Using Nigella sativa seed meal as a substitute for soybean meal in broiler diets

The proximate chemical composition, mineral, fatty acid, and amino acid profiles of Nigella seed meal (NSM) was determined. In addition, apparent (AAAU) and true (TAAU) amino acid utilization, and apparent (AMET) and true (TMET) metabolisability were determined using a force-feeding bioassay with two groups of eight cockerels each at 20 weeks old. Furthermore, a protein efficiency bioassay was conducted with 160 Ross-308 unsexed broilers aged between 22 and 42 days. These broilers were randomly assigned to two treatments, each with eight replicates of 10 broilers. The broilers were fed two diets in which soybean meal 44% CP (SBM) and NSM were the main protein sources. NSM contains approximately 35% crude protein, 10% ether extract, and significant amounts of minerals, fatty acids, and amino acids. AAAU and TAAU were 82.33% and 89.17%, whereas AMET and TMET were 2998 and 3780 kcal/kg, respectively. The protein efficiency bioassay clarified the possibility of using NSM instead of SBM in broilers diets aged 22-42 days of age. NSM is a rich source of nutrients that can be tested in further studies to estimate its capability as a source of protein in broilers diets during the whole period of growth (1-42 d of age). Moreover, testing higher levels of NSM in broilers diets is of the utmost importance in future studies.