Posters SURVIVAL ANALYSIS FOR LENGTH OF PRODUCTIVE LIFE OF BEEF COWS
نویسنده
چکیده
Survival analysis is applied to records for length of productive life of Angus cows, fitting several proportional hazards models. It is shown that a piece-wise Weibull model with a time-dependent stage effect can model the distinct annual culling pattern reasonably well. Analyses fitting a sire model suggest some genetic variability, with heritability estimates on the logarithmic scale ranging from 6 to 10%. Issues of data quality and the need for whole herd inventory recording are discussed.
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