Effect of Fennel Seed Supplementation into Broiler Diet on Their Growth, Physiological, and Immunological Performance

Abstract

The current research sought to determine the impact of dietary fennel seed (FS) inclusion on broiler chickens' productive performance, slaughter traits, biochemical components, cholesterol profile, stress indicators, and immune status. Four hundred male Cobb500 broiler chickens were grown on floor pens and fed a mash-based corn-soybean diet from one day to 21 days old. From 22-42 days of age, the birds were divided into four experimental groups (10 replicate pens × 10 chicks each) in which the birds were fed on a finisher-based diet supplemented with 0, 10, 20, and 30 g/kg FS powder (FS0, FS10, FS20, and FS30 groups, respectively). Data were analyzed using one-way ANO-VA with a polynomial contrasts test to explore the linear and quadratic trends of the FS increasing levels in broiler diets. The overall amount of feed consumed was unaffected by the FS diets. Still, increasing dietary FS levels enhanced the broilers' final weights, gains, and feed-to-gain ratios (p < 0.05). As the dietary FS levels increased in broiler diets, weights for the carcass yield, breast, liver, and spleen increased substantially (p < 0.05). The plasma total protein and triiodothyronine hormone levels were remarkably (p < 0.05) enhanced by adding FS to broiler meals. At the same time, the concentrations of alanine transferase, aspartate transferase, and uric acid were significantly (p < 0.05) lowered. Additionally, the triglycerides were dramatically (p < 0.05) decreased while the high-density lipoprotein composed a higher proportion than the low-density-lipoprotein of the total cholesterols (p < 0.05). Additionally, as dietary FS levels increased, plasma corticosterone (CORT) and malondialdehyde (MDA) levels as stress markers in broilers reduced significantly (p < 0.05). On the other hand, adding FS to broiler diets considerably (p < 0.05) improved both the humoral and cellular immunity, as determined by the antibody (AB) titers and the phytohemagglutinin-wattle reaction (PHA-WR), respectively. It was observed that most of these measures showed a linear trend response to the rise in FS levels up to 30 g/kg of broiler diets. The FS30 group presented the lowest values of CORT and MDA by approximately 21% and 15%, respectively, and the maximum levels of AB titer and PHA-WR by 38% and 3-fold, respectively. These findings suggested that dietary supplementation with FS would be a useful nutritional strategy to enhance poultry production.