Data on milk yield in 305 days of lactation and lactation period of 217 lactations of 104 Flemish and Holstein cows from the Experimental Station of Lages, Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina (EPAGRI) were analysed. Means, standard errors and coefficients of variation from milk yield in 305 days of lactation and lactation period were 4.179.48 ± 89.65kg and 22.33% and. 305.17 ± 4.91 days and 15.16%, respectively. Performances of the Flemish cows were poorer than the Holstein cows in 24.5% for milk yield ( 4763 vs. 3959kg) and in 8% for lactation period (317.9 vs. 292.4 days). Calving season affected only the lactation period. Lactations started in summer were longer than those started in spring. Calving age showed a quadratic effect on milk yield. The age of the top production were 69 and 96 months for Holstein and Flemish cows. Year of parturition did not affect milk yield and lactation period.
dairy caule; lactation period; milk production; flemish and holstein breeds
