An Investigation effect of seaweeds as shrimp -feed ingredient for growth performance of Litopenaeus vannamei

Abstract

In this project, The nutritional effects of Sargassum illicifolium Chabahar bay-Oman Sea, on growth and survival rates of whiteleg shrimp (Litopenaeus vannamei) were studied. The seaweed collected from 6 coastal area, rinsed, dried, powdered and measured the nutritional values in laboratory for surveying statistically. According to the high nutritional value of Tis coastal seaweed, this variate seaweed powder, replaced with protein resources (fish meal and Soy and Wheat) of whiteleg shrimp feed which was formulated by Havorash feed factory of Boshehr in four treatments (A: as control without any replacement) B: with 5%, C: 10 % and D: 15% seaweed replacement, each with three replicates in order to obtain isonitrogenus 33% CP., and Isocaloric (13% fat and 15% carbohydrate) feed. The weighed milled ingredients were carefully mixed using a laboratory food mixer. The mixtures were primed with 30% hot water to yield a suitable pulp. Wet diets were made into 2 mm pellet size and dried at 40 °C in a drying cabinet and maintained in standard condition which was used according to daily need shrimp, calculated by each 10 days biometry. Water stability and absorbtion capacity of the pellets in sea water were measured and compared statistically. Juvenile shrimps (Initial body weghit =3 g) brought from Jask hatchery, acclimazed for one week in chabahar hatchery condition and feeding daily 3-5% body weight. Abiotical parameters and weight and lenght biometries were measured two days and 10 days, repectively. After 45 days and final biometry, FCR, CF, SGR, caracas analysis, muscle colourimetery with HPLC were done, tasted with pp Plot for determining the parametric data and statistically differences using one – way ANOVA, Duncan test of SPSS software. The Tis coastal seaweed with 9.8% CP, 2% lipid and 23% carbohydrate had higher nutritional value compared to the other gathered seaweed. Also amino acid and fatty acid profiles, vitamins and minerals were measured in all seaweed samples each, with three replications. As result, The water stability of D feed treatment in seawater (98%) and C (97%) had statistical differences with A and B (95% stability) (P<0.05). Water absorption capacity of feeds after one hour immersion in seawater showed significance difference between D (110%) and three others, C(100%), B(85% and control(80%) (P<0.05). Shrimp growth data, after the end of experiment revealed that seaweed feed treatments had no any differences with control group significantly. However, the absolute growth rate datas of D treatment were higher than others and the lower weight and lenght were measured in control group shrimp. FCR had difference between seaweed treatments and control statistically. There are no any differences between caracas lipid treatments (P>0.05) but Cholestrol content of, showed differences between all, significantly (P<0.05) which was the highest (121.68±12.12) in D and the lowest in A (147.92±11.02). Feed treatment D and C performed colour changes pink partial orang and pink in shrimp muscle with no any difference compared to white and none colour in shrimp were fed B and A feed treatments . It seems this colour changing can be playing a major role in market accebtability.