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2145 Uppsatser om Genetic variation - Sida 1 av 143

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.

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.

Genetisk variation i säsongsbunden reproduktion hos får

The purpose of this literature study was to describe the seasonal reproduction in sheep and the presence of Genetic variation in fertility traits. Methods to induce oestrus are described and the possibilities to change the reproduction season through breeding are discussed. Sheep have a pronounced seasonality in their reproduction. Mating season starts in the fall and the lambs are born during the spring because this is the most beneficial time. The market request for lamb meat has increased and therefore it is desirable with ewes that could get pregnant all year round.

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.

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.

Kalvningsintervall hos svenska köttkor : finns det genetisk variation som kan användas i avelsarbetet?

The Swedish beef cattle population is growing when the dairy cattle become fewer. The fertility of the beef cows is important for the profitability in beef cattle production. Today there is no genetic evaluation for female fertility in Swedish beef cows. The purpose of this study was to see if calving interval can be used in the genetic evaluation as a measure of female fertility in beef cows. For this purpose the variation in calving interval for beef cows of different breeds and ages registred in KAP was studied.

Patellar luxation - a genetic study

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Analysis of MHC class II and monogenic eye diseases in the Scandinavian wolf population

ABSTRACT. In the late 1960?s all the wolves in Scandinavia went extinct in the wild due to extensive hunting. In 1983 two new wolves immigrated and founded, together with a third immigrant in 1991, the population that exists today. Due to the fact that the population originates from less than a handful of individuals, the Genetic variation is small.

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 variation in dairy cattle claw health traits recorded by claw trimmers

Claw health has been recorded by claw trimmers at trimming in Sweden since 1996, but data was then captured at each AI association. From 2003 data was captured by central scanning and entered directly to the national cow data base at the Swedish Dairy Association (SDA). This reporting was introduced because SDA wanted to be able to use these records to improve dairy cow claw health by breeding. It is desirable with cows that have healthy claws, because poor claw health can contribute to impaired production and fertility. The claw health report begins with some information about herd, claw trimmer, date et cetera and continues with the part where the claw health is recorded. Here the ID of each cow is filled in and on the same row the conditions for dermatitis, heel horn erosion, sole haemorrhage and sole ulcer are recorded as no lesion (blank), slight lesion (/) or severe lesion (X).

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.

Genetisk variation i brunststyrka hos svenska mjölkkor :

When cows in Sweden are inseminated the heat strength is reported to the Swedish milk-recording scheme and AI scheme. Cows that show strong signs of estrus are desirable and the trait is included in the Swedish breeding goal. A strong heat makes it easier to inseminate at the right time and to avoid long and expensive days open. Since ten years the heat strength is scored from one to five by the farmer and reported to the milk-recording scheme and AI scheme. Earlier the score was from one to three and the decision was made by the AI technician.

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