Effects of Dietary Black Cumin Seed (Nigella sativa L.) Meal on Performance, Gut Health, and Meat Quality of Japanese Quail

This study investigated the effects of dietary black cumin seed meal (BCSM) supplementation on growth performance, carcass traits, intestinal histomorphology, cecal microbiota, meat quality, and breast meat malondialdehyde (MDA) levels in Japanese quail. A total of 200 one-week-old quail were randomly allocated to four dietary treatments containing 0, 5, 10, or 20 g/kg BCSM for a 35-day experimental period, with five replicates per treatment. Dietary BCSM supplementation did not significantly affect body weight, body weight gain, feed intake, or conversion ratio (<i>p</i> > 0.05). However, carcass weight was significantly increased in birds fed 20 g/kg BCSM (<i>p</i> < 0.05), while carcass yield and relative internal organ weight remained unchanged. Intestinal histomorphology was markedly influenced by dietary treatments (<i>p</i> < 0.05), with improved villus height and villus height-to-crypt depth ratio in the jejunum and ileum of BCSM-fed birds. In addition, cecal microbiota analysis revealed a dose-dependent increase in <i>Lactobacillus</i> spp. (<i>p</i> < 0.05), whereas <i>Escherichia coli</i> counts were numerically reduced but not statistically affected (<i>p</i> > 0.05). Meat quality evaluation showed that BCSM supplementation significantly increased breast meat lightness (L*) and water-holding capacity and reduced post-slaughter pH values (<i>p</i> < 0.05). Lipid oxidation, as assessed by malondialdehyde (MDA) concentrations, was observed to be significantly lower in breast meat during refrigerated storage, suggesting a potential improvement in oxidative stability and a possible contribution to extended shelf life (<i>p</i> < 0.05). In conclusion, dietary inclusion of black cumin seed meal, particularly at 20 g/kg, positively modulated intestinal health, cecal microbiota composition, and meat oxidative stability without compromising growth performance. Owing to its high nutritional value and rich bioactive compound profile, BCSM can be considered a functional and sustainable feed ingredient for quail nutrition.