Abstract
This research involved testing the replacement of
corn gluten protein concentrate in the diet of 1.5 g
Nile tilapia with biofuel algae-based or algae supplemented
with phosphorus diets. Experimental diets
were formulated to replace 50% of the gluten meal
protein in the control diet with biofuel algae protein
(Alga50) or Spirulina (Spirulina50) protein. In addition,
dicalcium phosphate (P) was added to the
Alga50 at a concentration of 3.8% or 7.74% to mitigate
aluminium (Al) toxicity and designated as
Alga50 + P, and Alga50 + PP respectively. After
9 weeks of the feeding experiment, fish fed diets supplemented
with P, Alga50 + P and Alga50 + PP differed
significantly (P < 0.05) with respect to the feed
conversion and protein deposition from the control.
The mineral composition of the fish body showed a
decrease in levels of Al and iron (Fe) due to the P supplements.
The mineral composition of the faeces indicated
that Al and Fe were excreted in the faeces and
were not accumulated in the fish body. The effect of
dicalcium P supplementation on the neutralization of
Al in the diet resulted in improved fish growth and
histological integrity of the gastrointestinal tract.