不但影响奶牛的抗氧化系统而且也会降低一氧化氮含量和一氧化氮酶的活性,对于揭示奶牛酮病的发生机理具有重要意义。     

硫辛酸对围产期奶牛血清脂肪代谢和肝功能酶的影响

目的探讨硫辛酸对围产期奶牛血清脂肪代谢和肝功能酶的影响。方法选择产前约20d的干乳期奶牛48头,分为4组,Ⅰ组为对照组,Ⅱ、Ⅲ、Ⅳ组分别每头补饲硫辛酸3、5、8g·d-1,连续50d,检测血清甘油三酯(TG)、总胆固醇(Chol)、非酯化脂肪酸(NEFA)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)含量及血清碱性磷酸酶(AKP)、γ-谷氨酰转移酶(γ-GT)、乳酸脱氢酶(LDH)、丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)活性。结果第Ⅲ、Ⅳ组血清NEFA含量第20天后低于对照组,第Ⅳ组第30天显著低于对照组(P0.05);试验组血清AST活性第30天后均显著(P0.05)或极显著(P0.01)低于对照组;其它指标各处理组之间无显著差异(P0.05)。结论硫辛酸可改善围产期奶牛的脂肪代谢,有效保护奶牛围产期肝脏功能的损伤。     

不同硒源对羔羊抗氧化能力、细胞因子及T3、T4的影响

健康滩羊羔羊24头,随机分为3组.对照组(C)饲料中添加玉米淀粉,试验组(T1、T2)饲料中分别添加富硒酵母和亚硒酸钠,试验期60 d.分别于试验期30和60 d测定全血中GSH-Px活性、血浆SOD活性、血浆MDA含量、血浆IL-1、IL-2、IL-6、TNF-α水平以及血浆甲状腺激素T3、T4浓度;试验期60 d时测定组织硒含量.结果发现,在30和60 d时,T1和T2组羔羊组织硒含量、全血GSH-Px活性、血浆SOD活性、血浆IL-1、IL-2、IL-6、TNF-α水平以及血浆T3浓度均显著或极显著高于C组(P＜0.01或P＜0.05);血浆MDA含量及T4浓度均显著或极显著低于C组(P＜0.01或P＜0.05).在30 d时,T1组羔羊全血GSH-Px活性及组织硒含量均极显著高于T2组(P＜0.01).在60 d时,T1组羔羊全血GSH-Px活性及组织硒含量均极显著高于T2组(P＜0.01);T1组羔羊血浆MDA含量显著低于T2组(P＜0.05).结果表明,有机硒源提高羔羊机体硒状态以及机体抗氧化能力的效果优于无机硒源,但在提高细胞因子水平和血浆T3浓度以及降低血浆T4浓度方面两者差异不显著.     

不同硒源对羔羊抗氧化能力、细胞因子及T3、T4的影响

健康滩羊羔羊24头,随机分为3组.对照组(C)饲料中添加玉米淀粉,试验组(T1、T2)饲料中分别添加富硒酵母和亚硒酸钠,试验期60 d.分别于试验期30和60 d测定全血中GSH-Px活性、血浆SOD活性、血浆MDA含量、血浆IL-1、IL-2、IL-6、TNF-α水平以及血浆甲状腺激素T3、T4浓度;试验期60 d时测定组织硒含量.结果发现,在30和60 d时,T1和T2组羔羊组织硒含量、全血GSH-Px活性、血浆SOD活性、血浆IL-1、IL-2、IL-6、TNF-α水平以及血浆T3浓度均显著或极显著高于C组(P＜0.01或P＜0.05);血浆MDA含量及T4浓度均显著或极显著低于C组(P＜0.01或P＜0.05).在30 d时,T1组羔羊全血GSH-Px活性及组织硒含量均极显著高于T2组(P＜0.01).在60 d时,T1组羔羊全血GSH-Px活性及组织硒含量均极显著高于T2组(P＜0.01);T1组羔羊血浆MDA含量显著低于T2组(P＜0.05).结果表明,有机硒源提高羔羊机体硒状态以及机体抗氧化能力的效果优于无机硒源,但在提高细胞因子水平和血浆T3浓度以及降低血浆T4浓度方面两者差异不显著.     

