Resumen de GM 15. The Longevity in Carora Breed: effects of management types and years
M. G. Giuliani, Rita Rizzi, Martin Hahn, Franco Cerruti
Data were obtained from 5935 purebred Carora cows born from 1958 to 1995. Survival and culling probabilities for five-month time intervals were determined by using the life table method. Differences for survival among three different types of management and four period (1961-1968, 1969-1976, 1977-1984, 1985-1992) were evaluated by the Mantel-Haesznel test. Survival differences are found among the management types, due likely to more intensive selection in herds with higher yield. Hazard function allow to determine higher culling rates after first calving. Survival at 96 months is increasing in herds with higher management level.
