犬肘关节发育不良

肘关节发育不良(elbow dysplasia，ED)是继犬髋关节发育不良(canine hip dysplasia)之后逐渐被人们认识的一种严重的遗传性疾病。此病发生于幼犬阶段，终生影响犬的运动，在某些品种或犬群中发病率很高，特别是工作犬品种，如罗威纳犬(41．8％)、德国牧羊犬(20．2％)、英国史宾格犬(14．1％)和拉布拉多犬(12．5％)等。因此，近年来此病愈来愈受到世界各地兽医工作者与养犬爱好者的重视，有关这方面的研究报道很多。     

通过CHD基因快速鉴定鸽子性别方法的研究

本试验采用PCR方法,依据性别基因连锁理论,通过羽毛和血液,不提取鸽子基因组DNA,直接利用特异性引物对其CHD基因的特异性片段进行扩增,琼脂糖凝胶电泳检测,结果显示雄鸽仅有1条带,在700bp左右,雌鸽有2条带,分别在400与700bp左右;利用该检测方法对100羽性别未知的雏鸽进行了性别鉴定,结果为雌鸽48羽、雄鸽52羽,并通过剖解雄鸽的生殖器官进行验证,准确率达到100%。用建立的方法测定了2928羽雏鸽用于蛋鸽留种试验,结果表明,雌鸽为1411羽、雄鸽为1517羽。     

Study on Quick Sex Identification Method in Pigeons by CHD Gene

In this experiment, the primer pairs were designed, and polymerase chain reaction (PCR) technique to amplify the segments of the partial sex linked gene chromo-helicase-DNA-binding (CHD) to identificate pigeon's sex using feather pulps and blood.We found that two bands were demonstrated in all female egg-laying pigeons, and the sizes of them were 400 and 700 bp, respectively;In all male egg-laying pigeons, only one band appeared with length of 700 bp.100 unknown sex samples were successfully identified (52 males and 48 females).Based on the checking results between molecular electrophoresis of pigeons and the truly sex of maturity pigeons, we detected CHD gene in 2 928 early age pigeons using PCR amplification and electrophoresis in agarose gel.The PCR amplification results showed 1 517 males and 1 411 females.     

Immunization-induced decrease of the CD4+:CD8+ ratio in cats experimentally infected with feline immunodeficiency virus.

In a previous experiment a group of 15 specified pathogen free (SPF) cats were experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV). A group of 15 SPF cats served as FIV negative controls. Nine cats of each group were vaccinated with a recombinant feline leukemia virus (FeLV) vaccine, six cats in each group with a placebo vaccine. All vaccinated cats developed high antibody titers to FeLV and were protected against subsequent FeLV challenge infection. In both control groups five of six cats became persistently infected with FeLV. Unexpectedly, the primary immune response to the vaccine antigen was significantly higher in the FIV positive group than in the FIV negative. The secondary response was stronger in the FIV negative cats. The goal of the present investigation was to further study the immune response in these 30 cats. They were immunized twice with the synthetic peptide L-tyrosine-L-glutamic acid-poly(DL-alanine)-poly(L-lysine) (TGAL) 21 days apart. Blood samples were collected on four occasions during the immunization process. They were tested for antibodies to TGAL, complete blood cell counts and CD4+, CD8+ and pan-T-lymphocyte counts. The following observations were made: (1) in contrast to the FeLV vaccine experiment, the primary immune response to TGAL was not significantly stronger in the FIV positive cats when tested by enzyme-linked immunosorbent assay (2). The absolute size of the CD4+ lymphocyte population was distinctly smaller in the FIV positive than in the FIV negative cats. The lowest CD4+ values were found in the dually FIV/FeLV infected cats. (3) A population of CD8+ lymphocytes was identified that was characterized by a distinctly weaker fluorescence. The size of this population increased in FIV positive and decreased in FIV negative cats during the TGAL immunization experiment. (4) The CD4+:CD8+ ratio increased in FIV negative cats during TGAL immunization from 1.9 to 2.3. In contrast, in FIV positive animals the CD4+:CD8+ ratio decreased significantly from 1.9 to 1.3 during the same period. From these and earlier data it was concluded that in short-term FIV infection the immune response to T-cell dependent antigens may be increased over that of the controls. Immune suppression develops gradually with duration of the infection. The significant drop of the CD4+:CD8+ ratio over a 5 week immunization period suggests that antigenic stimulation may accelerate the development of immune suppression in FIV positive cats. If this is a general feature, FIV infection may provide a particularly interesting model for studying the pathogenesis of AIDS.     