基于1H NMR技术的奶牛I型和II型酮病血浆代谢谱分析

【目的】运用代谢组学中¹H NMR技术方法筛选出Ⅰ型酮病、Ⅱ型酮病与健康对照组之间血浆差异性代谢物。【方法】选取产后7—28 d,平均胎次为2—3胎的实验奶牛50头。根据血糖（Glc）、β-羟丁酸（BHBA）和游离脂肪酸（NEFA）的含量与临床发病特点分为Ⅰ型酮病、Ⅱ型酮病与健康对照组,其中Ⅰ型酮病20头,Ⅱ型酮病为20头,健康对照组为10头。当患病牛血中BHBA＞1.20 mmol·L^-1,Glc＜2.50 mmol·L^-1,NEFA＞0.50 mmol·L^-1时,被认为患I型酮病;当患病牛血浆中BHBA＞1.20 mmol·L^-1,Glc＞2.80 mmol·L^-1, NEFA＞0.50 mmol·L^-1时,被认为患II型酮病;当奶牛血中BHBA＜1.00 mmol·L^-1,Glc＞3.75 mmol·L^-1,NEFA＜0.40 mmol·L^-1时,被认为健康对照组。运用代谢组学中¹H NMR技术对实验奶牛的血浆代谢物分析,获得相应的代谢图谱,并结合多元统计分析中的主成分分析（PCA）、正交偏最小二乘判别分析（OPLS-DA）的模式判别,从而寻找潜在的生物标记物。【结果】通过¹H NMR分析,Ⅰ型酮病、Ⅱ型酮病与健康对照的代谢图谱差异明显,3组代谢产物各自聚集,分散区域显著。Ⅱ型酮病与健康对照比较,获得7种血浆差异代谢物,主要为丙氨酸、赖氨酸、β-羟丁酸、丙酮、乳酸等,其中血浆中β-羟丁酸、丙酮、乳酸浓度升高;丙氨酸、赖氨酸、酪氨酸、肌酸浓度呈现下降。Ⅰ型酮病与健康对照组比较,获得19种血浆差异代谢物,主要为酪氨酸、苯丙氨酸、肌酸、β-羟丁酸、丙酮等,其中β-羟丁酸、丙酮浓度升高;酪氨酸、苯丙氨酸、赖氨酸、组氨酸、丙氨酸、肌酸、肌醇、β-葡萄糖、谷氨酰胺、谷氨酸、柠檬酸、α-葡萄糖、甲酸、甘氨酸、O-乙酰葡萄糖胺、磷酸胆碱浓度呈现下降。Ⅰ型酮病与Ⅱ型酮病比较,获得24种血浆差异代谢物,主要为柠檬酸、组氨酸、β-葡萄糖、异亮氨酸、极低密度脂蛋白/低密度脂蛋白等,其中β-羟丁酸、低密度脂蛋白和极低密度脂蛋白、异亮氨酸、缬氨酸、丙酮、亮氨酸、乙酸浓度升高;柠檬酸、酪氨酸、组氨酸、肌醇、谷氨酰胺、β-葡萄糖、苯丙氨酸、谷氨酸、α-葡萄糖、赖氨酸、甲酸、甘氨酸、磷酸胆碱、丙氨酸、O-乙酰葡萄糖胺浓度呈现下降。【结论】¹H NMR技术与多元统计分析的有效结合能够有效的筛选出Ⅰ型酮病、Ⅱ型酮病与健康对照组之间血浆差异性代谢物,为进一步探究奶牛Ⅰ型酮病、Ⅱ型酮病的发病机理和诊断与防治提供了新的方向。     

