Curvas de lacta？？o de vacas holandesas do Estado do Paraná, Brasil

a data set from the dairy herd analysis system in the state of parana, brazil (parlpr - apcbrh), containing 27029 lactation records from 422 herds, was used to plot lactation curves. lactation curves were plotted according to three parity groups and six levels of production. production at peak increases with increases in herd production level and with increases in lactation number. daily decline increases with increases in herd production level, in the case of second or greater lactation; for first lactation animals, no trend was identified for this characteristic. the curves, peak and persistency values obtained are to be used as management tools on dairy farms in the state of parana.