Applications in survival analysis

Survival or failure time traits such as herd life and days open are both im portant economically and pose a number of challenges to an analysis based o n linear mixed models. The main features of a survival trait are that it is the time until some event occurs, and some of the observations are censore d. Survival models and the associated estimation procedures provide a flexi ble means of modeling survival traits. In this paper I will discuss the app lication of survival analysis based on the Weibull distribution. The compon ents that make up a survival model will be presented along with their inter pretation. Issues related to the model construction and estimation will be presented. (C)1999 American Society of Animal Science and American Dairy Sc ience Association. All rights reserved.