自拟益气养阴汤联合耳针治疗2型糖尿病胰岛素抵抗的临床观察

目的 观察自拟益气养阴汤联合耳针治疗2型糖尿病胰岛素抵抗临床疗效。方法 选取2型糖尿病胰岛素抵抗患者64例,随机分为观察组（自拟益气养阴汤加耳针埋穴）和对照组（口服二甲双胍片）,各32例。治疗1个疗程（3个月）后观察两组临床疗效、治疗前后空腹血糖（FPG）、餐后2 h血糖（2hPG）、空腹胰岛素（FINS）、胰岛素抵抗指数（HOMA-IR）、总胆固醇（TC）、甘油三酯（TG）、糖化血红蛋白（HbA1c）、高密度脂蛋白-胆固醇（HDL-C）、低密度脂蛋白-胆固醇（LDL-C）。结果 观察组总有效率96.9%,高于对照组的84.4%,差异有统计学意义（P<0.05）。两组治疗后相关指标变化较治疗前比较,差异均有统计学意义（P<0.05或P<0.01）;治疗后观察组FPG、2hPG、FINS、HbA1c、TG、HDL-C、LDL-C与对照组比较,差异均有统计学意义（P<0.05或P<0.01）。结论 自拟益气养阴汤联合耳针可能通过调节糖脂代谢而起到治疗2型糖尿病胰岛素抵抗的作用,且优于单纯应用二甲双胍片组,值得临床推广应用。     

Effect of Hypoglycemia on Performances, Metabolites, and Hormones in Periparturient Dairy Cows

In this research work, 24 multiparous holstein cows were used to evaluate the effect of hypoglycemia on periparturient metabolism and lactation performance. The cows were arranged into two groups of hypoglycemia （L） and normal plasma glucose （N） based on plasma glucose level. The same diets were fed ad libitum from 28 days before expected calving date to 28 days after calving. The parameters relative to energy balance, such as dry matter intake （DMI）, body weight （BW）, milk yield （MY）, and concentrations of plasma glucose, nonesterified fatty acids （NEFA）, β-hydroxybutyric acid （BHBA）, insulin （INS）, glucagons （GLN）, leptin （LP）, neuropeptide Y （NPY） in plasma were measured at regular intervals. Incidence of hypoglycemia was higher prepartum than that of postpartum （88% vs. 50%）, and the recurrence of hypoglycemia was reversed （31% vs. 100%）. Hypoglycemia did not affect feed intake before and after calving. With the increase of postpartum feed intake, incidence of hypoglycemia decreased rapidly, even disappeared at 28 days of postpartum. Hypoglycemia had no impact on prepartum BW, but BW in L group was lower than that of cows in N group at 1 day and 14 days of postpartum （P〈0.05）. Milk yield was not affected by hypoglycemia. Cows in L group had higher plasma NEFA concentration than cows in N group. It reached a peak （1442 μmol L^-1 vs. 1052 μmol L^-1） at day 1 of postpartum （P〈0.05）. Plasma BHBA concentration of cows in L group was higher than that in N group, which reached a peak （2.01 mmol L^-1 vs. 1.34 mmol L^-1） at 14 days of postpartum （P〈0.05）. Plasma concentration of INS and GLN was unaffected by treatment, but postpartum plasma GLN concentration obviously increased, especially in L group. Plasma concentration of LP and NPY before calving was unaffected by treatment, but postpartum LP level in L group was slightly lower than that in N group, and NPY level in L group was significantly higher than that in N group （P〈0.05）. Overall, periparturient dairy cows are easy to develop hypoglycemia, which stimulates lipid metabolism. Adaptive changes of some metabolites and hormones, such as NEFA, BHBA, INS, GLN, LP, NPY are of benefit to increase feed intake and recovery of NEB in periparturient period, but there still are some issues on interaction of those endocrine factors in the energy balance of periparturient cows to be understood further.     

