اثر لسيتين سويا بر شاخص‌‌هاي رشد، تركيب شيميايي، فعاليت آنزيم‌‌هاي گوارشي و ريخت‌‌سنجي روده ماهي آزاد خزر (Salmo trutta caspius)

Effect of soybean lecithin on growth indices, body composition, digestive enzymes activities and intestinal histomorphometery of Caspian Salmon (Salmo trutta caspius)

مطالعه حاضر با هدف ارزيابي اثر لسيتين سويا بر شاخص‌‌هاي رشد، تركيب لاشه، فعاليت آنزيم‌‌هاي گوارشي و ريخت‌‌سنجي ‌‌روده پيش مولدين ماهي آزاد درياي خزر انجام شد. براي اين منظور تعداد 90 عدد ماهي آزاد (10±350گرم) بصورت تصادفي در سه تيمار (هر كدام با 3 تكرار) تقسيم شدند. ماهيان گروه اول (شاهد) با غذاي پايه مركز، گروه دوم غذاي پايه به همراه 12% روغن سويا، گروه سوم غذاي پايه بعلاوه 6% روغن سويا و 6% لسيتين به مدت 90 روز تغذيه شدند. شاخص افزايش وزن بيانگر برتري آماري تيمار 3 نسبت به تيمارهاي شاهد و 2 بود. همچنين شاخص ضريب تبديل غذايي (FCR) در تيمار 3 فقط با تيمار شاهد اختلاف معني‌‌داري داشت (05/0≥p). رطوبت لاشه ماهيان تيمارهاي 2 و 3 با شاهد داراي اختلاف معني‌‌داري بود (05/0≥p)، ولي در محتواي پروتئين و چربي بين تيمارها اختلاف معني‌‌داري نداشت (05/0

The present study conducted to evaluate the effects of soybean lecithin on growth indices, body composition, digestive enzymes activities and intestinal histomorphometry of Caspian salmon. Ninety fish (350g ± 10) were randomly divided into three treatments with three respective replicates. The first treatment (control group) was fed with commercial feed, while the second group received diet supplemented with 12% soybean oil, and the third one received feed supplemented with 6% soybean oil and 6% soybean lecithin for 90 days. Weight gain was indicative of the statistical superiority of treatment 3 over control group and treatment 2. In addition, FCR of treatment 3 was only significantly different from control group (p≤0.05). There were significant differences regarding moisture content of treatments 2 and 3 in compare to control group (p≤0.05), however, protein and lipid contents of treatments were not significantly different (p≤0.05). Furthermore, energy contents of treatments 2 and 3 were significantly different (p≤0.05). Digestive enzymes activities (protease, lipase and amylase) of treatment 3 significantly differed from treatment 2 and control group (p≤0.05). Morphometric characteristics of intestine including epithelium thickness and external muscle thickness of treatments 2 and 3 were significantly different from those of control group (p≥0.05). In conclusion, supplementing Caspian salmon diet with 6% soybean lecithin improved growth and some physiological parameters of the fish.