Effects of Nigella sativa Seed as a Natural Alternative to Antibiotic Growth Promoters on Performance, Antioxidant Status, and Meat Quality of Chickens

In the current study, Nigella sativa (NS) seed powder was evaluated as a potential natural alternative to antibiotic growth promoters in the diet of broilers to check its impact on the growth performance, antioxidant status, carcass characteristics, and meat quality of broilers. For this purpose, a total of 400 one-day-old male broiler chicks (Ross-308; Gallus gallus domesticus) were divided into five dietary treatments: negative control, 50 mg lincomycin/kg feed, 1% NS, 2% NS, and 3% NS (NS added on top of the basal diet at 10, 20, and 30 g/kg). Each treatment had 10 replicates and each replicate had 8 birds, and the total duration of the experiment was 35 days. Results showed that broilers fed 1% NS exhibited the highest overall body weight gain (p < 0.001), and NS supplementation improved the feed conversion ratio (FCR) during the finisher phase and in the overall phase (0–35 d) (p < 0.001), with the best overall FCR at 1% NS, whereas mortality did not differ among treatments (p > 0.05). Total tract nutrient digestibility and ileal crude protein and dry matter digestibility were improved by 1% and 2% NS supplementation (p < 0.05). NS supplementation reduced thiobarbituric acid (TBA) values and increased glutathione peroxidase activity in both thigh and breast meat, and increased superoxide dismutase activity in breast meat at all NS levels and in thigh meat at 2% and 3% NS (p < 0.05). Dressing percentage, breast and thigh meat yield, and relative organ weights did not differ among treatments (p > 0.05). NS increased water-holding capacity and reduced shear force (at 2% and 3% NS) and drip loss (at 3% NS) (p < 0.05), whereas meat pH at 1% and 2% NS was lower than in the AGP group but did not differ from the control. In conclusion, dietary inclusion of NS, particularly at 1–2%, enhanced body weight gain, feed conversion ratio, nutrient digestibility, antioxidant status, and meat quality of broiler chickens, although carcass yield was not significantly affected.