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31.
Thinh Tuan Chu John W.M. Bastiaansen Elise Norberg Peer Berg 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(1):1-10
To improve genetic gain of breeding programs for village poultry production, breeding schemes with observations obtained in village production systems using individual (VIO) and group recording (VGO) were examined under different levels of genotype-by-environment-interactions (GxE). GxE was modeled by varying the correlation between traits measured in the breeding station and village environments for bodyweight (rg_BW) and egg production (rg_EP). Relative and absolute genetic gains obtained from VIO and VGO were used for comparison between the schemes. Results showed that village observations significantly improved genetic gains compared to the scheme without birds tested in the village. The improvement was only slightly larger with individual observations than with group observations. Higher rg_BW and rg_EP led to lower relative genetic gain, but a higher absolute gain of VIO and VGO. It is recommended to apply a breeding scheme using group recording of village performance when strong GxE in breeding for village poultry is expected. 相似文献
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D M Hawks A M Legendre B W Rohrbach R Sebring L Chavez H J Chu W M Acree 《Journal of the American Veterinary Medical Association》1991,199(10):1463-1469
Protein (western) blot analysis and virus-neutralization assay were used to evaluate the antibody response of specific-pathogen-free kittens to FeLV vaccination and followed by natural exposure. Several kittens had barely detectable reactions to specific FeLV antigens prior to vaccination or exposure. Correlation was not found between protection against persistent viremia and antibody response after vaccination as measured by western blot analysis or virus neutralization assay. A statistically significant (P less than 0.01) difference in the antibody response against p27 antigen after natural exposure to FeLV was observed between persistently viremic kittens and transiently viremic or aviremic kittens. Measurable (P less than 0.05) virus neutralizing antibody titer after FeLV exposure was found only in a small number of kittens that were protected against persistent viremia. Lack of association between humoral response and vaccination-induced protection against persistent FeLV infection suggests an important role for cell-mediated immunity in such protection. 相似文献
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A micromethod employing the neutralisation and direct immunofluorescence technique for the detection of antibodies against swine fever in pig serum samples is described. The micromethod is simple and reproducible when compared with the macromethod. A total of 80 blood samples were randomly collected for comparison. The results are promising and reveal a 100 per cent correlation with the macrotechnique. 相似文献
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Enzyme-linked immunosorbent assay for the detection of antibodies to bovine virus diarrhea virus in sera from border disease virus-infected sheep. 下载免费PDF全文
H J Chu M M Sawyer C A Anderson R J Higgins Y C Zee 《Canadian journal of veterinary research》1987,51(2):281-283
An enzyme-linked immunosorbent assay (ELISA) was established for the rapid detection of specific antibodies against the causative agent of border disease in ovine sera. Polyethylene-glycol concentrated, equilibrium density gradient purified bovine virus diarrhea virus was used as test antigen. The optimal amount of antigen was 0.5 microgram/well, and the optimal concentration of conjugate was at 1/4,000 dilution. A total of 20 ovine serum samples, which had been collected from animals with or without border disease, were compared by ELISA and serum neutralization test for the detection of border disease-specific antibodies. ELISA was shown to be equally specific but less time-consuming and easier to perform than serum neutralization test. A positive correlation (r = 0.60) between the two tests was found. 相似文献
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Nhung Thi Nguyen Nguyen Xuan Bui Viet Linh Nguyen Van Khanh Nguyen Kazuhiro Kikuchi Hiep Thi Nguyen Hong Thi Nguyen Hoang Thinh Nguyen Quyen Van Dong Hoang Ha Chu Ngo Thi Kim Cuc Tamas Somfai 《Animal Science Journal》2020,91(1)
The Vietnamese Ban pig is a precious genetic resource that needs to be preserved. In vitro embryo production from in vitro matured (IVM) oocytes is an important tool for the utilization of cryopreserved porcine sperm. The aim of this study was to compare two media for the IVM of Ban pig oocytes. Immature oocytes were subjected to IVM either in a non‐defined (TCM‐199 + pig follicular fluid) or in a defined base medium (POM + epidermal growth factor). At the end of IVM, the oocytes were in vitro fertilized (IVF) with frozen Ban sperm. Ten hours after IVF, the oocytes were either subjected to orcein staining to check fertilization and maturation status or cultured in vitro for 7 days. There was no difference between the two IVM media in terms of percentages of oocyte maturation and blastocyst production. However, the percentage of male pronuclear formation after IVF and the total cell numbers in blastocysts were higher with the defined system. Zygotes obtained by the two IVM systems survived vitrification at similar rates. In conclusion, the two IVM systems were both effective for the production of Ban pig embryos; however, better embryo quality was achieved with the defined one. 相似文献
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本研究提取了艾比湖湿地不同年份(1998、2007、2011、2014年)的NDVI指数,并进行了实地考察,然后利用像元二分模型对研究区植被覆盖状况进行估算,并分析其在时空分布上的特征及形成原因,建立影响植被覆盖与微气候变化的线性回归模型。结果表明,1)在空间分布上,西南部冲积平原植被覆盖等级最高,东北部覆盖等级略低于西南部,无覆盖和低覆盖等级分布面积最为广泛;在时间分布上,无覆盖面积处于下降趋势,低覆盖和中覆盖面积有所增加,较高覆盖与高覆盖等级面积处于下降趋势;2)不同植被覆盖度对气候变化的响应存在一定的差异;植被覆盖对降水量变化的反应最为强烈,在时间上具有一定的滞后性,对湿度变化的响应不明显,气温与植被覆盖水平之间存在线性函数关系。 相似文献