Quantifying Dairy Breeding Goals. 2. Perceived Relative Contributions of Type Traits to Total Merit

A forced choice technique was used to obtain decisions to describe perceived differences in total merit between pairs of cows. The study consisted of 9,240 decisions by 91 respondents from three groups of dairy breeders: private dairy producers, consultants with artificial insemination organizations, and classifiers from breed associations. Decisions were used to quantify the perceived contributions to total merit from milk, fat percent, and 15 type traits. The range of values, relative to milk and traits expressed in phenotypic standard deviation units, was .19 to .64. These values were evaluated at midpoint of the scale for type traits not having an intermediate optimum. The mean of relative value for 6 udder traits was .48 and the mean for 4 body dimension traits was .26. In general, the differences in breeding goals among respondents were not significant. Effects examined were respondent's age, experience, breed familiarity, and breeder group on merit value from each trait. Several two-way interactions of effects were significant for a number of traits. Age by group interactions were most numerous.