Article Details: Received: 2020-10-23 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.114-117 The objective of this study was to analyse eight milk yield and longevity traits in dependence on feeding (grazing) system. Data of purebred Slovak Spotted dairy cows (35,812 heads) culled in the period between 2006 and 2019 were evaluated. Only herds those feeding (grazing) system was known were taken into account. Dairy cows were assigned to four groups: (1) heifers not grazed, cows not grazed (17,628 heads), (2) heifers grazed, cows not grazed (13,056 heads), (3) heifers not grazed, cows grazed (156 heads) and (4) heifers grazed, cows grazed (4,972 heads). The highest average 305-day milk yield (6,139.22 kg) and lifetime milk yield (18,606.78 kg) were found in animals of group (1). Contrariwise, longevity traits were found more favourable in animals of group (4). Their productive life was by 102.78 days longer and average parity was by 0.14 higher in comparison to group (1). The differences between groups were found significant. Keywords: milk yield, longevity, grazing, heifers, cows, Slovak Spotted cattle References Bujko, J. et al. (2020). Changes in production and reproduction traits in population of the Slovak spotted cattle. Acta fytotechnica et zootechnica, 23(3), 161–166, https://doi.org/10.15414/afz.2020.23.03.161-166. Canji, V. et al. (2008). Effect of conformation traits on longevity of cows of Slovak simmental breed . Slovak Journal of Animal Science, 41(2), 83–90. Fuerst–Waltl, B. et al. (2019). Mountain pasturing of rearing stock reduces the culling rist as dairy cows. Animal , 13(1), 209–212, doi: 10.1017/S1751731118001465. Krogmeier, D. et al. (2015). The effect of alpine pasturing of heifers on the longevity and on different yield traits of cows in Simmental and Brown Swiss cattle. Zuchtungskunde, 87(2), 107–119. Petrovic, M. et al. (2009). The effect of systematic factors on milk yield in Simmental cows over complete lactations. Biotechnology in Animal Husbandry , 25(1-2), 61–71, DOI: 10.2298/BAH0902061P . Ludovic-Toma, C. et al. (2017). Comparative study on production, reproduction and functional traits between Fleckvieh and Braunvieh cattle. Asian – Australasian Journal of Animal Sciences , 30(5), 666-671, doi: 10.5713/ajas.16.0588 . SAS Institute Inc.: SAS/STAT ® 9.2User’s Guide, Second Edition , Cary, NC USA, 2009. Strapak, P. et al. (2008). Effect of selected factors on the lenght of productive life of cows. S lovak Journal of Animal Science , 41(2), 77–82. Strapak, P. et al. (2010). Relation of the length of productive life and the body conformation traits in Slovak Simmental breed. Archives Animal Breeding , 53, 393–402. https://doi.org/10.5194/aab-53-393-2010