Reasons and Risk Factors for the Incidences of Perinatal Calf Mortality and Twin Births in Locally-Born Holstein Dairy Cows Under Hot Environmental Conditions

Perinatal calf mortality (PCM) and multiple pregnancies (twins) present significant challenges in dairy cattle breeding, impacting both economic viability and reproductive performance. This study examined risk factors for stillbirths and twin births in a dairy farm located in Algeria’s Northern Sahara, analyzing 1047 full-term calving records of locally-born purebred Holstein cows. Binary logistic regression models were employed to identify factors influencing PCM and twin births. During the study period (1995 – 2017), 7.07 % of calvings resulted in stillbirths, and 3.15 % resulted in twins. PCM was strongly associated (p = 0.0001) with severe dystocia, calf gender, and retained placenta, as well as gestation length (p = 0.023), dam parity (p = 0.019), and temperature-humidity index (THI) at breeding (p = 0.025). The likelihood of twin births was higher in multiparous cows and significantly associated (p = 0.034) with heat stress conditions at parturition (THI-P). These findings highlight the need for targeted management strategies during the peripartum period to mitigate reproductive disorders and reduce financial losses in dairy herds.