奶牛血液抗氧化酶活性的季节变化

为了研究奶牛耐热性与体内抗氧化酶活性的相关性,本试验选择胎次相近的35头荷斯坦奶牛,按夏季产奶量下降率分为耐热组(下降率10%以下)和热应激组(下降率40%以上),分别测定春季、夏季试验牛血浆中超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力,以及丙二醛(malondialdehyde,MDA)含量。结果表明:(1)奶牛血液抗氧化指标受季节性影响较大,夏季血浆中SOD活力、GSH-Px活力极显著低于春季(P<0.01),夏季MDA含量极显著高于春季(P<0.01);(2)血液中抗氧化指标在同一季节、不同组别之间差异较大,春季耐热组SOD活力极显著高于热应激组(P<0.01),耐热组MDA含量显著低于热应激组(P<0.05),夏季耐热组SOD活力、GSH-Px活力显著高于热应激组(P<0.05),耐热组MDA含量显著低于热应激组(P<0.05);(3)夏季奶牛血液中GSH-Px活力及MDA含量分别与夏季奶牛产奶量下降率极显著强负相关(r=?0.710,P<0.01)和极显著强正相关(r=0.733,P<0.01),夏季血液中SOD活力与夏季奶牛产奶量下降率之间没有显著的相关性,夏季GSH-Px活力下降率与产奶量下降率间呈显著正相关(r=0.493,P<0.05),但夏季血液中SOD活力下降率和MDA上升率与夏季奶产量下降率之间无显著的相关性。以上结果提示:(1)奶牛血液抗氧化酶受季节影响较大;(2)奶牛的耐热性可能与血液的抗氧化性相关。     

中草药对热应激奶牛生产性能和血液指标的影响

选择经产、胎次相同和产奶量相近的荷斯坦奶牛30头，随机分为对照组、试验1组和试验2组．每组10头。对照组饲喂基础日粮，试验组精料中每头每天添加300g复方中草药。测定产奶量、直肠温度，采集血样以放射免疫法测定外周血清中COR、ACTH、IL-2、IL-6的水平，用全自动血液分析仪测定全血中WBC等20项指标。结果显示：（1）在9月2日～9月15日期间，试验组产奶量比对照组显著增加；（2）血清COR和ACTH水平在热应激条件下显著上升，而白细胞介素水平在热应激条件下显著下降，中草药处理组的激素水平均得到显著缓解（P〈0．05）：（3）在血液指标分析中，WBC、LY、Hb、RBC、HCT在热应激条件下，随着温度的升高而明显下降，表明中草药能有效缓解奶牛热应激．     

