Determining the Optimal Pattern of Vitamin Supplementation in Diets Containing Wheat Waste by Estimating the Performance and Immune Responses of Broiler Chickens

Introduction: In the past, vitamins were considered as unknown growth factors, but during the twentieth century, their structure and nature were gradually discovered. These compounds are necessary to maintain the integrity of the tissues and general health of the body. Broiler chickens are unable to synthesize vitamins (except vitamin C) or have the ability to make limited amounts of them (group B and K2). For this reason, vitamins should be added to broiler feed as a supplement. Vitamins interact with other nutrients in various ways. The main reference for vitamin requirements in broilers is the National Research Council (NRC, 1994). The recommended amounts ensure conditions where there are no severe deficiencies. Applying the NRC recommendations cannot guarantee the genetic potential of today's birds. Because these values were taken from old studies and using pure feeds in laboratory conditions. Due to the dependence of Iran's poultry industry on the import of vitamins, unfortunately, in recent years, few studies have been conducted in the country on the appropriate pattern of adding vitamins to the diet of broiler chickens. Therefore, it is necessary to examine the lower levels than the recommendation of the Ross 308 strain catalog (Aviagen, 2019) as the dominant strain of the country and to propose an optimal model for different regions that does not have a negative effect on the performance and safety traits and to reduce the need to import this strain. It will also follow the products.Materials and Methods: The aim of this study was to determine the optimal pattern of vitamin supplementation in diets based on corn, wheat waste and soybean meal on production traits, carcass characteristics and immune responses of broilers from 1 to 42 days of age in Fars province. A total of 500 Ross 308 broilers with similar mean weight (mixed sex) were distributed in a completely randomized design with five treatments, five replications and 20 chickens per replication. Experimental treatments included five levels of vitamin supplementation: 1) control (100% of the recommended values of Ross 308, 2019 strain catalog), 2) 90% of the recommended values of Ross 308, 2019 strain catalog, 3) 80% of the recommended values of Ross 308, 2019 strain catalog, 4) 70% of the recommended values of Ross 308, 2019 strain catalog and 5) 60% of the recommended values of Ross 308, 2019 strain catalog. At the end of each period, the feed consumption and body weight of the birds were re