مقایسه تاثیر استفاده از پودر کرم توبیفکس (tubifex tubifex) پرورشی و تجاری در جیره غذایی بر شاخص‌های رشد و ایمنی ماهی آنجل (pterophylum scalare) قبل و بعد از تنش هوا

کرم توبیفکس (tubifex tubifex) یکی از انواع غذاهای زنده در صنعت آبزی‌پروری است که با توجه به ارزش غذایی فراوان آن از لحاظ پروتئین، چربی خام، انواع اسیدهای آمینه و اسیدهای چرب ضروری(w6وw3) و استفاده این ماده غذایی در غذای ماهیان زینتی باعث بهینه‌سازی روند رشد، بازماندگی زیاد و بهبود سیستم ایمنی فراهم می‌شود.در این تحقیق اثر استفاده از پودر کرم توبیفکس پرورشی، توبیفکس تجاری و غذای پلت بر عملکرد رشد و شاخص‌های ایمنی ماهی آنجل در طول مدت 63 روز بررسی شد. ماهیان در سه تیمار و سه تکرار با تراکم 15 قطعه در9 آکواریوم 20 لیتری با متوسط وزن اولیه بچه ماهیان به مقدار21/0±55/19 گرم ذخیره‌سازی و به‌صورت کاملاً تصادفی توزیع شدند. غذادهی به‌صورت روزانه در سه نوبت 7 صبح، 13 ظهر و 20 شب و به میزان 3 درصد وزن بدن انجام گرفت. نتایج درانتهای دوره پرورش نشان داد که تغذیه غذای حاوی پودر کرم توبیفکس پرورشی باعث رشد بیشتر (02/0±80/1درصد وزن بدن در روز) نسبت به غذای حاوی توبیفکس تجاری (31%+) و غذای حاوی پلت (27%+)شد(05/0 >p). وزن نهایی ماهیان تغذیه شده با غذای حاوی پودر توبیفکس پرورشی به‌طور معنی‌داری به میزان 30 درصد و 26 درصد نسبت به ماهیان تغذیه شده با غذای حاوی توبیفکس تجاری و غذای حاوی پلت بیشتر بود.تغذیه غذای حاوی پودر توبیفکس پرورشی با ضریب تبدیل بهتر (03/0±44/1) و به‌ترتیب 11 درصد و 19 درصد نسبت به تغذیه غذای حاوی پلت و غذای حاوی توبیفکس تجاری همراه بود (05/0 >p). ایمونوگلوبین کل، لیزوزیم و فعالیت کمپلمان بعد از تنش هوا در تیمار تغذیه غذای حاوی پودر توبیفکس پرورشیبه‌طور معنی‌داری بیشتر بود. همچنین میزانفعالیت آنزیم‌های گوارشی (آمیلاز، پروتئاز و لیپاز) در ماهیان تغذیه شده با پودر کرم توبیفکس پرورشی بیشتر بود. مقدار دو آنزیم آسپارات آمینوترانسفراز(ast) و آلانین آمینوترانسفراز(alt) در تیمار حاوی پودر کرم توبیفکس پرورشی نسبت به دو تیمار دیگر کمتر بود (05/0 >p). بر اساس نتایج به‌دست آمده می‌توان گفت که تغذیه ماهی آنجل با غذای حاوی پودر کرم توبیفکس پرورشیبه‌ویژه در زمان شروع تغذیه فعال می‌تواند باعث بهبود رشد و برخی شاخص‌های ایمنی اختصاصی و غیر اختصاصی شود.

