Tuberculoid nodular thelitis in a dairy goat flock.

An unusual outbreak of teat/udder skin lesions occurred in a dairy goat flock in France. Lesions first appeared as circular, indurated, erythematous areas of skin and progressed to form dark raised haemorrhagic crusts and ulcerative plaques. Histopathological examination revealed marked granulomatous dermatitis with multifocal ulceration. The granulomatous inflammation, with frequent Langhans type multinucleated cells and central caseous necrosis, was indicative of mycobacterial infection. The presence of non-cultivable mycobacteria was confirmed by sequencing PCR products from DNA extracted directly from the lesions and sequences matched a novel mycobacterial pathogen closely related to M. leprae and M. lepromatosis and previously identified in cattle thelitis. The association of nodular gross lesions and tuberculoid granulomas on the teat and lower udder, and the presence of mycobacteria DNA support a diagnosis of tuberculoid nodular thelitis in goats due to mycobacterial infection.

Does milk yield reflect the level of welfare in dairy herds?

Under the assumption that milk yield may be reduced in herds with impaired welfare, the present study aimed at investigating whether milk yield could be used as a reliable indicator of welfare. In 125 commercial French dairy herds, the association between the welfare of the herd (evaluated using the Welfare Quality assessment protocol) and cow milk yield was investigated using linear mixed models. Positive associations were identified between milk yield and low aggressions between cows and good emotional state of the herd but there was a negative association with good health assessed through the occurrence of diseases and injuries. These opposite associations resulted in no association with the overall welfare of the herd. Milk yield should not therefore be used as an indicator of overall welfare.