This study was performed on six commercial dairy
farms located in Rio Grande do Sul state, southern Brazil(27300–30 South; 51300–54200West) from 2008 to 2012.
All those were grazing dairy herds with similar genetics
and management practices. Average milk production per
cow of the entire herd was approximately 7000 kg (w24 L
of milk adjusted for 305 days of lactation). All cows were
milked twice a day, and daily milk yield was recorded once
a week throughout the experiment in all herds