The objective of this study was to compare the performance and carcass characteristics of lambs from three genetic groups slaughtered at the same stage of maturity, reared in feedlot (confinament). Twenty-three castred male lambs were used. Seven were of the Ideal breed (I), eight were ½ Texel + ½ Ideal (F1) and eight were ¾ Texel = ¼ Ideal (F2). The average age of the lambs was three to four months. The lambs were slaughtered at the moment in wich they attained 65% of the mature weigth of the ewes in their respective genetic group, which corresponded to 25.5kg for Ideal, 30.9kg for F1 and 31.7kg for F2. No significant difference (P>.05) was observed between the three genetic groups for the following parameter: dry matter consumption (g/UTM/day and kg/100kg PV), feed conversion, number of days in confinement, coefficient of loss due to chilling, carcass yeld. The Ideal lambs presented a smaller average daily gain, live weight at slaughter (P<.05) than the cross-bred lambs (F1 and F2); however, the cross-bred lambs did not differ betwwen themselves (P>.05). The F2 lambs presented higher hot and cold carcass weights (P<.05) than the Ideal and F1 lambs; therefor the Ideal and F1 lambs did not differ between themselves (P>.05). In relation to the consumption, the F2 cross-bred lambs presented higher consumption (P<.05) than the Ideal lambs; however, the cross-bred lambs (F1 and F2) and the (Ideal and F1) cross-bred lambs, did not differ between themselves (P>.05).
carcass yield; cross-bred; feed conversion; daily weight gain