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake,digestibility, plasma metabolites,ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio(F:C) and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement: whole-length forage(WL) with low F:C(50:50); WL with high F:C(65:35); short-length forage(SL) with high F:C(65:35); and SL with low F:C(50:50). Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size(~50% particles 19 mm). Dry matter intake(DMI) and organic matter(OM) intake was increased by increasing both F:C(P0.01) and forage length(FL)(P0.05), while acid detergent fiber(ADF) and neutral detergent fiber(NDF) intakes were only increased by increasing the F:C(P0.01). The digestibility of NDF was increased as the FL increased(P0.01), and it was also affected by interaction between F:C and FL(P0.05). Cholesterol(CHO)(P0.01), leptin(LP)(P0.05), and growth hormone(GH)(P0.01) concentrations in plasma were increased as dietary F:C increased. A significant increase in plasma triglyceride(TG)(P0.01), insulin(INS)(P0.05), and GH(P0.01) levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F:C diets were significantly lower than those in high F:C treatment(P0.05). Increasing the F:C enhanced ruminal acetic acid(P0.05) and acetic acid/propionic acid(P0.01). Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F:C groups(P0.05). Lower fecal scores(higher diarrhea rate) were observed in calves fed with SL hay compared to WL hay(P0.05). Denatured gradient gel electrophoresis(DGGE) bands and richness index(S) were significantly affected by the interaction between F:C and FL(P0.05), under high F:C, band numbers and richness index from WL group were higher than that from SL group(P0.05), whereas there were no differences between WL andSL groups under low F:C(P0.05). Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F:C(65:35) diet is suitable for weaned calves.     

Effects of Bupleurum extract on blood metabolism,antioxidant status and immune function in heat-stressed dairy cows

This experiment was conducted to evaluate the effects of Bupleurum extract(BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg–1 dry matter. Supplementation with BE decreased(P0.05) blood urea nitrogen(BUN) contents and increased blood total protein(TP) and albumin(ALB) levels compared with control cows, but it had no effects(P0.05) on blood glucose(GLU), nonesterified fatty acid(NEFA), total triglyceride(TG), low-density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C). Compared with control cows, cows fed BE had higher(P0.05) superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activity. However, supplementation with BE had no effect(P0.05) on total antioxidant capacity(T-AOC) or malondialdehyde(MDA) levels. The immunoglobulin(Ig) A and G contents increased(P0.05) in cows fed 0.25 or 0.5 g of BE kg–1. Interleukin(IL)-2 and IL-4 levels were higher(P0.05) in cows fed 0.5 and 1.0 g of BE kg–1, and IL-6 was significantly elevated(P0.05) in cows fed 0.5 g of BE kg–1. There were no treatment effects(P0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ ratio, or tumor necrosis factor-α(TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.     

Temporal dynamics of nutrient balance,plasma biochemical and immune traits,and liver function in transition dairy cows

The objective of this study was to analyze the dynamics of nutrient balance, physiological biomarkers and comprehensive indexes associated with metabolism and function of organs in transition cows. Fourteen transition cows were used for this research. Dietary intake was recorded daily, and samples of the diet, venous blood and milk were collected for measurements. The balance values of net energy for lactation(NE_L), metabolizable protein(MP), and metabolizable glucose(MG) were calculated, and regression analysis and calculation of comprehensive indexes were performed. Accordingly, the prepartum cows presented positive balances of NE_L, MP, and MG, while severe negative balances were found during the postpartum period. Dynamic changes of energy metabolism, nutrient mobilization, liver function, anti-oxidative status and immune response, as indicated by blood biomarkers and modified comprehensive indexes, were out of sync with the calculated balance values, but they were closely related to the day relative to calving. Compared with the 21 d prepartum, the plasma concentrations of non-esterified fatty acids(NEFA) and β-hydroxybutyric acid(BHBA) were significantly increased around and after calving(P0.05), and similar variation tendency was observed for most of other parameters. The occurrence of parturition and the initiation of lactation were more responsible for the negative balances of nutrients in transition dairy cows. Although negative balances of NE_L, MP and MG were not observed using the assessment model, the nutritional strategies should be applied before calving, because metabolic adaptations had been validated during the prepartum period. In addition, it was plausible to conclude that the decline of hepatic metabolism, defense function and insulin sensitivity are critical causes of metabolic dysfunction.     

