Evaluation of pelt traits in Karakul sheep applying linear and threshold models
A total of 967 animal records, of subjective trait scores, obtained between 1989 and 1990, from the control flock at the Karakul Research Station near Upington were used to evaluate 20 pelt traits in Karakul sheep, applying linear and threshold models. It seemed that categorical traits with an extended number of categories are almost continuous rather than discrete. A threshold model therefore holds no advantage over the use of a linear model. However, if the shape of the distribution is not normal, a threshold model may be preferred.