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.

The study aimed to investigate the effect of the combination of year and season of breeding period, egg weight, the annual hatching order of chicks and the hatchability of eggs on the relative risk of total loss for chicks during their 48-week life period. The examination was conducted on one of the largest farms in Hungary working with sixty breeding birds, kept in trios (one male and two females). The research covered the growing information of 1606 chicks hatched in 2019, 2020 and 2021. The highest relative risk of total loss was revealed in autumn 2020 and 2021. In comparison with the reference group (2021 summer), the relative risk of total loss was significantly lower in summer 2019 (p < 0.05) and spring 2020 (p = 0.0049) 2020 (p = 0.0000) and 2021 (p = 0.0348) spring. Both between years and between seasons the tendency of relative risk was the same. The relative risk of total loss increased until the end of the third quart of the incubation period, then remained unchanged. Chicks from groups having weak hatchability (≤50%) had the highest relative risk (p < 0.05).