<b>Apparent digestibility of dry matter and crude protein; and digestible energy of some alternatives ingredients by Nile tilapia <em>Oreochromis niloticus</em></b> - DOI: 10.4025/actascianimsci.v26i3.1798

Abstract

This research aimed to determine the apparent digestibility of six energetic ingredients: ensiled high-moisture corn, raw oats, urucum, manioc flakes, algoroba and alfafa hay and, five proteic ones: soybean, coconut meal, leucena, alcohol yeast and dehydrated milk. 12 purified diets were formulated including these ingredients and one as a reference. All diets were supplemented with 0.01% of chromic oxide as marker. 240 Nile tilapia juveniles, with 100.00 ± 10.0g average weight were stocked in cages (10 fish/cage) for feeding and feces collection. During the feeding time (0800 AM - 0530PM) these tanks were kept in 250L aquaria, one for each treatment, and fish were fed ad libitum. After that they were transferred to 300L aquaria adapted for feces collection, where they stayed until next morning. The apparent digestibility coefficient (ADC) was determined based on chromic oxide concentration on diet and feces. It was concluded that, among the energetic ingredients, the manioc flakes and ensiled high-moisture corn showed the highest ADC for dry matter and crude protein and the best value for digestible energy; although the raw oats had showed good ADC for dry matter and crude protein. it did not prove to be a good energetic source for Nile tilapia; algaroba showed to be a good source of digestible energy; and, among proteic ingredients, the dehydrated milk, alcohol yeast and coconut meal showed the best ADC for dry matter and crude protein and also the highest values for digestible energy; leucena and soybean showed the worst ADC for dry matter and crude protein and the lowest values for digestible energy.