The effect of adding saffron petal extract and biochar to diet on the performance, blood parameters and microbial population of the digestive system of Japanese quails

Background: There are reports regarding the effectiveness of using biochar in animal feed. Biochar can significantly improve animal health by absorbing toxins, stabilizing intestinal pH levels and enhancing beneficial microorganisms. It specifically targets the digestive system where it acts as a natural detoxifier and as an adsorbent for the removal of heavy metal ions including cadmium, copper, lead and zinc. In addition to having positive effects in poultry nutrition, biochar can also reduce feed costs. Aim: This experiment was conducted to investigate the effect of adding saffron petal extract and biochar to diet on performance, blood parameters, and microbial population of the digestive system of Japanese quails. Methods: A total of 500 one-day-old Japanese quails were used in a completely randomized design with 5 treatments, and 5 repetitions. And in each repetition, 20 quails were tested for 45 days. The treatments included: 1) diet without additives (control), 2) basic diet +1% probiotics, 3) basic diet in addition to 1% pistachio husk biochar, 4) basic diet + 500 mg/kg of saffron petal extract, 5) basic diet + 1% pistachio husk biochar + 500 mg/kg saffron petal extract. Results: Hydroalcoholic extract of saffron petals and biochar caused a significant change in growth performance parameters (p<0.05). By adding saffron extract and biochar to the diet, the pH of the intestinal contents decreased. A significant increase in plasma IgG and IgM levels and a significant decrease in plasma IgA levels were observed with adding saffron petal extract and biochar to the diet. Adding biochar to diets resulted in increased levels of total protein, albumin, globulin, and decreased albumin/globulin ratio, aspartate transferase, and urea (P < 0.05). Saffron petal extract and biochar increased HDL plasma level (P = 0.0085) compared to the control. Quails receiving biochar and saffron extract showed a decrease in the colonization level of total bacteria including Lactobacillus, E. coli, coliform and Salmonella compared to the control (P< 0.05). Conclusion: The use of 1% biochar and 500 mg saffron petal extract in the diet can be a useful supplement for quails, which increases intestinal health,  and improves performance, blood parameters and the immune system. These results indicate that biochar and saffron petal extract can act as effective and environmentally friendly additives and contribute to productivity, sustainability, and cost reduction in poultry systems.