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分子育种及其在牦牛育种中的应用 总被引：3，自引：0，他引：3
随着分子遗传学、计算机科学、信息科学和现代生物技术的迅速发展,由分子遗传学与数量遗传学结合产生的新兴交叉学科——分子数量遗传学也得到了一定的发展,并为动物分子育种奠定了理论基础。与传统的动物育种方法相比,动物分子育种是直接在DNA水平上对性状的基因型或基因进行选择,因而其选种的准确性大大提高。同时,转基因技术的成功应用不仅可提高畜牧业的生产效率,还可拓展家畜的新用途。本文综合论述了分子育种及其在牦牛育种中的应用情况。 相似文献
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采用不同犊牛培育方法,考察对传统饲养条件、高效繁育技术条件下对后代公犊牛及育成种公牛生长发育的影响。研究结果表明:与传统对照组相比,犊牛培育组犊牛成活率、初选合格率、复选合格率和定选合格率分别为100.00%、95.00%、87.50%和80.00%,比传统对照组分别提高17.65%、26.67%、40%和60%,差异显著(P<0.05);与培育对照组相比,犊牛培育组的犊牛成活率、初选合格率、复选合格率和定选合格率分别提高5.27%、11.77%、12.91%和18.52%,差异显著(P<0.05)。采用犊牛培育技术,后代犊牛及育成牛生长发育各项指标较对照组明显增加,有效提高牦牛种公牛培育合格率,从而为大量生产优质牦牛种公牛提供一条切实有效的生产方式。 相似文献
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采用不同犊牛培育方法,分别考察对传统饲养条件和高效繁育技术条件下对后代公犊牛及育成母牛生长发育的影响。研究结果表明:与传统对照组相比,犊牛培育组犊牛成活率达到97.23%,犊牛培育组的成活率、初选合格率、复选合格率和定选合格率分别为91.67%、80.56%和77.78%,分别比传统对照组提高12.90%、13.79%、11.54%和27.26%,差异显著(P<0.05)。犊牛体高、体斜长、胸围、管围及体重显著提高,差异显著(P<0.05)。采用犊牛培育技术,后代犊牛及育成牛生长发育各项指标较对照组明显增加,有效提高牦牛种母牛培育合格率,从而为建立优良种母牛核心群提供一条切实有效的生产途径。 相似文献
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S. Gizaw B. Rischkowsky A. Valle‐Zárate A. Haile J.A.M. van Arendonk A.O. Mwai T. Dessie 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2014,131(5):341-349
Village‐ and central nucleus‐based schemes were simulated and evaluated for their relative bio‐economic efficiencies, using Ethiopia's Menz sheep as example. The schemes were: village‐based 2‐tier (Scheme‐1) and 1‐tier (Scheme‐2) cooperative village breeding schemes, dispersed village‐based nuclei scheme (Scheme‐3), conventional 2‐tier central nucleus‐based scheme (Scheme‐4), and schemes linking a central nucleus and village multiplier nuclei with selection in central nucleus (Scheme‐5) or in both central and village nuclei (Scheme‐6). Among village‐based schemes, Scheme‐1 gave the highest genetic progress, while Scheme‐2 was economically the most efficient with genetic gain in the breeding objective of Birr 5.6 and a profit of Birr 37.2/ewe/year. The central nucleus schemes were more efficient than the village schemes. Scheme‐4 was the most efficient with genetic gain in the breeding objective of Birr 13.5 and a profit of Birr 71.2, but is operationally more difficult as it requires a very large central nucleus. The choice between village and central nucleus‐based schemes would depend on local conditions (availability of infrastructure, logistics and technical knowhow and support). Linking central nucleus with village‐based nuclei (Scheme‐6) would be a feasible option to overcome the operational difficulties of the conventional central nucleus scheme. If a village‐based breeding program is envisaged as should be the 1st step in most low‐input systems, then Scheme‐2 is the most efficient. To scale out to an entire Menz breed level, Scheme‐3 would be recommended. 相似文献
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F. Sitzenstock I. Rathke F. Ytournel H. Simianer 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2013,130(3):199-208
A reference horse‐breeding programme with 13 500 foals each year was modelled with ZPLAN+. This new software for the optimization of the structures in breeding programmes is based on ZPLAN. In two scenarios, the implementation of a rigorous selection of mares was implemented. In scenario I, the mare performance test was the point of selection, while in scenario II, further information on 20 competitions in two more years is available. These selected mares were used for embryo transfer (ET), partly in combination with multiple ovulation (MOET). The selection intensity and the number of foals out of (MO)ET were varied in both scenarios. It was expected that 250, 500 and 1000 mares are available for selecting 20, 50, 100 or 200 donor mares each year. The number of foals out of (MO)ET was varied between one and six foals per donor mare and year. Donor mares were used for ET for 4 years. It became clear that with high selection intensities of donor mares and high reproduction rates of them, the yearly genetic gain in a horse‐breeding programme could increase over a large range. In scenario II, the additional information on 20 competitions increased the accuracy of the selection index to 0.85. With 200 selected donor mares of 1000 available mares and six foals per year, the genetic gain could almost be doubled compared to the reference scenario. The implementation of ET and a related higher usage of few selected mares entails rising costs and a reduction in the genetic variance. In the most extreme MOET scenario, the effective population size was reduced by 19% relative to the reference scenario. Only if the increase in genetic gain can be converted into higher return for the breeders, the implementation of (MO)ET schemes is a realistic and sensible option for horse‐breeding programmes. 相似文献
