Peter Burfening

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Results are summarized of necropsy findings from 798 calves lost from birth to weaning over a 15-yr period. Autopsies determined cause of death and ascertained anatomical normalcy of the skeletal, musculature and organ systems and functinal status of the lungs. Of the 798 calves, 77.7% were anatomically normal and 22.3% were abnormal (P < 0.01) and 75.0% of(More)
Birth weights (BW) and weaning weights (WW) of 4,423 non-creep-fed Hereford calves were used to estimate direct and maternal sources of variation and maternal phenotypic effects (fm). Seventeen different (co)variances among relatives were estimated through Henderson's Method III and restricted estimated maximum likelihood procedures. Direct and maternal(More)
Sixty-two, 2-yr-old heifers and 65 cows, 4 to 7 yr old, were assigned randomly at 60 d before the median predicted calving date to a factorially designed study. Main effects were: age of dam (heifer or cow), moderate (M) or high (H) precalving feed level (110 or 135% of National Research Council recommendation) and short (S) or prolonged (P) duration of(More)
Standard linear adjustment of weaning weight to a constant age has been shown to introduce bias in the adjusted weight due to nonlinear growth from birth to weaning of beef calves. Ten years of field records from the five strains of Beefbooster Cattle Alberta Ltd. seed stock herds were used to investigate the use of correction factors to adjust standard(More)
Factors affecting survival of young from birth to weaning (7 mo) in alpacas (Lama pacos) were evaluated in data collected at the Estacion Experimental de Camelidos Sudamericanos La Raya in the Altiplano region of Peru. Age of dam effects on survival rate were curvilinear; survival rate increased from approximately 78% for offspring of 3-yr-old dams to about(More)
Field records from the American Simmental Association were used to estimate genetic parameters for direct and maternal effects of traits associated with dystocia. Estimates of the additive genetic variances of direct and maternal effects and of the additive genetic covariances of direct and maternal effects were calculated by equating the sire variance(More)
Data from 13,296 calvings collected over a 15-yr period indicated 893 calves died from birth to weaning for an average loss of 6.7%. Calves lost from birth through Day 3 postcalving accounted for a 4.6% loss with an additional 2.1% loss from Day 4 through weaning. Calf deaths from primiparous 2- and 3-yr-old dams accounted for 41.0% of total mortality.(More)
Research has been conducted as part of the Small Ruminant Collaborative Research Support Program (SR-CRSP) on evaluation of genetic resources and methods of effecting genetic improvement of small ruminants in the participating countries. In Kenya, the focus has been on development of a dual-purpose goat for milk and meat production in farming areas,(More)