Reproductive parameters of dairy herds on different systems in west and southwest regions of Paraná state

The reproductive efficiency in dairy cattle is influenced by several factors. Through many challenges, sometimes the cow just does not perform the genetic potential as expected. Data analyzed was provided by BM intermediate in the CB (234.7 ± 5 and 272.5 ± 7 days); and smaller in the NC (189.3 ± 10.3 and 206.1 ± 9.9 days) in months average ≤25°C or ≥25°C, respectively. The temperature of ≤25°C (161 ± 14.1 days) or ≥25°C (163.5 ± 12.4 days) (P = 0.5541) had no effect on DO, however it was higher (P < 0.0001) in the FS (223.1 ± 37.1 days), followed by CB (201.63 ± 11 days) and NC (149 ± 13.04 days). Increased SCC was associated with increased embryonic death in the herds. Temperature and management practices in each system had a detrimental effect on the reproductive efficiency.