Effect of dioscorea opposite waste on growth performance,blood parameters,rumen fermentation and rumen bacterial community in weaned lambs

This study investigated the effects of dioscorea opposite waste (DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs (male, (22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0 (control, CON), 10% (DOW1), 15% (DOW2) and 20% (DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher (P<0.05) dry matter intake (DMI) than the other groups. There was no significant difference (P>0.05) among DOW groups in average daily weight gain (ADG), and replacing concentrate with DOW linearly or quadratically increased (P<0.05) the ADG, while lambs fed the DOW2 diet showed greater (P<0.05) ADG than the CON group. The relative plasma concentration of growth hormone (GH), insulin like growth factor-1 (IGF-1) and insulin were affected by DOW, replacing concentrate with DOW linearly or quadratically (P<0.05) enhanced the plasma concentration of GH, IGF-1 and insulin, which was significantly higher (P<0.05) in the DOW2 group than in the CON, DOW1 and DOW3 groups. In addition, the DOW treatment showed a lower (P<0.05) concentration of blood urea nitrogen (BUN) than the CON group. Replacing concentrate with DOW quadratically decreased (P<0.05) the ruminal ammonia nitrogen (NH₃-N) and increased (P<0.05) the total of volatile fatty acids (TVFAs) at 0 and 4 h after feeding as well as linearly decreased (P<0.05) the NH₃-N at 8 h after feeding. Replacing concentrate with DOW linearly decreased (P<0.05) the propionate and increased the aceate before feeding, and linearly decreased (P<0.05) propionate and quadratically increased (P<0.05) the aceate at 4 and 8 h after feeding. Lambs fed the DOW2 diet increased the phylum Firmicutes and genera Succiniclasticum and Ruminococcus_1 groups, whereas decreased (P<0.05) the relative abundance of phylum Deferribacteres and genera intestinimonas and Ruminiclostridium. In summary, replacing the concentrate with 15% DOW was beneficial for improving the rumen fermentation and ADG by increasing the DMI and modulating the rumen microbial community.     

泌乳初期奶牛相关脂肪因子及生理生化指标与脂肪肝的相关性

为探究泌乳初期奶牛血清脂肪因子及生理生化指标与脂肪肝的相关性,选取四川某规模化奶牛场1~4胎围产期奶牛64头,分别于产后第7、14天早饲前尾静脉采血,检测产后第14天奶牛血清谷草转氨酶、血糖、游离脂肪酸水平,根据脂肪肝判定公式判定是否发生脂肪肝,检测并分析血清脂肪因子及生理生化指标与肝功能指标和能量代谢指标之间的相关性。结果显示,脂肪肝奶牛血清瘦素、脂联素水平显著低于健康奶牛(P<0.05),TNF-α水平显著高于健康奶牛(P<0.05),IL-6水平差异不显著(P>0.05)。瘦素水平与血糖、白蛋白呈显著正相关(P<0.05),与游离脂肪酸、β-羟基丁酸、谷草转氨酶、总胆红素、直接胆红素、总蛋白呈显著负相关(P<0.05),提示泌乳初期奶牛能量负平衡是脂肪肝发生的重要原因。脂联素水平与游离脂肪酸、β-羟基丁酸、谷草转氨酶呈显著负相关(P<0.05),与总蛋白、白蛋白呈显著正相关(P<0.05),提示泌乳初期脂肪肝奶牛存在着明显的肝功能损伤与脂质代谢紊乱。TNF-α水平与总胆红素、直接胆红素、谷丙转氨酶呈显著正相关(P<0.05),与血糖、白蛋白呈显著负相关(P<0.05);IL-6水平与谷丙转氨酶呈显著正相关(P<0.05),与总蛋白、白蛋白呈显著负相关(P<0.05),提示泌乳初期脂肪肝奶牛存在着明显的炎性反应。血清瘦素与脂联素水平呈显著正相关(P<0.05),与TNF-α呈显著负相关(P<0.05);TNF-α与脂联素呈显著负相关(P<0.05),与IL-6呈显著正相关(P<0.05),提示泌乳初期脂肪肝奶牛存在着糖脂代谢调控紊乱。综上所述,泌乳初期奶牛能量负平衡导致体脂动员,使得奶牛血清脂联素和瘦素水平下降,造成大量脂质合成于肝脏,肝脏功能受损,诱发炎性反应,TNF-α与IL-6水平随之上升,进而导致奶牛脂肪肝的发生,脂联素、瘦素和TNF-α可作为预测产后奶牛脂肪肝发生的指标。     

