Digestibility of Diets Micro-supplemented with Whole Chlorella vulgaris Beijerinck, 1890 in Hybrid Red Tilapia (Oreochromis mossambicus × O. niloticus)

Microalgae are rich in carotenoids, immunomodulating metabolites and other nutrients suitable as fish feed. Chlorella sp. has all the essential amino acids, and its micro-supplementation enhances fish performance. While there are several studies on the role of Chlorella sp., little information is known about its digestibility at micro-supplementation levels. The present study was aimed at investigating digestibility of diets micro-supplemented with whole Chlorella vulgaris Beijerinck, 1890 at different inclusion levels in hybrid red tilapia (Oreochromis mossambicus × O. niloticus). The experiment was carried out using whole C. vulgaris to determine the nutrient apparent digestibility coefficient (ADC) of the diet. A total of 84 hybrid red tilapia (105 ± 7 g) were assigned randomly into four groups with 21 fish each for a 21-day feeding trial. The treatment groups were; control (basal diet only), test diet I, II and III (basal diet + 1 %, 3 %, and 5 % C. vulgaris w/w, respectively). The result showed that micro-supplementation of C. vulgaris at all the inclusion levels significantly improved the ADC values for dry matter and protein, which was also associated with an increase in the micro-supplementation level. Thus, the result of the present study showed the ability of hybrid red tilapia to digest diets micro-supplemented with whole C. vulgaris at different inclusion levels.