Comparison of Cultivated Tubifex Worm (Tubifex tubifex) Powder and Commercial Tubifex Worm on Growth Performance and Immunity Indices in Angel Fish (pterophylum scalare) Resistance to Air exposure Challenge Stress

Introduction The aquaculture industry in the world, with an 8milliondollar transaction rate, has 8% growth annually. It also has the most valueadded rate among different fishery activities based on the food and Agriculture Organization (FAO). The angelfish belonging to Cichlidfamily, is known as a famous species in this industry. This fish feeds on various live feedstuffs. Regarding the significance of suitable feedstuffs in aquafeed industry, the live feeds used to provide nutritional requirements, immunity tuning and stimulation will be of important. Tubifex worm, containing considerable crude protein, diverse sorts of amino acids and essential fatty acids, has a deserving role and checking the nutritional value of Tubifex worm with aim of improving the growth performance, boosting immune responses and survival rate, reducing expenditure cost and increasing productivity is so crucial. The objective of the current experiment was to compare the effect of the cultured and commercial Tubifex worm powder in the diet of juvenile angelfish on growth performance and immune responses.;Materials and methods The experimental rations included 3 rations: 1) control ration as pellet 2) commercial Tubifex powder as freezedried food and 3) the rations containing massproducedTubifex as freezedried food. Onehundred thirty fiveAngel fishes with an average initial weight of 0.2± 0.5 gr were tested for 63 days. The fishes were placed randomly into nine 920 litercapacity of 15 fishes. The average temperature was (27±1˚C), pH (7.5±0.1) and dissolved oxygen (7.68±0.35) was regulated according to required conditions.The length of lightdark cycles was considered 14 and10 hours, respectively.The fishes were fed 3% body weight in three times a day (7, 13 and 20). Biometry was conducted at 1st, 31st and 63rd days and the criteria related to the growth performance, nutrient utilization efficiency and survival rate were computed. ;At the end of the experimental period, five samples were taken from each aquarium, exposed to the air challenge for 3 min and bleed 3 h after challenge. After that, biochemical analyses including trypsin, amylase and lipase were measured by using benzoylarginine pnitroanilide substrate, starch and olive oil as substrate, respectively through titration method. At the end of the experimental period, total immunoglobulin, lysosome and complement, liver enzymes including ALT and AST were measured by kinetic enzymatic method and the microbial parameters including (plate count agar, and lactobacilus conut were measured. Chemical analysis of experimental diets including crude protein by Kjeldahl method, crude fat by Soxhelt extractor and ash by electrical furnace were measured. Normality Test of was done by Shapiorwilk test. Analysis of alterations in growth performance, nutritional and biochemical factors were done by oneway analysis of variance (ANOVA) and comparing means based on Duncan multiple test using SPSS software, version19.0.;Results and DiscussionThehighest rate of final weight (about 30%), initial length (about 14%) and the rate of special growth (about 27%) were belonged to the angel fishes fed on the diet containing cultured Tubifex. The activity of the immunity parameters including total immunoglobulin, lysosome as well as complement were also significantly higher in the treatment with the diets containing Tubifex after air exposure challenge. The activities of the lipase, protease and amylase increased in the culturing Tubifex treatment in compared with two other ones.The number of the intestinal lactobacillus indicated that the most colonies forming unit of lactobacillus was significantly higher in angel fish fed the diet containing cultured Tubifex treatment. The results indicated that the angel fishes fed on the cultured Tubifex showed higher weight increment, special growth rate, survival rate as well as better nutrient utilization efficiency which may be attributed to the existence of higher rate of protein, unsaturated fatty acids;Improvement of the immunity in fish fed the diet containing cultured Tubifex can be related to the role of lysosome as an important factor in natural perseverance for fishes, immunoglobulin as an important factor in antibody secretion as well as complement which has a basic role in acquired natural immunity for the fishes. The enzymes ALT and ALP which have an important role in using amino acids in oxidation process The increase of intestinal LAB count in angel fish fed the cultured Tubifex can be enhanced absorbing nutrients, disease resistance and finally, higher growth performance Considering the higher mortality rate among the larvae in the first 2030 days and the initial time of the active feeding because of changing the nutritional modes, use of Tubifex worm powder as a live food may be effective in better growth function, external form as well as promotion of immunity system for the fishes.;Conclusion Feeding the angel fishes on cultured Tubifex worm powder especially in the initial steps of the active feeding may result in improvement in growth performance and some specific and nonspecific immune responses.