维生素E与母牛繁殖

维生素E是一种有效的抗氧化剂，具有广乏的生理功能，对提高机体免疫力，提高母牛繁殖力和预防产科疾病有重要的意义。本文从它的生理功能、来源及与母牛繁殖关系的最新研究成果进行了综述。     

奶牛布鲁氏菌病的病原分离鉴定及血清学研究

通过细菌分离、动物试验、细菌学与血清抗体之间相互关系、温度与感染动物之间相互关系等分离一例奶牛布鲁氏菌。发现细菌学与血清抗体呈平行关系，试管凝集反应与补体结合反应存在一定差异，感染动物14天出现波浪热，持续到剖杀前(31天)。     

奶牛乳腺炎防治的免疫学和药理学机制

奶牛乳腺炎是一种复杂的多因素疾病，给世界各国奶牛业造成了巨大的经济损失，而至今未能提出一个彻底解决的办法。本文综述了奶牛乳腺炎的致病因素、乳腺的免疫机制和乳腺炎治疗的药理学机制方面的研究进展，重点剖析了乳腺特殊的免疫体系和乳腺炎治疗的药理学特点，分析阐明了奶牛乳腺炎免疫和治疗失败的原因。     

奶牛冷冻胚胎规模化移植效果研究

为了提高奶牛良种化程度,对奶牛冷冻胚胎的规模化移植效果进行了研究。结果表明:PG二次肌注法的发情率显著高于(P<0.05)PG一次肌注法,两种方法的发情同期率均超过85%,受体牛发情时间多集中在肌注PG后48～72h;胚胎解冻后的复苏率达到82.58%,且早期囊胚与囊胚的复苏率要高于桑椹胚(P>0.05);共移植受体牛218头,受胎97头,受胎率为44.5%,且春、秋季的移植效果差异不显著(P>0.05)。为奶牛冻胚的规模化移植研究提供了参考依据。     

奶牛乳房炎多联苗(B)的临床免疫试验

用奶牛乳房炎多联苗 (B)免疫家兔 ,14 d血清中金黄色葡萄球菌抗体效价可达 1∶ 8,2 8d抗体水平明显升高 ,可达 1∶ 32 ,注苗后 35 d攻毒 ,攻毒后 2 d保护率为 93.3% (14 /15 ) ,自然保护率为 2 0 % (1/5 ) ,10 d保护率为 6 6 .6 % (10 /15 ) ,自然保护率为 2 0 % (1/5 ) ;用多联苗 (B)臀部肌肉注射免疫泌乳牛 ,试验期间 4个月内 ,3ml剂量组临床型乳房炎月平均发病率为 11.0 9% ,其对照组为 2 0 .19% ,发病率降低 4 5 .2 9% ,差异极显著 (P<0 .0 1) ;5 m l剂量组月平均发病率为 13.0 1% ,其对照组为 31.36 % ,发病率降低 5 8.5 1% ,差异极显著 (P<0 .0 1) ;3ml剂量组与 5 m l剂量组之间发病率无明显差异 (P>0 .0 5 ) ;注苗后泌乳牛血清抗体水平可持续 4个月 ,且 30 d时效价水平最高。     

Inflammation-related changes in cyclic AMP and cyclic GMP in bovine mastitis

Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) cocentrations in milk and plasma samples from healthy and mastitic cows were determined by radioi-immunoassay and compared with prostaglandins (PGE2, PGF2 and thromboxane B2 [TXB2]), phospholipids and other relevant parameters in milk and blood. The concentrations of cAMP were about five times higher in plasma (p<0.01) than in milk, whereas the cGMP concentration in milk was three times higher (p<0.01) than that in plasma in both healthy and diseased animals. In mastitic milk, the cAMP and cGMP concentrations were 19% and 65% and in blood plasma 13% and 84% higher respectively than in healthy animals. In milk, cyclic nucleotide concentrations correlated with the markedly elevated cell count and also with the prostaglandin concentration and pH. In blood, cAMP correlated positively with phospholipids and cGMP with reduced glutathione (GSH). These changes are considered to be important in the disease process and, in particular, the increase in cGMP deserves further study.     

