Effects of hybrid giant napier Pennisetum sinese Roxb and formulated feed on growth and nutrient compositions in muscle of grass carp Ctenopharyngodon idellus
MAO Dong-dong1，2， ZHANG Kai2， OU Hong-xia2， XIE Jun2， WU Yin1，WANG Guang-jun2， YU De-guang2， XIA Yun2
1.College of Fisheries and Life Science， Dalian Ocean University， Dalian 116023， China； 2.Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation， Ministry of Agriculture， Pearl River Fisheries Research Institute， Chinese Academy of Fishery Sciences， Guangzhou 510380，China
Abstract: Grass carp Ctenopharyngodon idellus with body weight of(2.0±0.1)kg were reared in a circular indoor cement pool with a radius of 5 meters and fed separately extruded feed and diet containing hybrid giant napier(Pennisetum sinese Roxb)with triplication to investigate the improved effect of dietary hybrid giant napier on growth and nutrient compositions in muscle of grass carp.The results showed that there were significantly lower weight gain rate， condition factor， viscera-somatic index and hepato-somatic index in the grass carp fed the diet containing hybrid giant napier than in the fish fed the formulated feed(P＜0.05)， with significantly higher ratio of eviscerated body weight to total body weight in the grass carp fed the diet containing hybrid giant napier than in the fish fed the formulated feed(P＜0.05).There were no significant differences in approximate composition， mineral elements， amino acids and fatty acids(except for lauric acids)in muscle between the fish fed the formulated feed and the fish fed the diet containing hybrid giant napier(P＞0.05).There were almost the same amino acids composition including 16 amino acids in grass carp in the two groups，accounting for 19.53%and 19.33%，respectively.The grass carp fed the diet containing hybrid giant napier had the essential amino acid index of 83.85 and the fish fed the formulated feed had the essential amino acid index of 83.67， within the FAO/WHO standards.Nineteen fatty acids，primarily palmitic acid， oleic acid and linoleic acid， were found in muscle of the grass carp fed the two diets， with∑n-3 PUFA/∑n-6 PUFA ratio of 25.80%in the fish fed the diet containing hybrid giant napier and 22.56%in the fish fed the formulate diet.The findings indicated that the grass carp fed the diet containing hybrid giant napier had higher dressing rate and better body type than the fish fed the formulate diet did，corresponding with the demand of commodity market.
2018, Vol. 33 