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统计中系马里努阿犬3个世代系谱资料和兴奋性状测试记录,对中系马里努阿犬兴奋性状不同的选育方法进行模拟研究。利用系谱资料,F3和F4世代兴奋性状数据,估算个体育种值,依据表型和育种值数据,对F4犬群按照个体表型、家系表型、个体育种值、家系育种值进行排序,各选择35%个体,筛选其在F5代中的个体,统计分析各种选择方法后代表型和遗传进展,评测不同选择方法对中系马里努阿犬兴奋性状选育最优方法。研究结果:选择中系马里努阿犬个体育种值好于选择家系育种值好于选择家系好于选择个体表型,选择中系马里努阿犬公犬效果好于选择母犬的效果。 相似文献
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Improving production efficiency in the presence of genotype by environment interactions in pig genomic selection breeding programmes 
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下载免费PDF全文 We simulated a genomic selection pig breeding schemes containing nucleus and production herds to improve feed efficiency of production pigs that were cross‐breed. Elite nucleus herds had access to high‐quality feed, and production herds were fed low‐quality feed. Feed efficiency in the nucleus herds had a heritability of 0.3 and 0.25 in the production herds. It was assumed the genetic relationships between feed efficiency in the nucleus and production were low (rg = 0.2), medium (rg = 0.5) and high (rg = 0.8). In our alternative breeding schemes, different proportion of production animals were recorded for feed efficiency and genotyped with high‐density panel of genetic markers. Genomic breeding value of the selection candidates for feed efficiency was estimated based on three different approaches. In one approach, genomic breeding value was estimated including nucleus animals in the reference population. In the second approach, the reference population was containing a mixture of nucleus and production animals. In the third approach, the reference population was only consisting of production herds. Using a mixture reference population, we generated 40–115% more genetic gain in the production environment as compared to only using nucleus reference population that were fed high‐quality feed sources when the production animals were offspring of the nucleus animals. When the production animals were grand offspring of the nucleus animals, 43–104% more genetic gain was generated. Similarly, a higher genetic gain generated in the production environment when mixed reference population was used as compared to only using production animals. This was up to 19 and 14% when the production animals were offspring and grand offspring of nucleus animals, respectively. Therefore, in genomic selection pig breeding programmes, feed efficiency traits could be improved by properly designing the reference population. 相似文献
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AIM: To estimate the heritability of the New Zealand Veterinary Association (NZVA) elbow phenotype, obtain estimated breeding values (EBV) for the worst-elbow score and estimate the genetic trends for this trait in four populous breeds of dogs, using the records from the NZVA Canine Elbow Dysplasia Scheme database (1992–2013).METHODS: Overall, 4,070 elbow records from a pedigree of 11,311 dogs were available for animals scored between 1992 and 2013. The worst elbow score between the left and right elbows was identified for each dog and used for EBV analysis. Estimates of heritability and EBV for the elbow score of dogs from German Shepherd dog, Labrador Retriever, Golden Retriever and Rottweiler breeds were obtained using restricted maximum likelihood procedures with a within-breed linear animal model. The model included the fixed effects of sex and birth year, with age at scoring as a covariable, and the random effect of animal. Genetic trends for the worst-elbow score were calculated as the regression coefficient of the EBV, weighted by reliabilities, on year of birth.RESULTS: The estimates of heritability for worst-elbow score were 0.25 (SE 0.06) in German Shepherd dogs, 0.46 (SE 0.06) in Labrador Retrievers, 0.18 (SE 0.07) in Golden Retrievers and 0.29 (SE 0.11) in Rottweilers. The genetic trend for German Shepherd dogs was ?0.0082 (SE 0.0015), for Labrador Retrievers was ?0.0016 (SE 0.0016), for Golden Retrievers was ?0.0033 (SE 0.0010) and for Rottweilers was ?0.0070 (SE 0.0023) units per annum, which were different from zero (p<0.01) in all breeds except Labrador Retrievers.CONCLUSIONS AND CLINICAL RELEVANCE: A small but favourable response to selection was achieved by three of the four breeds in the study period; during which selection for elbow traits has been largely voluntary. While the magnitude of genetic change in terms of elbow units per annum may appear small, it must be remembered that elbow scoring grades only range from 0–3. Greater improvement may be possible if compulsory screening was a requirement for pedigree breeding stock, and if greater selection pressure were applied on the basis on an individual’s EBV, rather than the worst-elbow score alone. The maintenance of an open registry, with transparency of EBV information made available to all breeders, may enhance selection intensity opportunities and potentially assist with the process and progress of breeding selection. 相似文献
