Combinations of Linear Type Traits Affecting the Longevity in Hungarian Holstein-Friesian Cows

SIMPLE SUMMARY: The selection for high-level milk production shortened the productive life of cows. In Hungary, the average number of lactations is only ca. 2.1. At the same time, the longevity, health status, milk production and reproduction were affected by the linear type traits, confirmed by several research studies. These studies, however, looked at the association of the linear type traits with longevity, using only one trait at a time. To take into account the connections between linear type traits, their combinations based on statistical analyses were considered. Identification of the risk ratio of various trait combinations could support corrective mating and bull selection. ABSTRACT: Several research studies confirm the association of the linear type traits with longevity, but only with one trait at a time. The aim of our study was to analyse the influence of combinations for linear type traits on longevity in the Hungarian Holstein-Friesian cows. Data were provided by four herds; the filtered dataset consisted of 17,717 cows. From the 14 available linear type traits, the most important combinations were identified based on principal components and cluster analysis. From the six identified combinations, only three (chest width-body depth, fore udder attachment-udder depth, angularity-rear udder height) proved to have a significant effect on longevity. A wide chest and deep body caused a high-risk ratio of culling. The lowest risk ratio was observed with cows having intermediate chest width and intermediate body depth. Very angular cows having low rear udder height were at the highest risk of culling. The lowest culling risk was found in cows with a lack of angularity and high rear udder height. Weak and loose fore udder along with deep udder had increased culling risk. Strong and tight fore udder subclasses were the most favourable as their risk ratios decreased towards the shallowing of udder depth.