Sökning: "Egg laying"

Visar resultat 1 - 5 av 33 avhandlingar innehållade orden Egg laying.

  1. 1. Welfare indicators in laying hens

    Författare :Malin Alm; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : There is a growing concern regarding the welfare of laying hens worldwide and there are both ethical and economic reasons for improving their welfare. Although several different welfare indicators are used today, their ability to accurately reflect welfare status is sometimes questioned. LÄS MER

  3. 2. Erysipelothrix rhusiopathiae in laying hens

    Författare :Helena Eriksson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : The bacterium Erysipelothrix rhusiopathiae can infect a wide range of mammals (including humans) and birds. Disease outbreaks (erysipelas) have been considered unusual in chickens internationally, but outbreaks with high mortality and egg production losses have been diagnosed in Swedish laying hen flocks every year since 1998. LÄS MER

  4. 3. Parental and embryonic behaviours in precocial birds

    Författare :Irene Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pheasants; growth rate; oxygen consumption; hatch synchronization; incubation behaviour; nest predation; physical condition; Egg laying; primary sex ratio; mallards; Animal ecology; Djurekologi;

    Sammanfattning : This thesis deals with behaviours during reproduction in precocial birds, both from the perspective of the female and of the embryos. Female pheasants in good physical condition laid larger eggs and produced a higher proportion of daughters than females in poor condition. LÄS MER

  5. 4. Genomics of heterosis and egg production in White Leghorns

    Författare :Esinam Amuzu; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Crossbreeding  is  practiced  extensively  in  commercial  breeding  programs  of many  plant and animal species, in order to exploit heterosis, breed complementarity, and  to  protect  pure  line  genetic  material.  The  success  of  commercial  crossbreeding  schemes depends on identifying and using the right combination of breeds, lines or  varieties  that  produce  the  desired  crossbred  offspring. LÄS MER

  7. 5. Codling moth, Laspeyresia pomonella L. (Lepidoptera) egg-laying strategies and larval behaviour in relation to various selection factors

    Författare :Sutat Subinprasert; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER