UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

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    ROLE OF MATERNAL AND CYTOPLASMIC EFFECTS IN EARLY CALF GROWTH IN A CLOSED BREEDING NUCLEUS ANGUS HERD
    (2011) Carrillo, José Adrián; Siewerdt, Frank; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Maternal and cytoplasmic inheritance was investigated in a closed Angus herd. Observed traits were birth weight, weaning weight, adjusted body weight, average daily gain, hock length and scrotal circumference. Each animal in the herd was traced to one of 18 female founders. Data was analyzed with a model including contemporary group, gender and the random effects of animal, maternal, permanent environment, and cytoplasmic line. Ratios of cytoplasmic to phenotypic variances ranged from 0.000 ± 0.002 to 0.005 ± 0.006. Genetic maternal variances had ratios ranging from 0.044 ± 0.046 to 0.156 ± 0.029. Desired genetic gains indexes were computed for all traits. Inclusion of the cytoplasmic information in the index resulted in small reductions in genetic gains in direct and maternal values that can be compensated for a corresponding increase in cytoplasmic breeding value. Selection for cytoplasmic effects will lead to increased inbreeding unless new variation is created by mutations.