The effect of experimentally induced subclinical mastitis on milk yield of ewes and on the growth of lambs.

In each of two experiments, subclinical mastitis was induced by inoculating both mammary glands of Welsh-Mountain and Dorset-Horn ewes with a coagulase-negative staphylococcus; groups of control ewes were also included. After inoculation, the somatic cell counts of milk of the inoculated ewes increased (P less than 0.01) and the milk yield decreased (P less than 0.01). The lambs of the inoculated ewes had a poorer growth than lambs of the control ewes (P less than 0.01).