亚热带牧用草地中威提特东非狼尾草的种子繁殖研究

在3月和4月对全日制放牧的东非狼尾草草地上的风干牛粪取样,进行发芽试验,分别测定其中的东非狼尾草发芽种子数量。结果,3月取样平均432.5 g的牛粪中东非狼尾草平均发芽种子数量为118.25粒,4月取样平均437.8 g的牛粪中东非狼尾草平均发芽种子数量为52.8粒,二者平均牛粪重为435.15 g,平均发芽种子为85.5粒,说明牛粪中东非狼尾草种子数量较多,是其繁殖扩展较快的主要原因;3月取样的种子数量为4月取样数量的1.38倍,说明人工利用牛粪进行东非狼尾草繁殖时,需在有降雨来临前准备,即1～3月进行牛粪的准备工作。     

荷斯坦奶牛隐性乳房炎与乳用特征的相关性分析

随机抽取荷斯坦奶牛 472头 (1～ 11胎 )进行奶牛隐性乳房炎的检测 ,乳用特征性状 (楞角性、尻宽、尻角度、后肢侧视、蹄角度 )的线性评定 ,以及隐性乳房炎与乳用特征的相关性分析。结果表明 :奶牛隐性乳房炎的乳区阳性率与楞角性、尻宽、尻角度、后肢侧视、蹄角度的相关系数分别为 0 1171、0 10 3 0、0 0 681、0 0 180、-0 12 65 ,其中与楞角性、尻宽分别达到显著水平 (P <0 0 5 )的正相关 ,与蹄角度达极显著 (P <0 0 1)的负相关。奶牛阳性率与楞角性、尻宽、尻角度、后肢侧视、蹄角度的相关系数分别为 0 0 967、0 0 5 61、0 0 2 82、0 0 12 7和 -0 0 670 ,其中除与楞角性为显著水平 (P <0 0 5 )的正相关 (0 0 967)外 ,其余均不显著 (P >0 0 5 )。     

Noninferiority trial investigating the efficacy of a nonantibiotic intramammary therapy in the treatment of mild‐to‐moderate clinical mastitis in dairy cows with longer lasting udder diseases

A nonblinded, positively controlled, noninferiority trial was conducted to evaluate the efficacy of an alternative, nonantibiotic therapy with Masti Veyxym^® to reduce ineffective antibiotic usage in the treatment of nonsevere clinical mastitis (CM) in cows with longer lasting udder diseases. The solely intramammary treatment with Masti Veyxym^® (three applications, 12 hr apart) and the combined treatment with Masti Veyxym^® and antibiotics as usual on the farm according to label of the respective product were compared with the reference treatment of solely antibiotic therapy. The matched field study was conducted on eight free‐stall dairy farms located in Eastern Germany. Cases of mild‐to‐moderate CM in cows with longer lasting high somatic cell counts in preceding dairy herd improvement test days and with previous CM cases in current lactation were randomly allocated to one of the three treatment groups. A foremilk sample of the affected quarter was taken before treatment and again approximately 14 days and 21 days after the end of therapy for cyto‐bacteriological examination. Primary outcomes were clinical cure (CC) and no CM recurrence within 60 days after the end of treatment (no R60). Bacteriological cure (BC) and quarter somatic cell count (QSCC) cure were chosen as secondary outcomes although low probabilities of BC and QSCC cure for selected cows were expected. The study resulted in the following findings: the pathogens mostly cultured from pretreatment samples were Streptococcus uberis, followed by Staphylococcus aureus and coagulase‐negative staphylococci. There were no significant differences between the two test treatments in comparison with the reference treatment regarding all outcome variables. The sole therapy with Masti Veyxym^® resulted in a numerically lower likelihood of BC without significant differences to the reference treatment. The combined therapy group showed a numerically higher nonrecurrence rate than the two other treatment groups and noninferiority compared to the reference treatment was proven. Having regard to the selection criteria of cows in this study, the findings indicated that sole treatment with Masti Veyxym^® in nonsevere CM cases may constitute an alternative therapy to reduce antibiotics. However, noninferiority evaluations were mostly inconclusive. Further investigations with a larger sample size are required to confirm the results and to make a clear statement on noninferiority.