Full‐fat sunflower seed as a protein source for broiler chicks

The protein quality of hulled full-fat sunflower seed (HFFSS) was evaluated and compared to that of soyabean meal in two experiments with broiler chicks. In the first experiment, PER and NPR indexes were determined. The results showed that, when fed as the sole source of dietary protein (90 g crude protein kg−1 diet), the performance as well as PER and NPR values of chicks fed HFFSS were much poorer than those of chicks fed soyabean meal. The protein quality of HFFSS was improved greatly by lysine supplementation. The PER and NPR values for HFFSS supplemented with 0.2 and 0.4% of L-lysine equalled and even became superior to those estimated for soyabean. In the second experiment, apparent and true ileal digestibilities of nitrogen and amino acids were calculated. The apparent but not the true digestibility of the mean of amino acids was significantly lower (P < 0.01) in HFFSS than in soyabean meal (0.838 vs 0.902 and 0.932 vs 0.957, respectively). The results also showed that lysine from HFFSS was less digestible than that from soyabean meal, the apparent as well as the true digestibility values being lower in the former. © 1999 Society of Chemical Industry