Some recents studies (Manso et al., 1993; Iason and Mantecon, 1992) have indicate changes in dimensions of digestive tract in response to pattern of nutrient supply during lamb growth. The extent of this changes could be influenced with the age or stage of maturity at wich the different feeding strategies are applied (O 'Donovan, 1984; Ryan, 1990) and could affect the digestive diet utilization during lamb growth. Knowledge of variation of digestive diet utilization can help in developing strategies to optimize the use of feedstuff by animals.
The objetive of this work was to study the effect of level of intake during milk fed period and undegradable protein content in the diet during post-weaning period on the apparent digestibility of postweaning diet in Churra lambs two weeks after weaning and at 20 Kg live weight (LW).