竹叶提取物对热应激奶牛泌乳性能及血清生化、抗氧化和免疫指标的影响

本试验旨在研究竹叶提取物对热应激奶牛泌乳性能及血清生化、抗氧化和免疫指标的影响。试验于2019年7—8月进行,试验期间日平均温湿度指数为75.87,奶牛处于自然热应激状态。选取24头体重[(559.2±37.4)kg]、泌乳天数[(185.7±16.9)d]、胎次[(3.3±0.3)胎]和产奶量[(37.6±0.8)kg/d]相近的荷斯坦奶牛,随机分为2组,每组12头。对照组饲喂全混合日粮(TMR),试验组在TMR基础上添加1.3 g/kg DM的竹叶提取物。预试期14 d,正试期21 d。分别于正试期第1、11、21天测量奶牛呼吸频率、直肠温度并采集血样和奶样,测定泌乳性能及血清生化、抗氧化和免疫指标。结果表明:1)试验组热应激奶牛的呼吸频率极显著低于对照组(P<0.01),直肠温度与对照组相比有降低的趋势(P=0.09)。2)试验组热应激奶牛的产奶量和乳脂率极显著高于对照组(P<0.01),乳中体细胞数与对照组相比有降低的趋势(P=0.09),但干物质采食量、乳蛋白率和乳糖率与对照组无显著差异(P>0.05)。3)试验组热应激奶牛的血清肾上腺素含量极显著高于对照组(P<0.01),血清前列腺素-2含量显著高于对照组(P<0.05),血清游离脂肪酸含量与对照组相比有升高的趋势(P=0.06),但血清糖皮质激素、三碘甲状腺原氨酸、甲状腺素、葡萄糖含量及乳酸脱氢酶活性与对照组无显著差异(P>0.05)。4)试验组热应激奶牛的血清超氧化物歧化酶和谷胱甘肽过氧化氢酶活性极显著高于对照组(P<0.01),血清丙二醛含量极显著低于对照组(P<0.01)。5)试验组热应激奶牛的血清肿瘤坏死因子-α和白细胞介素-2含量极显著高于对照组(P<0.01),血清白细胞介素-1和白细胞介素-1β含量极显著低于对照组(P<0.01),血清免疫球蛋白A含量显著高于对照组(P<0.05),血清免疫球蛋白G含量与对照组相比有升高的趋势(P=0.08),但血清干扰素-γ、白细胞介素-6和免疫球蛋白M含量与对照组无显著差异(P>0.05)。综上所述,饲粮中添加1.3 g/kg DM竹叶提取物降低了热应激奶牛的呼吸频率和直肠温度,提高了泌乳性能,缓解了机体的代谢紊乱,增强了机体的抗氧化能力,改善了机体的免疫功能。     

一种抗热应激添加剂对奶牛热应激防控效果的研究

为了研究一种抗热应激添加剂对奶牛泌乳期(173±13)d和热应激期生产性能、抗氧化能力和能量代谢等相关指标的影响,试验选择26头热应激条件下的泌乳期荷斯坦奶牛,采用完全随机试验设计将其分为2组,每组13头,其中对照组奶牛饲喂基础日粮,饲喂组奶牛饲喂基础日粮与300 g抗热应激添加剂,试验期为42 d。在试验开始前检测26头奶牛的产奶量,在正式试验的第7,14,21,28,35,42天记录产奶量,利用乳成分分析仪测定乳脂率、乳蛋白率、脂蛋比、尿素氮含量。在试验期第0,5,10,15,20,25,30天尾静脉采血,10 mL/头,自然凝固后取上清液检测热休克蛋白70(HSP70)、抗氧化指标谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)、丙二醛(MDA)、β-羟丁酸(BHBA)、游离脂肪酸(NEFA)、球蛋白、白球比、总蛋白、免疫球蛋白G(IgG)、免疫球蛋白M(IgM)等血液生化指标。结果表明:抗热应激添加剂可以缓解热应激,且饲喂组HSP70水平在第10,20天极显著低于对照组(P0.01),在第5,30天显著低于对照组(P0.05)。试验使用的抗热应激添加剂可以提升热应激期间奶牛奶产量,达到2.28 kg/d。抗热应激添加剂可以提高乳品品质,饲喂组乳脂率显著高于对照组(P0.05)。抗热应激添加剂可以提高泌乳奶牛的抗氧化能力,饲喂组SOD活性在第10,15,20,25,30天极显著高于对照组(P0.01);MDA含量在第15, 20,30天极显著低于对照组(P0.01),而在第10天显著低于对照组(P0.05)。抗热应激添加剂可以减少奶牛能量代谢障碍性疾病发生,提高奶牛的健康水平,饲喂组BHBA水平在第5,10,20天极显著低于对照组(P0.01);NEFA水平在第20天极显著低于对照组(P0.01),而在第10天显著低于对照组(P0.05)。抗热应激添加剂对乳蛋白率、脂蛋比、尿素氮、GSH-Px、球蛋白、白球比、总蛋白、IgG、 IgM的影响均差异不显著(P0.05)。说明该抗热应激添加剂具有提高奶牛生产性能、缓解奶牛热应激症状、改善机体代谢等作用。     

