Effects of dietary phytase (PHY) levels on nutrient digestibility, mineral absorption and growth performance of Oreochromis niloticus fingerlings fed Moringa based diets

Abstract

PHY is very important enzyme in fish feed for the digestion of plant based diets as they have chelated compounds i.e. phytic acid. A seventy days experiment was conducted to study the effects of phytase (PHY) supplemented Moringa oleifera based diets on the growth efficiency of Tilapia fingerlings. Tilapia fingerlings were fed with a diet made up of mixture of Moringa seed and leaf meal (MSM and MLM). Anti-nutritional agents present in plant based products, decrease the nutrient edibility, utilization of minerals and shows negative impact on development. Seven isonitrogenous and isoenergetic diets were prepared by the addition of PHY (0, 500, 650, 800, 950, 1100 and 1250 FTU per kg) in Moringa based diet and 1% of chromic oxide as indigestible marker. Fingerlings were fed @4% of live wet weight two times daily and faeces were collected and analyzed at the end of the trial. Growth parameters were also checked on fortnightly basis. Based on outcomes, improvement in growth i.e., weight gain WG (24g), weight gain percentage (356%), FCR (1.21), SGR (1.69), nutrient digestibility (CP; 74%, EE; 70%, and GE; 69%) and absorption of mineral (Ca; 72%, Na; 71%, K; 71% and P; 75%) was noticed when fingerlings were fed at 950 FTU per kg level based diet as compared to control and other test diets. It was additionally noticed, that PHY addition diminished the release of nutrients and minerals through faeces that was resulted in decreased water contamination. On the basis of these results, it was concluded that addition of PHY @ 950 FTU per kg level is very useful to formulate cost-effective and eco-friendly fish feed by utilizing Moringa-derived products as compared to control and other test diets.