The influence of cows’ age and the season of conception on the incidence of twin pregnancies in Polish Holstein-Friesian cattle

<ns3:p>The occurrence of twin pregnancies poses a significant challenge to the profitability of dairy cattle production. In recent decades, an increase in their frequency has been observed, with numerous studies suggesting that improved nutrition is among the contributing factors. Multiple pregnancies are associated with various adverse consequences for both cows and calves, including metabolic disorders, retained placenta, dystocia, increased calf mortality, and reduced birth weight. The objective of this study was to analyze the impact of cow age and the season of conception on the incidence of twin pregnancies in Polish Holstein-Friesian cattle. The research data, covering the period from 2016 to 2024, were obtained from barn records, cow and heifer cards, the DeLaval DelPro management program, and insemination certificates collected from a single herd where artificial insemination was implemented. Statistical analysis was conducted using the chi-square test. The results demonstrated a statistically significant association between cow age and the frequency of twin pregnancies (p = 0.0014), whereas no significant relationship was found between the season of conception and twin pregnancy occurrence (p = 0.6512). These findings may be valuable for breeders, aiding in the refinement of reproductive management strategies to mitigate the negative consequences of twin pregnancies for both cows and calves.</ns3:p>