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1.
Modern biotechnology promises a number of new applications in animal breeding and production. Although conventional pig breeding has achieved a high level of efficiency and productivity numerous problems have been encountered with animal health and the loss of meat quality. Selection based on phenotypic performance data of individual animals does not take into account the importance of specific genes and their relevance within a complex regulatory system. In most cases it is therefore difficult to trace back the genetic origins of clinically important disorders. The application of genetic engineering techniques in pig production will facilitate diagnosis, improvement of productivity, and animal health by allowing direct genetic manipulation. Attention must be focussed on the physical and genetic analysis of the procine genome. The isolation and characterisation of genes, DNA-markers, polymorphic DNA-fragments, and their chromosomal assignment will be important prerequisites and tools for the elucidation of genetic disorders. Especially the detection of heterozygous carriers of recessive disorders and their elimination from the breeding stock will increase selection accuracy and decrease the generation intervals. But also the rapid and simple detection of infectious diseases, which is sometimes difficult if not impossible at present, will improve animal health and welfare. Although the production of transgenic animals either by DNA-microinjection into zygotes or the use of embryonal stem cells manipulated in vitro is less straightforward than DNA-based diagnosis it will play an important role in the direct manipulation of the porcine genome and genes. Breeding programmes including the use of transgenic livestock have already been developed. There is no doubt that genetic engineering has reached a degree of practical feasibility, allowing it to play an important role in pig breeding in particular and animal production in general. 相似文献
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万峰山自然保护区地处地貌发育典型的喀斯特地区,是我国滇东喀斯特山地森林的重要组成部分,也是滇东地区重要的物种基因库。本文在对保护区内现有野生动植物资源进行分析的基础上,从典型性、稀有性、脆弱性、多样性、感染力、面积适宜性、潜在价值、科研价值等方面对保护区的保护价值进行了综合评价分析,认为保护区形成了具有代表性的喀斯特山地森林生态系统,区内的森林生态系统对保护喀斯特地区极其脆弱的生态环境及保护生物多样性具有十分重要的意义。 相似文献
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Chelsea M. Kunst Anthony P. Pease Nathan C. Nelson Greg Habing Elizabeth A. Ballegeer 《Veterinary radiology & ultrasound》2014,55(5):511-520
Elbow dysplasia is a heritable disease that is a common cause of lameness and progressive elbow osteoarthritis in young large breed dogs. The Orthopedic Foundation for Animals (OFA) screens elbow radiographs, and assigns grades 0–3 based on presence and severity of bony proliferation on the anconeal process. Grade 1 is assigned when less than 3 mm is present and considered positive for dysplasia. We investigated the incidence of elbow dysplasia and progression of osteoarthritis in elbows with grades 0 and 1 in 46 elbows screened at least 1 year previously, using CT as a gold standard and with the addition of CT absorptiometry. The incidence of dysplasia based on CT was 62% in grade 0, and 75% in grade 1 elbows, all of which had medial coronoid disease. Progressive osteoarthritis at recheck was consistent with elbow dysplasia. The sensitivity and specificity of the OFA grade for elbow dysplasia compared to CT findings was 75% and 38%, respectively. Increased bone mineral density of the medial coronoid process as characterized by osteoabsorptiometry warrants further investigation with respect to elbow dysplasia. Proliferation on the anconeal process without CT evidence of dysplasia or osteoarthritis was present in 20% of the elbows, and is theorized to be an anatomic variant or enthesopathy of the olecranon ligament/synovium. Results of our study suggest that the “anconeal bump” used for elbow screening by the OFA is a relatively insensitive characteristic, and support the use of CT for identifying additional characteristics of elbow dysplasia. 相似文献
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超氧化物歧化酶(SOD)具有防止细胞过度氧化的生理功能,从海洋生物中提取的SOD,可用于清除运动产生的自由基,起到抗疲劳作用.本文探讨了SOD抗疲劳作用的动物实验方法,为验证SOD抗疲劳效果建立技术平台. 相似文献
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Arginine (ARG) exerts many beneficial effects on animal body and enhanced angiogenesis, lactogenesis, which finally leads to the improvement in nitrogen (N) metabolism, reproduction, lactation, immunity and growth. Unfortunately, unprotected ARG will be degraded in the rumen and its price is high, thus feeding rumen-protected ARG seems to be uneconomical. Alternatively, N-carbamoyl glutamate (NCG) is structural analogue of N-acetyl glutamate, cofactor of cabamoyl phosphate synthetase1, is lower in rumen degradation compared to ARG. Additionally, rumen epithelial and duodenal cells have potentially utilized the NCG for ureagenesis. Supplementation of NCG to high yielding dairy cows increased plasma concentration of ARG and nitric oxide, decreased the plasma ammonia N and improved lactation performance and N utilization. Supplementation of NCG enhanced pregnancy rates in rats, improved litter size and fetal survival rate, thereby improved the reproductive performance of sows. Oral NCG supplementation increases plasma ARG and somatotropin levels, and increased growth rate and muscle protein synthesis in nursing piglets. The NCG is potential a relatively cheaper source of feed additive to offer vital compensation over oral administration of ARG, resulting in improved ruminant animal health and production. In this article, we reviewed the mechanism of ARG biosynthesis by NCG and their significance in growth, reproduction, milk production and N utilization in ruminant animals. 相似文献
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Paolo Borghetti Roberta Saleri Eugenio Mocchegiani Attilio Corradi Paolo Martelli 《Veterinary immunology and immunopathology》2009,130(3-4):141-162
The Central Nervous (CNS) and Immune Systems (IS) are the two major adaptive systems which respond rapidly to numerous challenges that are able to compromise health. The defensive response strictly linking innate to acquired immunity, works continuously to limit pathogen invasion and damage. The efficiency of the innate response is crucial for survival and for an optimum priming of acquired immunity. During infection, the immune response is modulated by an integrated neuro-immune network which potentiates innate immunity, controls potential harmful effects and also addresses metabolic and nutritional modifications supporting immune function. In the last decade much knowledge has been gained on the molecular signals that orchestrate this integrated adaptive response, with focus on the systemic mediators which have a crucial role in driving and controlling an efficient protective response. These mediators are also able to signal alterations and control pathway dysfunctions which may be involved in the persistence and/or overexpression of inflammation that may lead to tissue damage and to a negative metabolic impact, causing retarded growth.This review aims to describe some important signalling pathways which drive bidirectional communication between the Immune and Nervous Systems during infection. Particular emphasis is placed on pro-inflammatory cytokines, immunomodulator hormones such as Glucocorticoids (GCs), Growth hormone (GH), Insulin-like Growth Factor-1 (IGF-1), and Leptin, as well as nutritional factors such as Zinc (Zn).Finally, the review includes up-to-date information on this neuroimmune cross-talk in domestic animals. Data in domestic animal species are still limited, but there are several exciting areas of research, like the potential interaction pathways between mediators (i.e. cytokine-HPA regulation, IL-6-GCS-Zn, cytokines-GH/IGF-1, IL-6-GH-Leptin and thymus activity) that are or could be promising topics of future research in veterinary medicine. 相似文献