Sökning: "animal breeding"

Visar resultat 1 - 5 av 108 avhandlingar innehållade orden animal breeding.

  1. 1. Genetic Heteroscedasticity for Domestic Animal Traits

    Författare :Majbritt Felleki; Erling Strandberg; Lars Rönnegård; Ole Fredslund Christensen; Högskolan Dalarna; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Quantitative genetics; genetic heteroscedasticity of residuals; genetic heterogeneity of environmental variation; genetic heterogeneity of residual variance; double hierarchical generalized linear models; teat count in pigs; litter size in pigs; milk yield in cows; somatic cell count in cows; Complex Systems – Microdata Analysis; Komplexa system - mikrodataanalys;

    Sammanfattning : Animal traits differ not only in mean, but also in variation around the mean. For instance, one sire’s daughter group may be very homogeneous, while another sire’s daughters are much more heterogeneous in performance. The difference in residual variance can partially be explained by genetic differences. LÄS MER

  3. 2. Selection, Maternal Effects and Inbreeding in Reindeer Husbandry

    Författare :Lars Rönnegård; Högskolan Dalarna; []
    Nyckelord :breeding programme; communal grazing; randombred populations; Rangifer tarandus tarandus; semidomestic reindeer; gene flow; reindeer; animal breeding; gene flow; random mating; breeding methods; genetic inheritance; population structure; extensive husbandry; sweden;

    Sammanfattning : In extensive grazing systems where several owners’ flocks are allowed to mix, selection strategies will also interact, due to gene flow between flocks. The aim of the thesis was to analyse breeding schemes in terms of genetic gain and rate of inbreeding (?F), given the complexity of ownership and interaction of selection strategies within a mixing reindeer population. LÄS MER

  4. 3. Breeding for durable riding horses using competition statistics

    Författare :Åsa Braam; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : The breeding objectives for Swedish Warmblood horses are aiming for producing horses that have a good conformation and are internationally competitive in dressage and show jumping. It also states that the horses should be durable. LÄS MER

  5. 4. International breeding programs to improve health in pedigree dogs

    Författare :Shizhi Wang; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Implementation of breeding programs in order to reduce incidence of inherited disorders and their impact on welfare should be a priority for dog breeders and breeding organizations. In that respect, exchange of breeding animals between countries constitutes a critical point to be taken into account. LÄS MER

  7. 5. Progesterone profiles, oestrus expression and pregnancy in dairy cows

    Författare :Sofia Nyman; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : The cow’s ability to reproduce is essential for milk production. Traditionally genetic evaluations for fertility have been based on measures on insemination- and calving dates, which in general are highly influenced by on-farm decisions. Unfortunately, the low heritability of classical fertility traits makes the genetic improvement slow. LÄS MER