不同添加水平半胱胺对奶牛泌乳性能和血清生化指标的影响

为研究不同添加水平半胱胺盐酸盐(Cysteamine hydrochloride,CSH)对中国荷斯坦奶牛泌乳性能和血液生化指标的影响,选用40头产奶量、泌乳日龄和胎次相近的奶牛,随机分为5组,每组8头,每组日粮中CSH添加量分别为:0(对照组)、15、30、75和150g/头。预试期2周,正试期8周。结果表明:9~10周时150g处理组的干物质采食量显著低于15~75g处理组;5~8周15g处理组产奶量显著高于其他各处理组(P0.05),9~10周75和150g处理组产奶量显著低于0~30g处理组;5~10周15g处理组4%标准乳产量显著高于75~150g处理组(P0.05);5~8周150g处理组及9~10周75和150g处理组饲料转化率最低,且显著低于0~30g处理组(P0.05)。1~4周时75g处理组乳脂率及乳总固形物显著高于对照组(P0.05);3~4周时各试验组乳尿素氮浓度与对照组相比显著降低(P0.05)。1~2周75g处理组白蛋白浓度显著低于其他各处理组(P0.05),3~4周30g处理组白蛋白浓度最高,且显著高于其他各处理组(P0.05);9~10周时75~150g处理组尿素氮浓度较高,且75g处理组显著高于对照组(P0.05)。综上所述,在中国荷斯坦奶牛日粮中CSH的适宜添加量以每天每头15~30g为宜。     

奶牛临床和亚临床酮病的血浆代谢组学研究

【目的】基于代谢组学的气相色谱(GC)/质谱(MS)联用技术分析临床酮病、亚临床酮病和健康的奶牛血浆代谢谱,观察奶牛体内代谢产物的变化,寻找内源性代谢分子标记物,用于发现奶牛临床和亚临床酮病的早期诊断及病情进展的特征生物标志物,并阐明该病发病机制。【方法】收集临床酮病奶牛血样24例,亚临床酮病奶牛33例,健康对照组奶牛23例,静脉采集试验奶牛血液,分离血浆,检测其β-羟丁酸、血糖等生化指标。将血浆样品预处理后,运用GC/MS联用技术检测各组奶牛血浆代谢产物,利用质谱数据库对其进行鉴定。采用主成分分析（principal component analysis, PCA）和偏最小二乘判别分析法（partial least squares discriminant analysis, PLS-DA）等多元统计方法对临床酮病组、亚临床酮病组和健康对照组奶牛检测数据进行模式识别分析。通过PLS-DA方法建立疾病诊断模型后,筛选潜在的疾病生物标记物。【结果】 以80例奶牛血浆样品为分析对象,研究建立了内源性代谢物谱的GC/MS分析方法,并利用NIST（2008）商业质谱数据库对检测到的代谢物进行快速鉴定,共检测出267个变量。将代谢组数据导入SIMCA-P软件进行主成分分析和偏最小二乘法判别分析,代谢组数据可将患病组与健康组分别聚类区分,并且寻找到组间种类无差别代谢物为40种。结果显示与对照组相比,临床和亚临床酮病的差异代谢物均为32个,临床酮病与亚临床酮病组相比有13个差异代谢物。通过查找KEGG数据库,对代谢物进行分析,这些代谢物主要与氨基酸代谢、脂肪代谢和碳水化合物代谢等能量代谢途径相关。【结论】基于代谢组学的GC/MS技术对酮病奶牛血浆进行检测,并结合多元统计分析,共在临床、亚临床酮病和健康组之间发现40种代谢物（主要为脂肪酸,氨基酸和碳水化合物等物质）。证明奶牛血浆样品的GC/MS代谢谱可以有效地对临床酮病组、亚临床酮病组与健康对照组进行区分。该结果也进一步证明了利用代谢组学技术,在一定程度上可以揭示奶牛临床和亚临床酮病的发生和发展变化,而这些对组间分类有贡献的差异代谢物可能是奶牛酮病诊断的潜在代谢标记物和客观指标。通过研究可以发现奶牛临床和亚临床酮病的发生和发展过程中,其血浆内的部分代谢物的代谢模式和代谢途径发生了改变。此外,新的潜在的代谢物也为奶牛酮病的诊断和预防提供了一定的新思路。