بررسي تاثيرات سطوح مختلف پروتيين بر روي معيارهاي شاخص رشد بچه ماهي با بهره گيري از جيره نيمه خالص

A study on various protein levels on growth indices (SR, WG, RGR, FCR and PER) of Rutiluss frisii kutum, Kamenskii 1901(Advanced fry)

For improving natural potential resources of Caspian frisii kutum in southern Caspian sea (Iran); production of larger advanced fry in controlled condition are essential and this can not be achieved unless we have knowledge of nutritional requirements of advanced fry especially the protein levels. Until now there is not relevant information regarding nutritional requirements of Caspian f ri.sii kuturn; hence an experiment of 8 weeks duration was conducted on advanced fry in order to evaluate the protein Ievels.Three protein levels of 25%, 30% and 35% with isocaloric digestable energy of 3400 kcal/kg diet were formulated. One - hundred and eighty advanced fry (2g ± 0.6) were randomly distributed between nine fiberglass tanks of 400L capacity.Nutritional responses in term of WG and RGR were improved with increase of protein levels from 25% to 35% (p < 0.05) without indicating optimum beyond : to FCR and PER were not significant of treatments one and two (p > 0.05 ); however, they were significant with treatment three (p < 0.05).Fish carcass composition were significant and improved only at treatment three (p < 0.05) which indicating that body protein increasing while fat decreasing and showed flesh quality improving.