Sökning: "heterosis"

Visar resultat 1 - 5 av 6 uppsatser innehållade ordet heterosis.

  1. 1. Investigation of pollen limitation, inbreeding and outbreeding depression and heterosis in Euphrasia stricta var. suecica on Gotland

    Master-uppsats, Uppsala universitet/Institutionen för biologisk grundutbildning

    Författare :Emelie Nilsson; [2017]
    Nyckelord :Pollen limitation; inbreeding depression; outbreeding depression; heterosis; Euphrasia stricta var. suecica; selfing; conservation;

    Sammanfattning : Habitat fragmentation is one of the main threats to semi-natural grasslands all over Europe, causing reductions in both numbers of populations and numbers of individuals withinpopulations. Small isolated populations are particularly vulnerable to fluctuations that reducespopulation size and could lead to loss of genetic variation due to inbreeding depression, orfixation of harmful alleles due to genetic drift. LÄS MER

  3. 2. Case study: phenotypic and economic effect of crossbreeding in a Swedish red and white dairy cattle herd

    Master-uppsats, SLU/Dept. of Agricultural Research for Northern Sweden

    Författare :Victoria Ekenberg; [2017]
    Nyckelord :crossbreeding; heterosis; case study; dairy cattle; SRB; Holstein; Montbéliarde; Jersey;

    Sammanfattning : Profitable dairy production is always strived for. In recent years, dairy production in developed countries struggle with genetic problems like increasing inbreeding, reduced fertility and at the same time increasing market demands for competitiveness. LÄS MER

  4. 3. Estimation of heterosis and performance of crossbred Swedish dairy cows

    Master-uppsats, SLU/Dept. of Animal Breeding and Genetics

    Författare :Rebecka Jönsson; [2015]
    Nyckelord :breed group effect; heterosis; crossbreeding; dairy cows; functional traits; production traits;

    Sammanfattning : The heterosis effect and breed group effect of crossbreds between Swedish Holstein (SH) and Swedish Red (SRB) was estimated in this study. Observations on cows born between 1990 and 2012 were used to estimate the heterosis effect and breed group effect for several traits included in the Nordic breeding goals: production, fertility, udder health, calving performance, survival and other diseases. LÄS MER

  5. 4. Variation i fruktsamhet hos semingaltar

    Magister-uppsats, SLU/Dept. of Animal Breeding and Genetics

    Författare :Camilla Knutson; [2011]
    Nyckelord :galt; artificiell insemination; fruktsamhet; spermakvalitet; omlöpsförekomst;

    Sammanfattning : Artificial insemination (AI) has had a great influence on the development of pig production and is today widely practiced (Gerrit et al., 2005). With AI, genetic progress can at a short period of time be spread worldwide compared with using natural service and the best boars can be intensively used. LÄS MER

  7. 5. Crossbreeding in dairy cattle

    Kandidat-uppsats, SLU/Dept. of Animal Breeding and Genetics

    Författare :Angelica Lundgren; [2011]
    Nyckelord :crossbreeding ; breeding strategy; heterosis; dairy cattle; korsningsavel; avelsstrategi; heterosis; mjölkkreatur;

    Sammanfattning : The aim of this literature review is to give an overview of the differences between pure- and crossbreeding systems. Crossbreeding is a mating system with individuals of different lines or breeds. It is one of several breeding strategies in dairy production used to increase the economic profit. LÄS MER