Feed Peas in diets for shrimp tilapia and milkfish - Northern Pulse ...

experimental diets are presented in Table 1. All diets were formulated to contain 30% protein, 10% lipidand energy of about 394kcal/100g diet. Analyses however, showed that experimental diets contained 33%protein and 10% lipid, while the commercial milkfish feed control contained 37% protein and 9% lipid. Thebasal formulation contained fish meal, defatted soybean meal, meat and bone meal, and copra meal asdietary protein sources. The levels of feed pea incorporation tested were 0, 5, 10, 15, 20, 25, and 30% ofthe total crude protein. Dietary essential amino acid profiles (Table 2) were calculated based on analysesof ingredients and published data (NRC, 1977) and compared to that of requirements for milkfish juvenile(Borlongan and Coloso, 1993) which was used as the reference. Analyzed values of the essential aminoacids are likewise presented. No supplemental amino acids were added to the diets. Cod liver andsoybean oils served as lipid sources. Vitamin and mineral premixes were kept constant in all diets.Commercial feed peas of US origin were sourced from a local agricultural distributor. The whole dry peawas oven-dried at 60 0 C for 4 hours and finely ground to homogenized flour. No specialized ingredientprocessing method was used. Diets were prepared by first mixing all dry ingredients in the Hobart mixer.Oils were then blended with the dry ingredient mixture. An equal portion of bread flour was gelatinized bycooking in 600 ml water and added to the mixture. The semi-moist mixture was then passed through theHobart food grinder to form 2 mm diameter pellets. The pellets were dried in an air convection oven at40 0 C. The dry pellets were then ground, sieved to uniform sizes, and stored at 4 0 C until used for feeding.Experimental fish and feeding managementThe experiment was conducted at the Feed Development Section of the Aquaculture Department of theSoutheast Asian Fisheries Development Center (SEAFDEC/AQD), Tigbauan, Iloilo, Philippines. Hatcherybredmilkfish juveniles were acclimated for two weeks under laboratory conditions and to a dry diet (controldiet) prior to the experiment. The feeding trials were conducted in an indoor flow-through system. Sixty-litercapacity, oval fiberglass tanks containing 50L seawater with aeration were used. Milkfish juveniles (meanwt. = 0.42 g) were randomly distributed at a stocking rate of 10 fish per tank and in four replicate tanks pertreatment. Fish in each treatment were then fed three times daily at 0830, 1130, and 1400H at a feedingrate of 10% body weight per day for 12 weeks. Feeding ration was adjusted at every 3 weeks samplinginterval. Water quality parameters (temperature, salinity, DO, pH, ammonia, nitrite) were monitoredfollowing the methods of Strickland and Parsons (1972) to ensure water quality remained well within limitsrecommended for milkfish culture (Bagarinao, 1991).Statistical AnalysesSurvival, % weight gain, specific growth rate (SGR), food conversion ratio (FCR), and protein efficiencyratio (PER) were calculated and subjected to statistical analyses. Data were subjected to analysis ofvariance (ANOVA) and Duncan’s Multiple Range test (DMRT). Differences between means wereconsidered significant at P