Effects of dystocia, parity and season on stillbirth in Holstein cows

摘要

One hundred eighty two primi- and multiparous artificially inseminatedHolstein cows unable to deliver by 2h from the beginning of the 2 nd stage of labor wereassumed to have dystocia and assisted for delivery of fetus. Results suggest that dystocia dueto fetal limb malposture, malposition, twin birth, or uterine torsion induced greater calfmortality up to 24h after birth than deviation of fetal head, fetopelvic disproportion oruterine inertia (P ≤ 0.05). There was no significant effect of parity of the dam on incidence ofstillbirth (P > 0.05). Less stillbirths were found during summer compared with other seasons(P ≤ 0.05).