ABSTRACT. The objective of this study was to evaluate the influence of sire breed (Polwarth=P, Poll Dorset=PD and East Friesian=EF) on growth, carcass and meat quality traits of lambs born to wool type ewes. A flock of multiparous Polwarth ewes was mated with connected P, EF and PD rams during three consecutive years. PD cross lambs had higher weaning, slaughtering and carcass weight and growth from birth to weaning and from weaning to slaughtering compared to the other biotypes evaluated. They also presented a higher subcutaneous fat depth at the GR point and weight of valuables cuts (Leg and Rack) but these differences disappear when the comparisons are done at constant carcass weight. PD cross lambs also presented a higher proportion of superior carcass (S) according to INAC system. EF cross lambs presented a lower subcutaneous fat depth at the GR point independently of the carcass weight that is a particular genetic characteristic of this breed. The lambs carcasses produced in this experiment achieved most quality parameters for our international markets with the exception of the subcutaneous fat depth which is under the market requirements. Some alternatives to increase the GR are presented and discussed.
