STUDY ON THE AGE AT FIRST CALVING AND THE LONGEVITY OF BEEF COWS

摘要

The age at fi rst calving, the life span and the longevity of cows have great importance in cattle husbandry, especially in beef cow husbandry, because the cost of raising weaned calves depends largely on how early cows calve and how long they remain in production. If cows are productive extendedly and raise more progeny, specifi c costs of raising per calf decrease proportionally. Consideration of life span and, specifi cally, longevity plays an important role in practical breeding. The present work summarizes the results of the studie conducted in this fi eld. A database of altogether 2115 cows belonging to fi ve breeds (Hungarian Grey, Hereford, Aberdeen Angus, Limousin and Charolais) and two crossbred genotypes (Simmental x Hereford F1, Simmental x Limousin F1) born between 1977-1992 was evaluated. Age at fi rst calving (AFC), age at culling (ACU), moreover longevity (LONG) were studied. Ms Excel and SPSS for Windows 11.0 were used for statistical analyses. The mean values of AFC, ACU and LONG obtained were 2.71, 9.47 and 6.77 year, respectively. Breed/genotypes and birth year had signifi cant infl uence (P<0,01) on each evaluated trait, whereas birth month statistically affected only the AFC.