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兰州市犬瘟热、犬细小病毒病及犬副流感的感染调查分析 总被引：2，自引：0，他引：2
为查清兰州市宠物犬犬瘟热、犬细小病毒病、犬副流感的感染情况,本研究对2004年~2009年前来宠物医院就诊的有临床症状的犬进行检测,共采集犬瘟热疑似病犬眼鼻分泌物、唾液2238份;犬细小病毒病疑似病犬粪便2423份;犬副流感疑似病犬眼、鼻分泌物334份。用快速检测试纸卡进行检测,结果显示兰州市宠物犬犬瘟热平均阳性率达27.52%,自2004~2009年间呈逐渐下降趋势。犬细小病毒病平均阳性率为25.88%,自2004~2008年间呈逐渐下降趋势,2009年略有反弹。首次证实犬副流感在兰州市宠物犬中流行,其中犬副流感病毒平均阳性率为37.72%,犬腺病毒Ⅱ型平均阳性率为19.46%,从流行周期看,2004年以犬副流感病毒感染为主,2005年以犬腺病毒Ⅱ型感染为主,而后连续两年以混合感染为主,到2008年又以犬副流感病毒感染为主,2009年再次以混合感染为主。 相似文献
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S.J. Viitanen A. Lappalainen M.M. Rajamäki 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(2):544-551
Background
Bacterial pneumonia (BP) is an inflammation of the lower airways and lung parenchyma secondary to bacterial infection. The pathogenesis of BP in dogs is complex and the role of canine respiratory viruses has not been fully evaluated.Objectives
The aim of this study was to investigate the occurrence of viral co‐infections in dogs with BP and to assess demographic or clinical variables as well as disease severity associated with viral co‐infections.Animals
Twenty household dogs with BP caused by opportunistic bacteria and 13 dogs with chronic (>30 days) tracheobronchitis caused by Bordetella bronchiseptica (BBTB).Methods
Prospective cross‐sectional observational study. Diagnosis was confirmed by clinical and laboratory findings, diagnostic imaging, and cytologic and microbiologic analysis of bronchoalveolar lavage or transtracheal wash fluid. Canine parainfluenza virus (CPIV), canine adenovirus, canine herpes virus, canine influenzavirus, canine distemper virus, canine respiratory coronavirus (CRCoV) and canine pneumovirus, as well as B. bronchiseptica and Mycoplasma spp. were analyzed in respiratory samples using PCR assays.Results
CPIV was detected in 7/20 and CRCoV in 1/20 dogs with BP. Respiratory viruses were not detected in dogs with BBTB. There were no significant differences in clinical variables between BP dogs with and without a viral co‐infection.Conclusion and Clinical Importance
Respiratory viruses were found frequently in dogs with BP and may therefore play an important role in the etiology and pathogenesis of BP. Clinical variables and disease severity did not differ between BP dogs with and without viral co‐infection. 相似文献18.
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Objective
To determine whether dogs with spontaneously-occurring diabetes mellitus demonstrate serological reactivity to proinsulin.Sample population
Serum samples were collected from 15 newly-diagnosed diabetic, 15 insulin-treated diabetic and 15 non-diabetic control dogs.Procedures
Canine proinsulin was cloned into a prokaryotic expression vector to generate recombinant poly-histidine-tagged protein in Escherichia coli. A Western blotting assay was developed for detection of proinsulin autoantibodies in canine sera.Results
Reactivity to canine proinsulin was detected in 3 of 15 control dogs, 8 of 15 newly-diagnosed diabetic dogs and 6 of 15 insulin-treated diabetic patients. Of these reactors, only 1 control dog, 1 newly-diagnosed diabetic dog and 3 insulin-treated diabetic dogs recognised porcine insulin by ELISA, suggesting that the remaining proinsulin reactors might have been recognising proinsulin-specific epitopes.Conclusions and clinical relevance
This study suggests that proinsulin autoantibodies are present in a proportion of diabetic dogs. Further work is required to refine the assay and clarify the significance of these autoantibodies. 相似文献20.
Bodil Str?m Holst Karin L?fqvist Linda Ernholm Karin Eld Maria Cedersmyg Gunilla Hallgren 《Acta veterinaria Scandinavica》2012,54(1):18
Infection with Brucella canis has been diagnosed in Sweden for the first time. It was diagnosed in a three-year-old breeding bitch with reproductive disturbances. Fifteen in-contact dogs were tested repeatedly and all of them were negative for B. canis. The source of infection could not be defined. The present article describes the case and the measures undertaken and gives a short review over B. canis. Recommendations on how to avoid the infection in non-endemic countries are given. 相似文献