抗热应激剂对夏季奶牛生理及乳成分的影响

研究不同配比的中草药抗热应激添加剂对缓解泌乳期奶牛热应激的效果。试验选用18头体质量、胎次和产奶量均相近的中国荷斯坦奶牛,采用完全随机设计,分为3个处理组,即使用不同中草药配伍的配方1组、配方2组和空白对照组。结果表明:试验第3周,配方1组和2组与对照组相比,产奶量分别提高15.67%和15%,差异显著;试验第1周末,配方1组和2组奶牛呼吸数较对照组显著降低;试验第3周末,配方1组和2组奶牛脉搏数较对照组显著降低。2个配方组牛乳成分与对照组相比无显著差异。说明奶牛日粮中添加抗热应激中草药添加剂可以有效缓解热应激对奶牛的不良影响,同时不影响奶牛的产奶性能。     

"抗热应激中草药添加剂"对奶牛产奶量和乳汁成分的影响

夏季热应激是影响奶牛产奶量的一个重要因素。采用中兽医学理论对夏季热应激奶牛进行辨证施治 ,组方“中草药饲料添加剂”作为抗热应激缓冲剂。选择 1 6头年龄、胎次、生产性能相似的奶牛分成 2组 (每组各 8头 )进行添加剂饲喂试验。结果表明 ,添加中草药复合剂的试验组产奶量比空白对照组明显提高 (P <0 .0 5) ,试验组的乳汁监测也表明 ,中草药添加剂在提高奶牛产奶量的同时 ,不但不影响牛奶品质 ,还能提高牛奶营养成分。血液生化指标证明中草药添加剂还能提高奶牛的免疫力     

中草药添加剂对热应激奶牛产奶性能和血液生化指标的影响

本文旨在研究复方中草药添加剂对热应激奶牛干物质采食量、泌乳性能和血液生化指标的影响。试验挑选60头体况、产奶量、泌乳日龄和胎次相近的荷斯坦奶牛,采用完全随机试验设计,随机分为4组,每组15头奶牛,每组分别在基础饲粮中添加0、100、200和300 g/头·d的复方中草药添加剂,预饲期1周,正试期8周。结果表明,200和300 g/头·d添加组奶牛的干物质采食量和产奶量显著高于0和100 g/头·d添加组奶牛(P0.05)。复方中草药添加剂对热应激奶牛的乳成分无显著影响(P0.05)。复方中草药添加剂显著提高了热应激奶牛血液甲状腺激素和皮质醇浓度(P0.05),其中以200 g/头·d添加组浓度最高。复方中草药添加剂显著提高了热应激奶牛血液超氧化物歧化酶和谷胱甘肽过氧化物酶活性,降低了血液丙二醛含量。综上所述,本试验条件下使用的复方中草药添加剂以200 g/头·d的添加剂量具有最佳效果,可以显著改善热应激奶牛的干物质采食量和泌乳性能。     

奶牛血液抗氧化酶活性的季节变化

为了研究奶牛耐热性与体内抗氧化酶活性的相关性,本试验选择胎次相近的35头荷斯坦奶牛,按夏季产奶量下降率分为耐热组（下降率10%以下）和热应激组（下降率40%以上）,分别测定春季、夏季试验牛血浆中超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活力,以及丙二醛（malondialdehyde,MDA）含量.结果表明：（1）奶牛血液抗氧化指标受季节性影响较大,夏季血浆中SOD活力、GSH-Px活力极显著低于春季（P＜0.01）,夏季MDA含量极显著高于春季（P＜0.01）;（2）血液中抗氧化指标在同一季节、不同组别之间差异较大,春季耐热组SOD活力极显著高于热应激组（P＜0.01）,耐热组MDA含量显著低于热应激组（P＜0.05）,夏季耐热组SOD活力、GSH-Px活力显著高于热应激组（P＜0.05）,耐热组MDA含量显著低于热应激组（P＜0.05）;（3）夏季奶牛血液中GSH-Px活力及MDA含量分别与夏季奶牛产奶量下降率极显著强负相关（r=-0.710,P＜0.01）和极显著强正相关（r=0.733,P＜0.01）,夏季血液中SOD活力与夏季奶牛产奶量下降率之间没有显著的相关性,夏季GSH-Px活力下降率与产奶量下降率间呈显著正相关（r=0.493,P＜0.05）,但夏季血液中SOD活力下降率和MDA上升率与夏季奶产量下降率之间无显著的相关性.以上结果提示：（1）奶牛血液抗氧化酶受季节影响较大;（2）奶牛的耐热性可能与血液的抗氧化性相关.     

