Effects of different levels of dietary black cumin (Nigella sativa L.) and fenugreek (Trigonella foenum-graecum L.) and their combination on productive traits, selected blood constituents, microbiota and immunity of broilers

The effects of inclusion of powdered seeds of black cumin (B) (Nigella sativa L.) and fenugreek (F) (Trigonella foenum-graecum L.) on productive traits, selected blood constituents, microbiota and immunity of broilers were studied. A total of 648 day-old chicks were randomly assigned to nine treatments, with four pen replicates, each with 18 birds, including three levels of B seed powder (BSP; 0, 5 or 10 g/kg) and three levels of F seed powder (FSP; 0, 5 or 10 g/kg) in a 3 × 3 factorial arrangement. Neither powder affected feed intake. The FSP increased (p = 0.048) feed conversion ratio (FCR), but decreased daily BW gain (p = 0.02) between days 0 and 21, while BSP increased daily gain between days 22 and 42 and overall (both p = 0.005). Abdominal fat was decreased (p = 0.003) by BSP. Blood constituents were unaffected by either powder, but ileal Escherichia coli were decreased (p = 0.039) at day 42. The BSP increased a range of immunological titers, where BSP affected positively the measured variables. The interactions between BSP and FSP, specifically on broiler carcass cuts, suggested that where BSP is included at 10 g/kg, the inclusion of FSP at the same level may provide no additional benefit. Thus, while either powder could be included separately, the co-inclusion of both at 10 g/kg is not recommended.