The earlier it is cut, the better energy.
More energy is found in the leaf than in the stem.
Rain and high moisture silages also will reduce the energy level. Amino acids from protein is needed for tissue formation, wool growth, and body maintainence. Quantity is more important than quality except late in pregnancy and lactation. Six weeks before lambing and for the 6 wks. during lactation., protein supplementation should be high in the form of fish meal or heat treated soybean meal. Good sources are hay silage, high moisture corn, and corn silage.