中草药制剂对热应激奶牛泌乳性能、抗氧化能力及免疫功能的影响

为探讨复合中草药制剂对热应激奶牛泌乳性能、抗氧化能力及免疫功能的影响,选择产奶中后期的健康中国荷斯坦奶牛20头,按泌乳时间和产奶量相近的原则均分为A、B、C和D 4组。A组为对照组,饲喂基础日粮;B、C和D组分别在每头牛的基础日粮中添加50,100和150 g/d水平的复合中草药制剂。每天测定产奶量,在试验的第1(添加复合中草药制剂之前)、20和40天逐头采集血样,测定不同剂量复合中草药制剂对热应激奶牛血淋巴细胞凋亡率、血液抗氧化酶GSH-Px、CAT基因及血淋巴细胞凋亡相关基因Bcl-2、p53表达水平的影响。结果表明,B、C和D组的日产奶量较对照组分别提高了20.26%(P<0.05),24.20%(P<0.05)和16.98%(P>0.05);乳中体细胞数较对照组分别降低了21.68%(P<0.05),29.88%(P<0.05)和24.22%(P<0.05);奶牛血液抗氧化酶GSH-Px、CAT基因的表达水平分别比对照组提高了5.00%(P>0.05),13.00%(P<0.05),6.00%(P>0.05)和5.00%(P>0.05),16.00%(P<0.05),3.00%(P>0.05);奶牛血淋巴细胞平均凋亡率分别比A组降低了18.20%(P>0.05),17.86%(P>0.05)和12.51%(P>0.05);奶牛血淋巴细胞Bcl-2在20,40 d时均极显著高于A组,全期的平均水平分别比对照组高出105.00%(P>0.05),113.00%(P>0.05)和57.00%(P>0.05);p53基因的表达水平在20,40 d时均极显著低于A组,全期的平均水平分别比对照组降低了24.00%(P>0.05),28.00%(P>0.05)和20.00%(P>0.05)。试验组中,C组奶牛的日产奶量、体细胞数、血液抗氧化酶活性、淋巴细胞凋亡相关基因表达等指标要优于B、D组;而血液淋巴细胞凋亡率指标为B组最好。说明复合中草药制剂能有效改善热应激奶牛的泌乳性能、抗氧化能力及免疫功能,且在本试验条件下,每头牛日粮中添加100 g/d水平的效果要优于50及150 g/d水平。     

缓解奶牛热应激的营养调控措施

[目的]为探讨中草药发酵制剂缓解奶牛热应激的调控作用和缓解奶牛热应激的营养调控措施。[方法]选用胎次相近、健康无病,体况均匀的40 头,随机分成4 组,分别设置为对照组、试验Ⅰ组、试验Ⅱ组、试验Ⅲ组,每组5 个重复,每个重复2 头。对照组奶牛饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组分别在饲喂基础日粮的基础上添加1%、2%和3%的中草药发酵制剂。[结果]通过检测生理指标、泌乳性能和血清生化指标结果表明,添加中草药发酵制剂后热应激奶牛的直肠温度和呼吸频次显著降低,平均日增重、平均日采食量显著提高,料重比显著降低（P<0.05）;奶牛的产奶量、乳脂率和乳蛋白率显著升高,体细胞数显著降低（P<0.05）;奶牛的白蛋白、总蛋白、尿素氮、血糖、谷丙转氨酶和谷草转氨酶含量均显著升高（P<0.05）。[结论]中草药发酵制剂可以有效缓解奶牛热应激,恢复正常的生理指标和血清生化指标水平,提高奶牛泌乳性能。在本试验条件下,日粮中中草药发酵制剂的适宜添加量为3%。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.