Data from a growth selection experiment, carried out in Brazil, was analyzed in order to evaluate the effects of the selection for body weight on size and reproductive traits of the cows. The experiment started in 1978, with 3 lines of Nelore cattle, selection (NeS), traditional (NeT), both selected for higher yearling weight, and control (NeC), selected for mean yearling weight. Means for weight and height at the beginning of the breeding season, days to calving and calving success of cows pertaining to 3^td to 4^th generations of selection, were contrasted between the selected and control lines. Cows from NeS and NeT were 15% heavier than those cows from NeC. For the reproduction traits, no significant difference was detected between the selected lines and the control. These results show that successful selection for body weight had not negative effects on the reproductive performance.

7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France