Body composition changes in animals undergoing compensatory growth and these response vary with the age or stage of maturity at which the restriction is applied and with the undegradable protein in the diet during post-restriction period (O'Donovan, 1984; Ryan, 1990).

This experiment was conducted to determine the effect of level of intake during milk-fed period and the energy/protein relationship during post-weaning period on changes in carcass, non-carcass and empty body weigth (EBW) components in lambs slaughtered at 20 Kg live weigth (LW).

A total of 16 lambs of Churra breed were used in a comparative slaughter experiment to determinate the effect of level of intake during milk-fed period (4 weeks) and the protein supplement in the diet during post-weaning period on chemical body composition at 20 Kg LW

The lambs were assigned to a 2×2×4 factorial design, defined by 2 levels of milk intake (High: 1.5 MJ GE/Kg LW°75/day and Low: 0.9 MJ GE/kg LW°75/day) during milk-fed period, 2 post-weaning concentrate supplements (HP: barley grain plus 200g/kg fish meal and LP: barley) and 4 lambs per treatment.

All lambs were individually penned. During post-weaning period low quality hay and concentrate were independently offered ad libitum. Intake and LW were recorded daily and three times a week respectively. At slaughter (20Kg LW), EBW was estimated and carcass and non-carcass chemical composition (water, fat, ash and protein) and energy content was measured.