Associations between hygiene scores and udder health parameters in organic dairy herds

One important goat of organic farming is the promotion of animal health and the reduction of antibiotic treatments. 22 organic dairy herds participated in a project with the aim to phase out antibiotic treatments. Under these conditions somatic cell count (SCC) and records of treated cases of mastitis may be insufficient to document udder health and animal welfare. The aim of our study was to assess and characterise udder health by using systematic clinical examinations. The udders of 50 cows per farm were clinically examined during milking at the beginning of the project period. The hygiene of body and udder was scored. The data was analysed using Principal component analysis and a general Linear model. The prevalence of cows with knotty tissue ranged from 0-0.46, the prevalence of cows with nodes in the udder from 0-0.17 and the prevalence of cows with a dry quarter from 0-0.18. Danish Holsteins had a higher number of udder treatments per 100 cow years than Jerseys. Principal component analysis extracted two components: component 1 was characterized by udder and body hygiene scores, number of antibiotic treatments and Danish Holsteins, whereas component 2 was characterized by nodes in the udder, knotty tissue and blind quarters. Farms loading high on component 2 had a higher calculated bulk milk SCC. Nodes, knotty tissue and blind quarters were not associated with the number of udder treatments. This indicates that a tower treatment frequency did not lead to a higher proportion of cows with chronic mastitis. The different management practices in the farms will be further discussed in the presentation. Systematic clinical udder examinations were useful tools to monitor udder health.