Study Of Narasin On Growth-promoting Function And Security Of Common Carp (Cyprinus Carpio)

This paper was involved in determining the effect of dietary narasin on growth performance of common carp and security evaluation during farming common carp. It consisted of three experiments. In experiment I and II, 4g and 60g common carp were used, respectively. They were fed to diets supplemented with 0, 10, 20, 40, 80 and 160 mg/kg narasin, respectively. Subsequent weight gain rate, specific growth rate and feed conversion rate were determined. Additionally, the number of red blood cell and white blood cell, the contents of hemoglobin, glucose, total protein, albumin, urea, creatinine, cholesterol, triglycerides, the activities of aspartate amininotransferase (GOT), alanine aminotransferase (GPT) and alkaline phosphatase (ALP) in the serum, morphometrical parameters were all measured and histopathology of visceral organs observed in experiment II. Experiment III was conducted to determine the effect of dietary narasin levels (0, 20, 40, 120, 360, 1080 and 3240 mg/kg, respectively) on weight gain rate, specific growth rate and feed conversion rate of juvenile carp (initial mean weight: 60g), and apparent digestibility coefficients of dry matter, protein and lipid were obtained in 20, 40, 120 and 360 mg/kg of dietary narasin levels. Results were summarized as follows:1. Weight gain rate and specific growth rate increased by 27.4%-81.0% and 0.18%-0.36%, respectively, in 4g common carp and by 3.8%-9.5% and 0.1%-0.5%, respectively, in 60g common carp and feed conversion rate declined by 0.05-0.25 and 0.21-0.63 for 4g and 60g common carp, respectively, when common carp were fed to diets containing 10 mg/kg to 160mg/kg narasin for 63d. Optimal dietary narasin levels were determined to be 20mg/kg-80mg/kg. Dietary narasin levels from 360mg/kg to 3240 mg/kg resulted in reduced weight gain rate and specific growth rate, and increased feed conversion rate of juvenile carp (initial mean weight: 60g) during 21 days.2. Apparent digestibility coefficients of crude protein and lipid significantly increased when carp were fed to diets containing 20mg/kg-40mg/kg narasin.3. 10mg/kg-80mg/kg of dietary narasin markedly elevated the number of red blood cell and white blood cell, and the content of hemoglobin, and promoted physiological function and metabolism intensity of juvenile carp (initial mean weight: 60g) for 14d. Meantime, the concentrations of glucose, total protein, albumin, cholesterol, triglycerides and the activities of GOT, GPT and ALP also increased, but the contents of urea and creatinine in the serum declined, indicating that the nutritional absorption of common carp was improved and that the retention rates of protein and nitrogen accelerated. However, , when the experiment continued for more than 42d or 56d, all of...