The aim of this study was to investigate calf losses less then 1 year old in Slovenian Simmental cows and to identify the main factors contributing to increased calf mortality. We analysed data from 1,256,937 calves born between January 1, 2005 and December 31, 2020. This data comes from the Central Cattle Register, which records all information on cattle in Slovenia, including details of births, abortions and movements. In the first year of life, 9.35 % of calves died, including those lost to abortions and stillbirths. More than half (51.31 %) of these calves died before, during or shortly after calving. The proportion of calves that died increased from 8.15 % in 2005 to 9.60 % in 2020. Male calves had a higher mortality rate than female calves. Calves born as twins, triplets or more were two to five times more likely to die in their first year of life than single newborn calf. The highest calf losses were observed in primiparous cows, specifically in dams younger than 24 months. The highest mortality rate was observed in calves born in winter (9.94 %) and the lowest in calves born in spring (8.85 %).
|