Effects of dietary vitamin C supplementation on growth performance, carcass characteristics, gastrointestinal organs, liver enzymes, abdominal fats, immune response and cecum microflora of broiler chickens

Introduction: Increasing the concentrations of blood glucose leads to decrease appetite and decreased the concentration of stimulant in the hunger centre of the bird s hypothalamus and consequently, decrease feed intake. High intakes of vitamin C may alter the blood glucose concentration, although the evidence is contradictory. The aim of this study was to evaluate the effects of increasing vitamin C concentrations (0, 200 and 400 mg/kgDM) on performance, carcass and digestive organ characteristics, blood plasma components, liver enzymes, immune system, and cecal microbial flora of broilers. Material and method: The study was based on a completely randomized design with three treatments and four replicates of 10 chickens per pen. The study lasted42 days and started with 120 one-day-old male chickens of commercial Ross 308 strain. Treatments were compared usingDuncan s multiple-range test. Results and discussion: Chicks fed a diet containing 200 mg/kg vitamin C had the highest feed intake and weight gain as well as the best feed conversion ratio, the lowest cost per kilogram of live body and the best European production factor. The effect of vitamin C was significant on the weights of live body, featherless, full abdomen carcass, empty abdomen carcass, relative crop, and relative breast (P 0.05). Moreover, the highest increase was related to 200 mg vitamin C /kg diet. The effect of different levels of vitamin C on blood parameters and liver enzymes of broilers was not significant (P 0.05). In addition, the percentage of neutrophils and lymphocytes was significantly higher (P 0.05), and the highest percentage of neutrophils was also observed in chicks’ fed the level of 200 mg/kg vitamin C. The mean results of blood antibody titers against SRBC did not show a significant difference (P 0.05), except for 35 days of age, which was significant (P 0.05). Based on the results of the present study, the use of 200 mg/kg vitamin C to supplement the diet of Ross 308 strain broiler chickens is recommended. Conclusions. Blood parameters were insignificantly affected in vitamin C diet fed birds; nonetheless, the experimental diet improved the immune system of animals and reduced the fat content of ventricular area; thereby improving the quality of carcass meat. According to our observations, utilization of 200 mg vitamin C/kg diet is recommended as an antioxidant compound and inexpensive growth promoter.