Research Article
Edwin Pei Yong Chow, Kah He
Abstract
We tested the feasibility and effect of including dietary carotenoids of different forms, microemulsified (MY) and non-microemuslified (NMY), in diets for hybrid catfish (Clarias macrocephalus × Clarias gariepinus). The results showed that the abdominal skin and back muscle yellowness (b*) of fish fed with 0.7 kg/t MY was higher than the other treatments (1.0 kg.t NMY and control) (p<0.05) with a score of 8.30 and 16.33 respectively. This group also gave the highest total carotenoid deposited in the muscle of 88.27 mg/kg. Carotenoid addition to the control diet at 1.0 kg/t NMY and 0.7 kg/t MY dosage have no adverse effect on the growth, in fact they helped to improve the body weight gain by 82.98 g and 84.17 g (p<0.05) with an FCR improvement of 13 points and 16 points (p<0.05) respectively. There was no adverse effect on the immune system after feeding carotenoid to the catfish and enhancement was observed in certain immune response indices when compared to the control. The findings in the present study were very significant because it supported that microemulsified yellow carotenoids (with smaller particle size of ~0.25 μm) and when used at lower inclusion rate of 30% could achieve better overall performance when compared to the regular size carotenoids and control due to its enhanced bioavailability.