中国荷斯坦牛白细胞粘附缺陷病遗传分析

荷斯坦牛白细胞粘附缺陷病（BLAD）是一种遗传性免疫缺陷病，患病牛出生后，生长发育差，绝大多数在1年内死亡，且不具繁殖和哺育能力。该病的遗传基础为CD18基因编码区383位的A／G点突变导致白细胞表面的β2整合素表达缺陷。目前欧美等奶牛业发达国家都已经建立了完善的BLAD分子检测方法和跟踪监控体系。中国长期从国外进口荷斯坦公牛精液、胚胎或活体，由此可能引进了BLAD基因。本研究采用PCR—RFLP方法对116头可疑中国荷斯坦牛进行了检测．确定了2头BLAD携带者公牛和8头携带者母牛．未发现隐性纯合个体．     

牛白细胞黏附缺陷病等位基因频率分析

为了解荷斯坦奶牛群中成母牛白细胞黏附缺陷病情况,抽取1 000头牛血样,采用RT-PCR方法对血样进行分析,并用TaqⅠ内切酶对RT-PCR产物进行消化,再用1.2%琼脂糖凝胶分析Taq Ⅰ限制性位点酶切片段.结果表明:1 000头荷斯坦奶牛中有19头BLAD基因携带者,1头BLAD基因纯合个体;BLAD基因携带者和纯合个体所占的比率分别为1.9%和0.1%;无BLAD和携带BLAD的基因频率分别为0.989 5和0.010 5.     

牛白细胞黏附缺陷病液相基因芯片检测方法的建立

从福建某奶牛场200头进口荷斯坦牛采血提取牛血液DNA,根据已知牛染色体上CD18编码基因序列383位基由A变为G而引起牛白细胞黏附缺陷症（BLAD）设计特异性野生型和突变型引物,建立液相基因芯片检测方法用于牛白细胞黏附缺陷症（BLAD）的检测,结果检出2头母牛为BLAD携带者,检出率为0．67％,没有发现患病牛。结果证明建立的液相基因芯片检测方法是一种敏感性和特异性很高的筛选奶牛BLAD有害基因的新方法     

北京地区荷斯坦牛BLAD遗传缺陷基因的分子筛查

牛白细胞黏附缺陷症(BLAD)是由常染色体上CD18基因单碱基突变(A→G)引起的隐性遗传疾病,隐性基因纯合时导致白细胞表面的β2整合素表达明显减少或缺乏而引起临床发病,患病牛的主要特征是机体免疫力降低、易患病,从而影响生产性能的表现,可严重影响奶牛场的经济效益。本研究利用PCR-SSCP方法对北京地区246头公牛样本和409头母牛样本进行了检测分析,研究结果表明,在所检测的样本中,荷斯坦种公牛(含后备公牛)和母牛BLAD携带率分别为0.81%和3.91%,BLAD基因频率分别为0.21%和1.95%,并通过系谱追踪发现,BLAD遗传缺陷可追溯到美国一头非常优秀的公牛Osborndale Ivanhoe(USA.1189870,BL),其后代在我国有一定的影响。通过剔除BLAD携带者公牛可以有效控制该遗传缺陷的传播,但是,我国部分BLAD携带者公牛冻精依然在商业化使用,所以,有效监控BLAD携带者在奶牛群中的状况对BLAD剔除计划是有益的。     

Bovine mycoplasmas: cultural and biochemical studies. I

A survey is given of presently known mycoplasmas of bovine source. Media and methods of cultivation are described. Cholesterol dependence, being the basis of division of Mycoplasmatales into Mycoplasmataceae and Acholeplasmataceae, was examined directly and also indirectly employing sensitivity tests to digitonin and sodium polyanethole sulphonate (SPS). All by now recognized species were found to be correctly classified in Mycoplasma and Acholeplasma, respectively. Of the unnamed “serogroups” 2 should be classified in the latter genus, while 6 serogroups were members of the genus Mycoplasma. Correlation was found between the digitonin test and the direct determination of cholesterol requirement, whereas this was not the case with the SPS test.     

