Seventy-five ewe lambs (15 Santa Inês, 15 ½Dorper+½SI, 15 ½Ile de France+½SI, 15 ½Suffolk+½SI e 15 ½Texel+½SI) were mated to Dorper rams and evaluated during lambing and lactation. Number of lambs born/ewe, birth weight, weaning %, ewes's DMI, milk yield, milk composition, body condition score, nonesterified fatty acids and lamb performance were evaluated. Milk production was measured every 7 d, from the second to the eighth week of lactation. Ewes were separated from lambs, oxytocin (10 IU) was infused, i.v., to stimulate milk letdown, and ewes were mechanically milked. After 3 h, the procedure was repeated and milk production was recorded and a sample collected for milk composition analysis. SI ewes showed higher (P<0.05) DMI as % of BW when compared to ½DO, ½IF and ½SK. A higher milk fat, total solids and fat corrected milk was observed for ½DO than ½IF. ½TX ewes produced more kg of weaned lambs than SI (27.2 kg vs. 17.3 kg). ADG for ¼TX lambs was higher (P<0.05) than ¾DO (283 g vs.229 g).