The effect of using different levels of rapeseed meal on internal organ weight and secretion of thyroid hormones in broilers

Abstract As rapeseed meal production is increasing in IRAN, this research is designed to investigate the possibility of replacing soybean meal with rapeseed meal as well as the anti nutrient effects of rapeseed meal in broiler diet. In this research rapeseed meal in five different levels 0%, 25%, 50%, 75%, and 100% was used in the ration of broilers in place of soybean meal. The study was conducted on 500 one-day old chicks by completely randomized design (CRD) with 2×5 factorial arrangement and 4 replicates and 25 birds in each replicate. The birds were fed with experimental diet for 8 weeks. At the end of eight weeks, one male and one female bird were randomly selected from each replicate and slaughtered and the heart, liver, and pancreas were taken for examination. While slaughtering a sample of their blood was also collected to measure the level of T3 and T4 hormones. The results showed that the use of rapeseed meal didn’t have a significant effect on secretion of T3 and T4 hormones, heart weight, and pancreas weight percentage. With the increase in consumption of rapeseed meal the liver weight percent was increased significantly (p