Sökning: "dairy cow"

Visar resultat 1 - 5 av 45 avhandlingar innehållade orden dairy cow.

  1. 1. Sleep in dairy cows

    Författare :Emma Ternman; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Little is known about rest and sleep in dairy cows, but it has been shown in other species that the total amount of sleep, duration of sleep bouts and distribution of sleep over 24 hours differ depending on health status, age, pregnancy and lactation. Sleep recordings conducted on cows with surgically implanted electrodes have shown that they sleep four hours per 24-hour period. LÄS MER

  3. 2. Feed efficiency in dairy cows: individual cow variability in component traits

    Författare :Abdulai Guinguina; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Feed efficiency (FE) varies between cows, and this variation is linked to the variation in energy metabolism variables. Respiration chambers are needed for measuring energy metabolism variables while individual cow dry matter intake (DMI) records are necessary for measuring FE, but these are difficult to obtain due to cost and logistic constraints. LÄS MER

  4. 3. Methane production in dairy cows : individual cow variability in methane production

    Författare :Edward Hernando Cabezas Garcia; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Enteric methane (CH4) emissions vary between individual cows, and this variation is attributed to both animal and dietary factors. In addition, measurement technique of in vivo CH4 emissions from individual animals still represents a major challenge for successful emissions mitigation strategies. LÄS MER

  5. 4. Dairy cattle mating plans at herd level using genomic information

    Författare :Christian Bengtsson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Genotyping of dairy cattle can benefit farmers by increasing the accuracy of breeding values and improving mating plans at herd level. Validation studies on breeding values in this thesis revealed that for the vast majority of traits analysed in Holstein, Jersey and Nordic Red Dairy Cattle, genomically enhanced breeding values for virgin heifers were able to predict cow performance significantly more accurately than parent average breeding values. LÄS MER

  7. 5. Dry period length of dairy cows : milk composition and quality

    Författare :Ruben De Vries; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : A dry period of dairy cows is historically seen as a period during which the cow can restore its body condition and regenerate its mammary epithelium in order to be high yielding in the successive lactation. Recent work has indicated that high yielding cows generally experience a severe negative energy balance in early lactation. LÄS MER