Effects of fennel and black caraway seeds and mannan-oligosaccharide prebiotic on performance, carcass traits, blood parameters of broiler chickens

This study was conducted to compare the effects of fennel (Foeniculum Vulgar), black caraway (Carum carvi) and prebiotic mannan-oligosaccharide on performance, carcass traits and blood parameters of broiler chickens. A total number of 160 one-day-old male broiler chicks (Ross 308) in a completely randomized design were divided into five treatments, four replicates and 8 chicks per replicate. The five experimental treatments were: 1-control diet or basal control (no additives), 2- adding 1 % fennel to basal diet, 3- adding 1 % caraway to basal diet, 4- adding mixture of 0.5 % nettle and 0.5 % caraway to basal diet and 5- adding advised commercial level of prebiotic (Fermacto; 0.2 %) to basal diet. The results showed that the birds fed diets supplemented with mixture of 0.5 % nettle and 0.5 % caraway or prebiotic had higher body weight during the whole experimental period compared with control group (P<0.05). Moreover, supplementation diets with 1 % nettle, mixture of 0.5 % nettle and 0.5 % caraway and prebiotic improved feed conversion ratio during the whole experimental period and decreased the blood levels of triglycerides, cholesterol and low-density lipoprotein (LDL) compared with control treatment (P<0.05). Prebiotic supplementation significantly decreased relative weights of abdominal fat and liver (P<0.05). The addition of 1 % craway to the diet also significantly increased the weights of thymus and bursa of Fabricius compared with 1% nettle and control treatments (P<0.05). This study showed that the inclusion of nettle and mixture of nettle and caraway, similar to including prebiotic, to the broiler diet can improve growth performance and decrease serum triglyceride and cholesterol concentrations.