Correlation of Serum Cardiac Troponin I and Myocardial Damage in Cattle with Monensin Toxicosis

Background: Cardiac troponin I (cTnI) is used as a biomarker of myocardial injury in people and small animals. Little is known about the diagnostic use of cTnI in cattle.
Hypothesis: Serum cTnI correlates to myocardial function and histopathologic lesions in cattle with monensin-induced myocardial injury.
Animals: Ten healthy cows.
Methods: Experimental study. Animals received 1 dose of monensin PO; 30 mg/kg (n = 1) or 40 mg/kg (n = 1) (Group A) or 50 mg/kg monensin (n = 8) (Group B) of body weight. Repeated measurements were performed of serum cTnI, biochemistry, and ECG and echocardiography until study termination at 80 (Group A) and 144 hours (Group B) after dosing. Semiquantitative histopathologic examinations of the heart were performed in each cow. A scoring system with regard to the magnitude of myocardial injury was established and a total heart score was compared with maximum cTnI concentration measured after monensin administration. Five hearts from healthy cows served as controls.
Results: Increased cTnI (>0.07 ng/mL) was found in 9/10 cows. cTnI was significantly associated with left ventricular shortening fraction ( r ²= 0.51; P = .02) and myocardial histopathologic lesion score ( r ²= 0.49; P = .021). All cows (n = 7) with evidence of myocardial necrosis had a cTnI concentration ≥ 1.04 ng/mL.
Conclusion and Clinical Importance: cTnI is related to myocardial necrosis and severity of myocardial damage in cattle with monensin toxicosis. cTnI could become a useful diagnostic tool in the noninvasive assessment of myocardial injury in cattle with naturally occurring cardiac disease.     

Obstruction of the Ascending Colon in Cattle: I. Clinical Presentation and Surgical Management

Obstruction of the spiral loop of the ascending colon (spiral colon) due to adhesions causing extraluminal constriction was diagnosed in 8 cows during a 2-year period. The adhesions resulted from intraperitoneal injections in 7 cows and from previous intra-abdominal surgery in the 8th. Surgical correction was performed in 4 of the cows by uniting the bowel proximal and distal to the obstruction, thus creating an intestinal bypass. Approximately half of the large intestine was bypassed in this manner in 3 cows; all but a portion of the descending colon and rectum was bypassed in the 4th. Each of the cows survived surgery, although 1 died 30 days later, possibly as a result of a second obstruction caused by further adhesions. Appetite, general physical condition, and milk production returned after celiotomy and intestinal bypass. Feces were loose after operation but gradually firmed to near-normal consistency in 3 of the cows.     

Physiological parameter values for physiologically based pharmacokinetic models in food-producing animals. Part I: Cattle and swine

Physiologically based pharmacokinetic (PBPK) models for chemicals in food animals are a useful tool in estimating chemical tissue residues and withdrawal intervals. Physiological parameters such as organ weights and blood flows are an important component of a PBPK model. The objective of this study was to compile PBPK-related physiological parameter data in food animals, including cattle and swine. Comprehensive literature searches were performed in PubMed, Google Scholar, ScienceDirect, and ProQuest. Relevant literature was reviewed and tables of relevant parameters such as relative organ weights (% of body weight) and relative blood flows (% of cardiac output) were compiled for different production classes of cattle and swine. The mean and standard deviation of each parameter were calculated to characterize their variability and uncertainty and to allow investigators to conduct population PBPK analysis via Monte Carlo simulations. Regression equations using weight or age were created for parameters having sufficient data. These compiled data provide a comprehensive physiological parameter database for developing PBPK models of chemicals in cattle and swine to support animal-derived food safety assessment. This work also provides a basis to compile data in other food animal species, including goats, sheep, chickens, and turkeys.     