Melting curve analysis in canine lymphoma by calculating maximum fluorescence decrease

PARR is widely used in the diagnostics of canine lymphoma. In human and veterinary medicine, melting curve analysis (MCA) has successfully been introduced to facilitate the process. Since visual interpretation of melting curves can be rather subjective, the purpose of this study was to develop an objective interpretation of melting curves by calculating the maximum fluorescence decrease (dF_max) within a defined rise of temperature. Lymph node aspirates and blood of 34 dogs with lymphoma and 28 control dogs were tested. 27/34 lymphoma cases were correctly detected to be monoclonal (sensitivity 79%). 2/28 control dogs showed a monoclonal rearrangement (specificity 93%). B‐ and T‐cell neoplasia were still detectable using DNA amount as low as 10 ng. In serial dilutions of tumor DNA with DNA of normal tonsils, the detection limit was 25% for B‐cell lymphomas and 100% for T‐cell lymphoma, suggesting that PCR conditions could still be optimized.     

鸡皮刺螨引起产蛋下降的诊断与治疗

2007年6月，邢台县某养鸡场所饲养的一批高峰期产蛋鸡群鸡因发病产蛋率持续下降，虽经多个兽医诊治均未出现好转，并开始出现鸡只伤亡，经笔者进行检查，确诊为由鸡皮刺螨引起的寄生虫性传染病。通过采取有效治疗办法，鸡群明显好转，15日后产蛋率恢复正常。现将诊断与治疗情况报告如下：     

以追踪训练为抓手提高德国牧羊犬工作性能

德国牧羊犬以其忠诚、威猛、抗干扰、服从性好、易于训练而为人们所称道.在使用中,它更是一种全能的工作犬,其在刑侦、护卫、缉毒、搜爆等实际应用中的优秀表现已为实践所证实.追踪,是德国牧羊犬在刑侦等诸项使用中的最基础本领.一头训练有素的德国牧羊犬能够有效地跟踪地面上或空气中的嗅迹,并且在这个过程中,它还能战胜各种恶劣环境,直到达到目的.可以说,以追踪训练为抓手,是提高德国牧羊犬工作性能的最好途径.     

疫苗可降低球虫对药物的抗药性

研究结果证实球虫病疫苗可有效地取代田间虫株并且恢复对当前饲用抗球虫药的敏感性。     

Use of a crush-reducing device to decrease crushing of suckling piglets by sows

Weanling pigs tend to avoid wind, and suckling piglets are thought to be more sensitive to wind than weanlings, owing to their thinner s.c. fat layer. We developed a crush-reducing device based on the anticipated behavior of suckling piglets toward wind and evaluated the performance of the device through field testing. The crush-reducing device consisted of six photo sensors, a controller, six solenoid valves, and an air compressor. In this study, 206 sows and their suckling piglets (Landrace xYorkshire) were investigated to ascertain the individual effects of several factors. Some of the newborn piglets were cross-fostered before the crush-reducing device was implemented. Litter weights were measured on d 0 and 4 to determine the influence of the crush-reducing device on the weights of suckling piglets. The crushing of suckling piglets by sows was affected by season (P < 0.01) and litter size (P < 0.05), but not by the parity of the sows; however, the number of crushed piglets per litter was less (P < 0.01) in the crush-reducing device group (0.05 +/- 0.02 crushed piglets/litter) than in the control group (0.23 +/- 0.04 crushed piglets/litter), regardless of litter size or season. The BW gain of suckling piglets did not differ between the control and the crush-reducing device groups. Based on these results, the crush-reducing device is expected to decrease the number of crushed piglets per litter without influencing the BW gain of suckling piglets, thereby greatly contributing to the productivity of pig breeders.     

生物技术生产饲料添加剂植酸酶

一、植酸酶的来源 自1907年Suzuki等首次发现具有植酸酶活性的磷酸酶以来,有关植酸酶的认识不断深入。植酸酶在自然界中是早已存在的,只是在近些年来由于科技的进步,使得植酸酶的生产成本降低,有望在生产实践中得到应用,才引起了人们的广泛关注。     

原子吸收法测定蜂蜜中铅含量

研究原子吸收分光光度测定蜂蜜中铅含量的分析检测方法。实验表明,采用灰化法处理蜂蜜样品,用石墨炉原子吸收法测定蜂蜜的铅,精密度好,精确度高,能够满足日常分析要求。