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971.
Kazuhiro Kawai Tomohito Hayashi Yoshio Kiku Tomoyuki Chiba Hajime Nagahata Hidetoshi Higuchi Tetsu Obayashi Seigo Itoh Ken Onda Sachiko Arai Reiichiro Sato Toshio Oshida 《Animal Science Journal》2013,84(12):805-807
Somatic cell counts (SCC) measurements are typically performed using quantitative methods, such as the Breed method (Breed) and the Fossomatic method (FSCC). The DeLaval cell counter (DCC) developed recently is a quantitative somatic cell counter with a low initial cost and superior portability. However, since the DCC was specifically developed for measuring SCC of ≤ 4 × 106 cells/mL milk from bulk tanks or individual cows, its reliability for estimating SCC that exceed this concentration has not yet been clarified. This study therefore examined whether it is possible to accurately measure SCC by diluting milk samples with initial SCC of 4 × 106 cells/mL, as seen in clinical mastitis milk. We collected milk samples from 99 quarters of 99 Holstein cows with clinical mastitis. These milk samples were diluted 10‐fold with saline and thoroughly mixed before performing SCC measurement with the DCC. The correlation coefficients of SCC measured by the FSCC, Breed and DCC methods indicated strong correlations between each pair of methods. The findings showed that DCC can be used to identify bovine clinical mastitis milk and is useful as a quantitative SCC measurement device on farm sites. 相似文献
972.
Shinya Watanabe 《Animal Science Journal》2013,84(9):631-638
To increase public understanding on cloned cattle derived from somatic cell nuclear transfer (SCNT), the present review describes the effect of calf death loss on an SCNT cattle herd. The incidence of death loss in SCNT cattle surviving more than 200 days reached the same level as that in conventionally bred cattle. This process could be considered as removal of SCNT cattle with congenital defects caused by calf death loss. As a result of comparative studies of SCNT cattle and conventionally bred cattle, the substantial equivalences in animal health status, milk and meat productive performance have been confirmed. Both sexes of SCNT cattle surviving to adulthood were fertile and their reproductive performance, including efficiency of progeny production, was the same as that in conventionally bred cattle. The presence of substantial equivalence between their progeny and conventionally bred cattle also existed. Despite these scientific findings, the commercial use of food products derived from SCNT cattle and their progeny has not been allowed by governments for reasons including the lack of public acceptance of these products and the low efficiency of animal SCNT. To overcome this situation, communication of the low risk of SCNT technology and research to improve SCNT efficiency are required. 相似文献
973.
974.
In order to elucidate the taxonomic status of the melanistic, girdled lizard, Cordylus cordylus niger, occurring in the Cape Peninsula and the Saldanha Bay area, South Africa, character variation among populations of the C. cordylus complex in the section of the Cape Province south of 32°3C latitude and west of 19°30' longitude was analysed. Variation for 92 external morphological characters at 54 localities was determined. Distinct patterns of interlocality variation were observed in only eight characters, but interestingly, these patterns were concordant in all eight cases. The observed patterns are interpreted as indicating that three phenotypic forms of the nominate species occur in the south-western Cape, namely a coastal melanistic form (= C. c. niger), occurring in insular and peninsular situations along the coast; a montane melanistic form occurring at relatively high altitudes along the western section of the Cape Fold Mountains; and the typical form (= C. c. cordylus), occurring commonly along the coastal lowlands, but also further inland at some places. 相似文献
975.
猪雄性生殖干细胞的分离培养及鉴定 总被引:1,自引:0,他引:1
本试验旨在探索猪雄性生殖干细胞(mGSCs)体外分离、培养的适宜条件,建立猪雄性生殖干细胞体外培养体系。采用两步酶消化法对新生小猪睾丸生殖干细胞进行了体外分离和初步的培养鉴定,并利用层黏连蛋白和明胶的不同贴壁特性,比较2种差易贴壁分选方法的富集效果,并对传代后的干细胞培养1周后进行碱性磷酸酶染色鉴定,通过免疫荧光技术检测培养细胞是否表达干细胞标志蛋白OCT-4。试验结果表明,层黏连蛋白更适用于猪生殖干细胞的富集、培养,细胞分选效率及增殖生长明显优于采用明胶分选的方法。培养的mGSCs拥有与小鼠mGSCs相同的形态、增殖及表达特征。鉴定结果显示,生长细胞克隆碱性磷酸酶染色呈阳性,支持细胞碱性磷酸酶染色呈阴性;培养的生殖干细胞克隆表达转录蛋白OCT-4,而饲养层支持细胞OCT-4抗体染色则呈阴性。结果表明培养的干细胞克隆仍保持较好的干细胞活性,保持正常的自我复制和分化潜能,初步建立了生殖干细胞培养体系。 相似文献
976.
通过将猪细小病毒CG-05株同步接种于ST细胞,测定不同时间收获的病毒液的TCID50和HA,研究了CG-05株病毒在ST细胞上的增殖规律。病毒接种后镜检观察接毒细胞,在接种病毒后24 h,即可在细胞较少的区域看到非常轻微的病变。测定病毒TCID50,检测到接毒后培养17h病毒已经明显增殖;当培养到40h左右,其TCID50即接近高峰,达到10-7.2/0.1mL以上,并进入平台期;继续培养,TCID50最高可达到10-8.5/0.1mL,且直到122 h也不见明显降低。病毒HA价也出现同样的平台期,但比TCID50的平台期出现得晚,到50 h才进入平台期。结果表明,用ST细胞培养CG-05株病毒,接种病毒培养56~96 h后,如病变达到80%以上,且细胞脱落已形成20%以上空斑,此时收获病毒可获得高效价的病毒液。该研究可为制备高效价的PPV病毒抗原提供数据资料。 相似文献
977.
用密度为5×106个/mL左右的BHK21悬浮细胞为实验原料,在2~8℃条件下静置保存,分别在24、48、72、96 h取样并计数,绘制细胞密度和细胞活力的曲线图,并进行统计学分析.在整个试验培养阶段细胞保持良好状态,趋势线呈平行直线,细胞密度和细胞活力均没有下降.说明BHK21悬浮细胞在2~8℃条件下,在96 h内短期保存时,细胞未出现活力降低或死亡的现象. 相似文献
978.
979.
Summary Since 1983 some pig breeding and fattening farms in the Netherlands have been faced with a considerable mortality in pigs due to Streptococcus suis type 2 infections. The most predominant clinical feature of S. suis type 2 infection is meningitis, although sudden deaths often occur. It was noted that some affected farms had imported breeding stock from the United Kingdom. Tonsils of slaughter pigs were collected from herds with and without a history of S. suis type 2 infections. Bacteriological examination was done by using an elective‐selective medium. No significant difference was found in carrier rates of S. suis type 2 between clinically healthy and affected herds (38% vs. 45%). A cohort study was carried out by regular bacteriological examination of tonsil biopsies on a farm with a high incidence of streptococcal meningitis. Twenty‐seven percent of the pigs were carriers of S. suis type 2 at nine weeks of age. Possible methods for disease control are discussed. 相似文献
980.
E. J. Pluimers 《The Veterinary quarterly》2013,33(2):82-89
Summary In a trial involving 542 dairy cattle on 28 farms, 276 were treated once with thiabendazole within two days of calving. The treated group showed an average increase in milk yielded over the non‐return group of 229.8 kg during the subsequent lactation. In the treated group, total milk fat production was increased over that of the controls by 7.4 kg per cow; milk protein was increased by 6.9 kg per cow. All treatment parameter differences were highly significant at the 1% level of probability. 相似文献