An Analysis of the Physical Characteristics of DC-MSF (Destarched Cassava Maize Soybean and Fishmeal) Fish Feed

Abstract

Physical properties of fish feed are critical for ensuring structural integrity and efficacy of fish feed. Fish feeds are expensive and feed makers look for ways to produce less expensive feeds, ingredients used affect integrity of fish feed. Poorly prepared feed causes pellet disintegration, nutritional leaching and also lowers fish feed consumption. Quality of a fish feed depends mainly on its physical properties and feeds for fish species are selected based on the physical properties of feed. In this study, the physical properties of DC-MSF were assessed and compared to the control feed. Physical properties (diameter, height, volume and surface area before and after expansion, bulk and pellet density) of the two feeds were assessed. Diameter and height of DC-MSF were measured with Vernier caliper as well as diameter of Control feed. Volume and surface areas were calculated from results obtained from height and diameter. Measured pellets were kept in water for 10, 20 and 30 minutes and diameter and height recorded. Bulk density was assessed from weighing a 25ml of beaker with feed filled to the mark and calculated with a formula. Results indicated that DC-MSF had higher diameter measurements with highest increase in diameter after 10 minutes. Due to shape of the control (spherical), height was inaccessible but the highest height recorded was after 20 minutes for DC-MSF. The shape of DC-MSF (cylindrical) resulted in high mass of the feed and can lead to obesity in fish. Surface area to volume ratio was higher in DC-MSF than control feed which affect leaching of nutrient in water of feed. Control feed had higher expansion rate than DCMSF but DC-MSF obtained higher bulk and lower pellet density resulting in faster sinking rate of DCMSF and recommended, mass, height and surface area to volume ratio reduced.