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1482 Uppsatser om Genetic gain - Sida 1 av 99

Genomisk selektion inom köttraser

Genomic selection (GS) is used for selection of breeding animals of dairy cattle. GS is though not as extensively used within the beef industry. One reason for that is the low accuracy (rTI) of the breeding value that is of great importance for the final Genetic gain. Causes to the low accuracy are high effective population size, a small reference population and a genetically differentiated population. There is however a market for genomic selection with High Density (HD) tests for beef cattle.

Genomisk selektion och uppbyggnaden av avelsprogram hos mjölkkor

During the last decade a new technique in animal breeding has developed called genomic selection. It is based on estimations of the effect from genetic markers on traits that are calculated in a reference population. By genotyping individuals, genomic breeding values can then be estimated without phenotypic observations. The aim of this essay is to investigate the response of genomic selection on breeding schemes for dairy cattle. The accuracy of the genomic breeding values is affected by the proportion of observations included in the validation set and how often the equation for estimating breeding values is reevaluated.

Genetiska defekter hos nötkreatur :

Genetic defects are caused by mutations in major genes where the gene?s protein product has a large impact on the physiology of the animal. The synthesis of the protein can be altered by a change in the nucleotide sequence, which can lead to malformation and in many cases death.One of the main reasons of increase in many genetic defects is the use of few bulls in breeding programmes, causing a reduction of the genetic variation. Genetic defects cause suffering for the animal and influences the production by, for example, increased costs due to misscarriages, lost milk production and expenditure for medical treatment. Bovine Leukocyte Adhesion Deficiency (BLAD) and Complex Vertebral Malformation (CVM) are two genetic defects that were widespread before the causative mutation was discovered.

Patellar luxation - a genetic study

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Population genetic analysis and breed assignment of three Swedish horse breeds

The genetic relationship between three Swedish horse breeds was investigated using microsatellite data from 144 loci in 30 horses. The North Swedish Trotter is believed to have been crossed with the Standardbred in the 1950?s to produce a faster trotter. If true, the North Swedish Trotter should be more alike the Standardbred than what the North Swedish Draught Horse is, from which they originate. This was investigated using F-statistics and Nei?s distance in GENEPOP and GENETIX and cluster assignment in STRUCTURE.

Genetic diversity of Roseroot (Rhodiola rosea L.) from Sweden, Greenland and Faroe Islands

Roseroot (R. rosea L.) has gained more attention the last years, mainly because of its phy-topharmacologic properties. Even though many reports in roseroot have been published, only a few articles are dealt with the genetic diversity. The Nordic Genetic Resource Center has collected Roseroot material from Sweden, Greenland and Faroe Islands under different expeditions. The samples were analysed to study the genetic diversity study.

Genetiska ultraljudsmarkörer : Hur bör information till blivande föräldrar i samband med rutinultraljudet hanteras?

Objective: The purpose of the study is to explore and illustrate how ultrasound midwives and medical specialist in obstetrics and gynecology believe the information given to parents about the genetic soft markers should be handled.Design: A quantitative questionnaire study with cross-sectional design. Participants: 44 ultrasound midwives and 37 medical specialists in obstetrics and gynecology.Findings: Most of the participants would like to inform before the ultrasound starts that they will be looking for genetic softmarkers during the ultrasound. Likewise the majority wanted to inform the parents about possible increases in the risk for chromosomal abnormalities based on findings on the routine ultrasound. There was a difference in frequency between those who responded that they would like to inform before the ultrasound that they will be looking for genetic softmarkers and those who responded that they believe the future parents wants information before the examination.Key conclusions: It could help health care professionals in their role as information providers if there were common recommendations for the information to be given to future parents about genetic softmarkers in connection with the routine ultrasound.

Förvildade husdjur : möjligheter och hot

Feral animal populations are distributed over many parts of the world and are often seen as a problem. Since they are a threat against other species, destroy farmlands and can spread dis-eases, they are often referred to as pests. Artificial selection has contributed to loss of genetic diversity in our domesticated animals. Feral animal populations are affected by natural selec-tion, which allows them to adapt to the environment. Their ability to adapt is a reason to see them as pests but can also be seen as an asset.

