My preference is to allow yearlings to raise a youngster, I feel it not only bonds them to their nestbox but also to their new loft/compartment. If your pushed for time there's many options open to you. You can remove their hen and youngsters to your young bird loft when young are 14 days old (the hens will finish of rearing)they are on w/hood from this point. If you decide you don't want them to rear let them go down on eggs and race them to eggs for the first couple of races then on w/hood thereafter. Another option is to miss the first few races which can work in your favour if the weather should turn out naff, yearlings x w/hood x cold weather doesn't mix very well.