اثرات مصرف سطوح مختلف تفاله لیموترش و کاهش انرژی و پروتئین جیره بر هورمون‌های مربوط به رشد، فراسنجه‌های خون و عملکرد جوجه‌های گوشتی

The aim of this study was evaluation the effects of energy and protein decreasing of diet with using of different levels of lemon pulp intake on growth related hormones, blood parameters and performance of broiler chickens. Lemon pulps used as a dietary replace for nutrient. A total 240 one-day old broilers (Ross 308) were randomly divided to 4 treatments (4 replicate with 15 birds per pen). Four experimental treatments supplemented with 0, 4, 8 and 12 percent of lemon pulp. At the end of experimental period, performance values were calculated and sera separated from blood samples were used for measurement of hormones level by ELISA technique and biochemical parameters by auto analyzer system. The results showed that the rations containing of lemon pulp had significantly decreased body weight in broilers at the end of starter and finisher periods (P<0.05). The use of lemon pulp in different levels decreased carcass yield, breast weight and abdominal fat weight (P<0.05). The use of lemon pulp caused to decreasing of cholesterol, triglycerides and LDL and increasing of HDL in the blood of broilers (P<0.05). The use of lemon pulp had no effect on growth hormone and insulin, but decreased thyroxin hormone (P<0.05) that this may be caused to decreasing basal metabolism rat and one reason for decline in growth. In this study, there were no mortality in any of the experimental treatments due to the exact control of the experimental hall and the observance of hygiene. According to the blood lipids and metabolic indicators reduced by pulp lemon intake and these effects caused of adjustment in metabolism of birds and healthy in blood parameters. Therefore, low levels of lemon pulp may be used for decreasing of the energy and protein concentrations in the broiler diets in order to prevention of the metabolic disorders in poultry with rapid growth.