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359 Uppsatser om Genetic variance - Sida 3 av 24

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.

SAMMANS?TTNING AV MAKROALGER I SVENSKA ?LGR?S?NGAR eDNA sp?rning och klimatf?r?ndringar

The aim of my bachelor?s thesis is to investigate, through a literature review, changes in the distribution of filamentous algae as well as the general species composition of macroalgae and diatoms in Swedish eelgrass meadows. I have also studied the possibility of tracking these algae and diatoms in eelgrass meadows using eDNA methodology. The focus has been on linking these changes to climate change factors such as eutrophication, temperature increase, and anthropogenic emissions, and how these affect the health of eelgrass meadows and their ecosystem services, such as a carbon sink and biodiversity support. The results show that filamentous algae have increased markedly in coverage in Swedish coastal areas between 1980 and 2021, especially in sheltered bays, indicating that altered environmental conditions favor these fast-growing species. Genetic tracking using eDNA demonstrated that there are functional primers for many species, particularly among brown algae and red algae, whereas green algae require more specific primers due to greater genetic variation.

Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest :

More than 1000 Swedish Warmblood foals are shown every year at foal inspections which are arranged around the country. Six traits are evaluated at these inspections: type, head-neck-body, correctness of legs, walk, trot and canter. No previous genetic studies have been done on the data from these evaluations. The purpose of this study was to do genetic analyses of the traits which are evaluated at foal inspections. The purpose was also to see if there are any correlations between the results of the foal inspections and the results from the tests of three-year-old horses.

Alternativa index - En studie av mean-variance-effektiviteten hos index baserade på fundamentalvärde kontra börsvärde

Finansiella index är viktade genomsnitt av olika tillgångars avkastning från en bestämd tidpunkt. Traditionella index är börsvärdeviktade. Problemet med denna typ av index är att börsvärdet tidvis kraftigt kan överdrivas på grund av spekulation. Alternativa index bygger på företags fundamentalvärden. De viktas därmed efter företags faktiska redovisade siffror i balans- och resultaträkningar.

The genetic background of oxytocin and its importance for maternal behaviour of sows

Oxytocin is today widely spoken of as a "feel good" hormone. Recent research has increased interest in the hormone and its role in social and sexual interactions, as well as its importance for complex behavioral patterns. There is evidence that oxytocin is released during physical contact and is said to suppress anxiety and stress. In animals and humans, oxytocin, which is a neuropeptide and likewise a hormone, is necessary for parturition and lactation. Synthesis of oxytocin occurs in brain neurons and in specific organs involved in reproduction.

Genetic parameters affecting leg length, leg weakness, hip- and elbow conformation in domesticated dogs, in comparison with pigs

Genetic parameters for four leg conformation traits in dogs (Canis lupus familiaris) are in this literature review summarized to investigate whether selective breeding could be useful to improve purebred dogs´ health and welfare. The four traits are leg length, leg weakness, hip joint and elbow joint conformation. When summarized, the genetic parameters are compared with genetic parameters affecting in pigs (Sus scrofa). Of the four traits, hip and elbow conformations were mostly studied in dogs. However, these traits were not widely studied in pigs.

När och varför dör smågrisarna under diperioden?

The purpose of this study was to compile when and why piglets die during the suckling peri-od. Piglet mortality is an important factor influencing the profitability of piglet production. There are many factors that play a role and interact whit each other. This study summarizes when the piglets die during the suckling period and reasons why the piglets die. The infor-mation given is crushed, illness, management/environmental, genetic influence and piglet birth weight/farrowingprocess.

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).

Latitudinal patterns in body size of Roesel?s bush cricketMetrioptera roeselii within and outside the continuous area of its distribution

Over time, species colonize new areas naturally or through humans. The colonizers areoften few and founded populations represent only a fraction of the genetic diversityexisting in the original population. If the established population becomes isolated afterthe colonization event genetic diversity will remain low and if the population, in addition,remains small in size for an extended period this will lead to increased inbreeding andpossibly inbreeding depression. Metrioptera roeselii is a common species with awidespread distribution in continental Europe. During the last century, it has expanded tothe Scandinavian Peninsula which is separated from continental Europe by the Baltic Sea.My aim was to test the hypothesis that individuals in isolated populations in Scandinaviaincluding Denmark and the Baltic Sea islands are smaller than individuals in thecontinuous part of its distribution due to low genetic diversity and lacking incoming geneflow.

Artificiell insemination av får

AbstractThe purpose of this bachelor thesis is to describe the use of artificial insemination (AI) in sheep and discuss the possibilities for AI in Sweden. Male and female fertility, heat detection, semen handling and insemination techniques in sheep are described. Advantages and disadvantages of AI are discussed. In order to achieve genetic progress it is important with well planned and implemented breeding programs. The Swedish Sheep Recording Scheme and computer software from Elitlamm are the basis for sheep breeding in Sweden.

Läsförmågans faktorer och deras bidrag till läsning : En jämförelse mellan barn med olika nivå av läsförmåga, utifrån The Simple View of Reading

The simple view of reading is a theory in which reading is divided into decoding and linguistic comprehension. The theory has been used to explain and to subgroup reading disabilities. Research has also investigated if additional factors are of relevance to reading. In the present study, decoding was divided into the factors orthographic decoding and phonological decoding, while comprehension was divided into word comprehension and grammatical comprehension. The purpose was to analyze these factors and their contribution to reading ability in children in fourth grade: one group with reading difficulties (n=36) and one group with typical reading ability (n=36).

SPAX - En studie om aktieindexobligationers avkastning, risk och optimala allokering, ex post.

Syfte: Studiens syfte är att utvärdera Swedbank Markets aktieindexobligationer, SPAX, och ta fram optimala portföljen över de senaste tio åren. Den ska även fungera som ett bidrag till debatten kring aktieindexobligationer. Metod: Denna studiens huvudsakliga arbete bestod i att samla in och bearbeta den stora mängd data som krävdes för dess genomförande. Ett arbete som bedrevs genom olika databaser och över Internet. Därefter användes den teoretiska referensramen som tagits fram för att utföra beräkningar på dessa data, vars resultat sedan även sammanställdes och analyserades.

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.

New registrations in Swedish beef cattle breeding - with focus on temperament and cow weight

In today?s genetic evaluation of Swedish beef cattle, mainly traits that are directly related to productivity are measured. However, other traits, such as temperament and mature cow weight affect the economy of the farmer, as well as the welfare of the animals. This thesis evaluates possible ways of measuring new traits, with focus on temperament and mature weight of suckler cows. The goal is to examine the possible benefits of including these traits in the Swedish breeding scheme.

Mortalitet hos Newfoundland : med fokus på dilaterad kardiomyopati

Dilated cardiomyopathy (DCM) is the second most common heart disease in dogs. Since the disease is seen more frequently in certain breeds, among them Newfoundland dogs, a genetic factor is suspected. This study was partly undertaken to investigate whether there is a significant sex predilection regarding DCM. Moreover, the difference in mean age of death between male dogs and females with DCM was investigated, as well as males and females dying from DCM compared to dying from other reasons (i.e. without DCM).

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