Test-day records of purebred Tsigai (T), Improved Valachian (IV) and Lacaune (L) ewes were used to analyse the effect of environmental factors on milk fat and protein content. Overall means and standard deviations for fat and protein content were 7.77% and 5.94% for T, 7.48% and 5.82% for IV, and 6.97% and 5.62% for L. For fat content, analyses showed a highly significant (P < 0.01) effect of flock-test day and a highly significant or significant (P < 0.05) effect of the month of lambing, with the onlyexception of L. The effect of litter size was highly significant or significant in IV and L. For protein content, analyses showed a highly significant effect of flock-test day and a highly significant or significant effect of the month of lambing. The effect of litter size was highly significant in T and IV. The model explained about 50% of fat and protein variation in the breeds.