In beef cattle and in sheep, selection for growth has led to higher birth weights and increasing risk of birth problems. Higher growth rates can also be expected to increase the mature size of breeding females. This may result in lower reproductive rates if larger animals are unable to meet their nutritional requirements because of limitations in the quantity or quality of the available forage. These undesired effects can be avoided, or at least reduced, by increasing the weight of functional traits within selection indices. This supposes that there traits can be directly measured. Recording of functional traits often remains an important bottleneck hindering their inclusion in breeding schemes. Thir is illustrated by the example of efficiency ofeed utilization. Recording feed intake in a large number of animals is currently impossible –preventing efficient selection for thir trait.