International and national genetic evaluation of beef cattle : validation of national genetic evaluation models

After a workshop in Kuopio held in June 2006, Interbull decided to go forward with the development of a system for beef international genetic evaluation and a three year project called Interbeef was launched in June 2007. The participating countries are so far limited to Europe and the only trait evaluated at present is adjusted weaning weight (weight at 200 days). The results from a first international genetic evaluation have been shared with the countries but are not yet official. The evaluation is based on data from purebred Charolais and Limousin. To achieve good estimates of proofs in an international context it is important that methods for data validation and model selection are implemented.

Genetic variation in local Swedish sheep breeds

Sheep have played a very important part in rural history. In Sweden there were many kinds of small native breeds, kept for their meat and fleece. Women cared for the flock that often had very little to feed on during the cold and sometimes harsh winter months. This meant that these sheep over time acquired special phenotypic properties depending on the environment they lived in, and easily fed compared to modern breeds kept for meat. Most of these sheep have since become extinct.

Förekomsten av den genetiska varianten laktapersistens hos neolitiska grupper från Öland : The contribution of the genetic variant Lactase persistence among Neolithic people from the Baltic island Öland in Sweden

This study deals with the contribution of the genetic variant lactase persistence among Neolithic people from the Baltic Island Öland. Skeletal remains from twelve individuals went through DNA sequencing in order to find the mutation that allows adult individuals to digest milk sugar. The twelve individuals were chosen from two different Neolithic sites, where the archaeological and isotopic data suggest that the individuals from Köpingsvik were hunters and gatherers and the individuals from Resmo were early farmers. The individuals with the genetic variant lactase persistence can be described with selection and genetic flow.  Only five individuals produced results and the mutation was found in two of the subjects. All the individuals who were successfully sequenced came from Resmo, whereasno individuals from Köpingsvik yielded any results.

Arvets betydelse för mjölkkors beteende :

It becomes more important to consider different behaviour traits in the selection for dairy cows to be suitable in the production systems of today. The purpose of this investigation was to study the genetic background to behavioural traits and the heritabilities for temperament, rank order, aggressiveness, feeding behaviour and for learning behaviour. Moreover, the genetic correlations to other traits were studied. To be included in a breeding programme a trait needs to have enough genetic variation, a moderate to high heritability or to be correlated to another measurable trait. Behaviour is a quantitative trait affected by many genes and the environment.

Användning av könssorterad sperma i nötkreatursaveln :

Almost for as long as there has been breeding on bovine species, there has been a wish to have a higher proportion of offspring of either one or the other gender. In dairy cattle, heifers are more valuable, while in beef stock bulls are preferred. Semen is sorted based on the difference in DNA content between the X- and Y-chromosome in the genome of the sperm. X-chromosomes contain on average between 3,70 to 4,22% more genetic material than the Y-chromosome. Commercially it is the method of flow cytometry that is being used, which is always under improvement.

Privatiseringen av de växtgenetiska allmänningarna : Konsekvenserna av regimkomplexet kring växtgenetiska resurser för bönders rättigheter och matsäkerhet

This thesis discusses the global regime complex concerning the management of plant genetic resources for food and agriculture, and how different regimes concerning these resources cooperate or stand in opposition to each other. Because of changes in US patent law and the establishment of TRIPS, patent claims over plant genetic resources has increased dramatically globally. This, amongst other things, in turn has lead to the development of CBD which in turn lead to the creation of access and benefit laws in many countries. To create a free flow of genetic resources for food and agriculture the ITPGRFA, with its multilateral system, were negotiated. The aim of this thesis is to investigate which consequences the regime complex concerning plant genetic resources for food and agriculture can have on the rights of small farmers, agricultural research and food security in the global South.

Bevarande av de svenska lantraserna, populationsgenetiska och molekylärgenetiska metoder

Today?s community requires an increase in food production. Animals are today bred so that they produce more than their ancestors did. Production has been the most important and breeds with the highest production levels have therefore become popular. Many of the old local breeds have become extinct or are about to become extinct because of this trend.

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