The Influence of Supplementing Broiler Chickens With Humic Acid or Biochar as Natural Growth Promoters on Their Productive Performance, Nutrient Digestibility, and Physiological Performance

Abstract

Study aimed to assess effects of humic acid/biochar on broiler production index, lipid profile, antioxidants, carcass traits, and economic efficiency. A total of 180, 7day-old, unsexed broiler chicks (Cobb 500) were divided into five experimental groups (36 chicks each), each with six replicates (6 chicks each). The first group was fed the basal diet and served as control; while the 2 nd and 3 rd groups were fed the same basal diet supplemented with 1.00 and 2.00 g of humic acid (HA) / kg diet, respectively; the 4 th and 5 th groups were fed the basal diet supplemented with 1.00 and 2.00% of biochar (BC), respectively. The rearing period extended to 35 days. Birds supplemented with HA and BC at varying levels showed significantly higher body weight (BW) and gain (BWG) compared to the control. The group with 1.00 g HA/ kg diet and 2% BC had the best BW and BWG. These supplements also improved feed conversion ratio (FCR) and economic efficiency, with 1 g HA/ kg diet and 2% BC showing the highest production index. Adding HA and BC to the diet improved crude protein (CP) and ether extract (EE) digestibility (P≤0.05). Additionally, supplementation increased dressing percentage and reduced abdominal fat compared to the control. Dietary supplementation in broiler chickens increased blood parameters (RBCs, hemoglobin, PCV, WBCs and lymphocytes), total protein, globulins, and thyroid hormones. It also reduced serum lipids and oxidative stress markers, while enhancing antioxidant indices and immune response (IgA, IgM, IgG, LTT and phagocytic activity). Moreover, it decreased harmful bacterial count and boosted beneficial bacteria count. In conclusion, supplementation of broilers with HA and BC improved growth performance, nutrient digestibility, immune response, and gut health.