EFFECT OF INDIVIDUAL AND HERD FACTORS ON BOVINE REPRODUCTION PERFORMANCE

Through a wide review of the litterature (330 references), the authors have tried to describe the determinant or predisposing effects of fac tors usually involved in the reproduction problems in beef or dairy ca ttle. These factors have been qualified as individual or herd factors. The first ones involve the animal itself like age, genetic, milk prod uction level, dystocia, twinning, perinatal mortality, placental reten tion, milk fever, uterine involution, metritis, post-partum ovarian ac tivity. The second ones concern the environnement of the animal i.e. f irst insemination policy, oestrus detection, insemination time and tec hnic, nutrition, season, stabulation, herd size or management capacity of the farmer. The authors conclude to the multifactorial etiology of the reproduction pathologies. It also appears necessary to develop da ta collection systems like herd health management programs. Such syste ms should be able to offer to the practitionner the opportunity to be involved more efficiently in the economic health of the herd using epi demiological tools to study the different implied factors.