Y.A. Patwary
Faculty of Fisheries, BAU, Mymensingh - 2202, Bangladesh
B.S. Sarker
Department of Fisheries and Marine Science, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh
M. Belal Hossain
Department of Fisheries and Marine Science, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh; Biology Group, Faculty of Science, University of Darussalam, BE 1410, Brunei
M.H. Minar
Faculty of Fisheries, BAU, Mymensingh - 2202, Bangladesh
M. Shamsuddin
Faculty of Fisheries, BAU, Mymensingh - 2202, Bangladesh
Mechanical effects, Quality feed, Sish, Aquatic organisms, Manufacturing
Faculty of Fisheries, BAU, Mymensingh
Animal Health and Management
Sample collection: Samples were collected at randomly during two manufacturing stages (after final mixing and finish product) and named after ‘Final Mixer’ and ‘Finished Feed’ from a renowned feed manufacturing company named Globe Agro vet ltd. Another sample was formulated by using the industrial proportion on the dry basis of selected feedstuffs and used as ‘Control Mixer’. Samples were collected from all three batches as batch 01, batch 02 and batch 03. The samples were collected from June to September 2011. Analytical study: The samples were analyzed in the Laboratory of Fish Nutrition, Department of Aquaculture, Bangladesh Agricultural University (BAU). Determination of moisture: Moisture contents in wet samples were estimated by following Oven method. Materials needed for the experiment are analytical balance (METER AJ 100), drying oven, porcelain crucible and desiccators. Different stages include (1) weighing known sample in to a trade crucible, (2) drying in an oven at 105-110°C until the weight of the sample becomes constant; (3) cooling the dried sample in desiccators before interval weighing and (4) recording the final weight of the dried sample. Determination of ash: This method was used to determine ash content in feedstuffs by calcinations. Materials include (1) porcelain crucibles, (2) crucible furnace and (3) dryer. Determination is done by placing (2.5-5 g) sample in a crucible previously calcined and brought to constant weight and then placing the crucible in a furnace and heat at 550°C for 12 h and leaving to cool and transferring to a dryer. Finally, the weight of the crucible is taken again with the ash. Determination of protein: Protein was determined by Kjeldhal’s method. Reagents used were (1) mercuric oxide, (2) potassium sulphate or anhydrous sodium sulphate, (3) sulphuric acid (98%), (4) paraffin wax, (5) 40% solution of sodium hydroxide, (6) 4% sodium sulphate solution, (7) boric acid indicator solution, (8) standard solution of 0.1 N chlorohydric acid and equipments were (1) Kjeldhal digestion and distillation apparatus, (2) 500 mL Kjeldhal flasks, (3) 250 mL Erlenmeyer flasks, (4) glass beads. The method is done by weighing out 1 g of sample and placing in the Kjeldhal flask, adding 10 g of potassium sulphate, 07 g and 20 mL concentrated sulphuric acid. Then placing the flask tilted at an angle in the digester, bringing to the boiling point and retaining until the solution is clear; continuing to heat 30 min or more. Then leaving to cool, gradually adding approximately 90 mL distilled, de ionizing water and when cold adding 25 mL sodium sulphate solution and stirring. Adding one glass bead and 80 mL of 40% sodium hydroxide solution, keeping the flask tilted where two layers will form. Then the flask quickly connect with the distillation unit, heating and collecting 50 mL of distillate containing ammonia in 50 mL of indicator solution. At the end of distillation, removing the receptor flask, rinsing the end of the condenser and titrating the solution with standard chlorohydrate acid solution. Determination of fat: Fat can be conveniently determined by extracting the material paste with light petroleum (petroleum sprit B.P 40°C) in a soxhlet type extractor and the extract is weighted after careful recovered of the solvent. It is advisable to extract the sample first and then bound fat can freely extracted by the extracting solvent. Reagents include (1) 90% alcohol, (2) petroleum ether (B.P40°C-60°C), (3) Anhydrous sodium sulphate. Determination was done by weighing of the empty, cellulose thimble was taken. Then it was weighted the crushed and pasted sample. The soxhlet apparatus was set in a water bath and placed the thimble with sample in to the extractor. The whole extraction was accomplished by two phases. Alcohol extraction: Fat were extracted with 99% alcohol. After alcohol extraction, alcohol was recovered from the flask by distillation. After completed recovery of alcohol the thimble and content was heated slowly to vaporize trace alcohol present in the thimble content. Then the petroleum ether was added in to it. Petroleum ether extraction: The soxhlet apparatus was again setup in the water bath and petroleum ether (B.P40°C-60°C) was added and continued as in alcohol extraction. Alcoholic extract after recovery of alcohol was dissolved in ether extractive. Then the mixed extract was taken in a separating funnel was washed with hot water. When the oil ether solution was separated from water layer a quantity of anhydrous sodium sulphate was added to remove the bound water present in ether solution. After a while the clear oil ether solution was taken in previously round bottle flask. The ether was recovered by distillation. Then the fats were dried at 100°C in an oven and cooled in desiccators. Heating and cooling were continued until constant weight was as curtained. Determination of lipid: The lipid were extracted from the sample with petroleum ether and evaluated as a percentage of the weight before the solvent was evaporated. Reagents and materials include petroleum ether, soxhlet extraction apparatus, laboratory kiln set at 105°C, dryer, extraction thimbles. The determination is done by removing extraction flasks from the kiln without touching them with the fingers, cooling in a dryer and weighing. Weighted (3-5) g dry sample was taken, handled with tongs and placed in the extraction unit. Connect the flask containing petroleum ether at 2/3 of total volume of the extractor. Brought to boil and adjust heat to obtain about 10 refluxes per hour. The length of the extraction will depend on the quantity of lipid in the sample. Very fatty materials will be taken 6 hours. When finished, evaporate the ether by distillation or in a roto evaporator. Cool the flasks in a dryer and weighted them to within mg. the defatted sample can be used to determine crude fiber. Determination of crude fiber: Reagents used are sulphuric acid solution 0.255N; sodium hydroxide solution 0.313N free of sodium carbonate; antifoam (octyl alcohol or silicone); ethyl alcohol at 95% (v/v); petroleum ether; chlorhydric acid solution at 1% (v/v). Materials include 600 mL flat bottomed balloon flask with roughened neck; condensation unit for flask; 11 kitazato flask; buchner funnel; filtration; crucible; rubber cones; Whitman ash less filter paper; 500 mL retort; dryer; laboratory kiln; crucible furnace. Method was done by weighing out 2-3 g of defatted, dry sample within milligrams, placing in the flask and adding 200 mL boiling sulphuric acid solution, attaching the condenser and bringing to boiling point in one minute.
Pakistan Journal of Biological Sciences, 16: 865-870; ISSN 1028-8880
Journal