Biology of the prolactin family in bovine placenta. I. Bovine placental lactogen: Expression, structure and proposed roles

Bovine placenta produces an array of proteins that are structurally and functionally similar to pituitary prolactin. Bovine placental lactogen (bPL) is a glycoprotein hormone that has lactogenic and somatogenic properties. Purified bPL contains several kinds of isoforms that are created by alternative splicing and/or multiple glycosylation patterns. bPL can activate the prolactin (PRL) receptor‐mediated signaling pathway as well as PRL does. The bPL mRNA is transcribed in trophoblast binucleate cells, and synthesized bPL protein is stored in membrane‐bound secretory granules. The message encoding bPL is first detectable in trophoblast binucleate cells at approximately day 20 of gestation at, or shortly after, the appearance of binucleate cells in the trophoblast. Most binucleate cells are detected as expressed bPL in the placenta. Bovine PL may be the determinant in trophoblast differentiation. Although the biological activities of bPL have long been studied, the precise role of bPL is still largely unclear. This article reviews and discusses the biological roles of bPL, focusing on luteal function, fetal growth and pregnancy‐associated maternal adaptation, mammogenesis and lactogenesis, and placental angiogenesis. The precise biological function of bPL needs to be further evaluated.     

Associations of Neospora caninum seropositivity with gestation number and pregnancy outcome in Danish dairy herds.

The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test. Seroprevalence in 15 herds with previous abortions assigned to neosporosis ranged from 1% to 58%, with a mean frequency of 22%. In eight out of 16 herds without a history of N. caninum related abortions, no seroreactors were found. In the remaining eight herds, the seroprevalence ranged from 6% to 59%. The prevalence and distribution of seropositivity, gestation number prior to sampling, and breed were related to abortions and perinatal deaths using a random-effects logistic-regression model. Abortion risk was significantly increased in seropositive animals (OR=3) and in 2nd-gestation cows (OR=3). Perinatal death was significantly influenced by gestation number and breed, but not by serostatus. Reproductive performance and culling risk of cows were not affected by serostatus. Seropositivity increased with “age” (i.e. gestation number) (P=0.02). In open cows, seropositivity tended to decrease with distance from calving (P=0.05). The proportion of seropositive pregnant cows increased with trimester (P=0.02).     

Pathological Lesions in Swine at Slaughter: I. Baconers

An extended disease recording programme in pigs has been carried out by the meat inspection service at Sentralslakteriet, Forus, Stavanger. A data system including 57 disease codes has been applied. In the period 1975–1977 an average of 85,000 baconers were slaughtered yearly. About 39 % of these were given disease remarks; 42–47 % of the lesions were directly related to the parasites Sarcoptes scabiei (rind lesions) and Ascaris suum (white spots in the livers). The thoracic cavity was the most commonly affected part of the body with 30–35 % of all recorded lesions.Sixteen disease codes occurred at frequencies above 0.3 %, and they encompassed approx. 97 % of all recorded lesions. Scabies occurred at an average of 12 % of the fatteners. Parasitic hepatitis of severe and moderate degrees were seen in about 11 %, pleurisy in 7 %, pneumonia — severe and moderate — in 5.4 %, pericarditis in 4.3 %, pyaemia and abscess/-es in 2.5 %, tail lesions in 2.3 %, perihepatitis and other non-parasitic liver lesions in 2.2 %, polyarthritis and arthritis in 1.7 %, tuberculous lesions in the cervical lymph nodes in 0.9 %, peritonitis in 0.9 % and atrophic rhinitis — external lesions — in 0.8 % of the carcasses. The majority of the other 41 disease codes occurred at frequencies below 0.1 %.A seasonal variation was pronounced in scabies, numerous white spots in the liver, and tuberculous lesions in the cervical lymph nodes. It could be noted in pleurisy, pericarditis, perihepatitis and other non-parasitic liver lesions, arthritis and atrophic rhinitis, but not in pneumonias, moderate number of white spots in the liver, tail lesions, pyaemia, abscess/-es, peritonitis and polyarthritis.     

An Outbreak of Gangrenous Syndrome among Buffaloes and Cattle in West Bengal: Clinicopathological Studies

Gangrenous syndrome/Degnala disease was recorded in a large number of buffaloes and cattle in Murshidabad district of West Bengal, India. Fusarium spp. had been isolated from the mouldy paddy straw which were fed to the animals. There was a reduction in the incidence of the disease following withdrawal of the mouldy paddy straw. Histopathological examination showed necrosis and loss of architectural details in the skin.