“…Several other studies have also evaluated the effects of supplementing black cumin ( Nigella sativa L.) seeds on broilers, quails and laying hens. Although some authors failed to find any effect by supplementing Japanese quails diets with black cumin [ 49 ], others reported improved growth performance in quails [ 50 , 51 ] broiler chickens [ 52 ] and laying hens [ 53 , 54 ]. These growth-promoting effects have been attributed to the presence of a large number of pharmacologically active compounds such as thymoquinone, dithymoquinone, thymohydroquinone, nigellone, melanthin, nigilline, nigelamine, damascenone, p -cymene and pinene and a variety of essential nutrients including vitamins A, B, C, D and E, as well as minerals such as magnesium, calcium, phosphorus, potassium, iron, cobalt, zinc and manganese [ 41 , 55 ].…”