Incidence of health disorders in dairy farming systems in western France

Abstract

Incidence of health disorders was described in 205 dairy farms in Pays de la Loire (France) in 1995/97 and compared between farming systems. Cases recorded by farmers with standard definitions were checked every month during 2 years. Incidences varied widely between herds. Median and mean values were, respectively, in cases per 100 cow-years, 40.2 and 44.1 for clinical mastitis (5.7 and 7.1 systemic mastitis), 7.6 and 10.9 for locomotor disorders, 3.3 and 5.1 for digestive disorders, and, in cases per 100 calvings, 8.1 and 8.8 for retained placenta, 5.2 and 6.6 for dystocia, 4.9 and 5.6 for milk fever, 1.9 and 5.1 for chronic metritis; somatic cell counts exceeded 200 000 cells/ml in 26.6% monthly test-days, d to first artificial insemination (AI) exceeded 90 days postpartum in 25.4% of first AI, and of total AI return rate was 50.4%. In 28% of the herds, health status was characterised by low incidences for all disorders, whereas 10% had high incidences for most disorders, 21% for several peripartum disorders or chronic metritis, 14% for retained placenta and locomotor disorders, 15% for milk fever only and 11% for mastitis only. Incidences varied widely within all farming systems. In each system, every category of herd-health status was present, and more than 20% of the farms had a low-incidence status. Little variation was associated with size of the dairy unit or dairy specialisation of the farm. Non-Holstein herds had less clinical mastitis, better reproductive performance and more dystocia than Holstein herds. Among Holstein systems, clinical mastitis were more frequent in farming systems with highest than with lowest intensification of the dairy production, whereas high somatic cell counts were less frequent. The most intensive group had the highest median incidence for nine out of 14 cow disorders. Variations were higher within than between farming systems.