EFFECT OF DIETARY PREBIOTIC MANNAN OLIGOSACCHARIDE ON GROWTH AND HEALTH STATUS OF ASIAN CATFISH (Clarias batrachus) JUVENILES

Abstract

This study was directed to estimate the effects of mannan oligosaccharide (MOS) dietary supplementation on growth, proximate composition and haematological parameters in Asian catfish (Clarias batrachus). Triplicate groups of juveniles Asian catfish (initial weight 21.23 ± 1.01 g) were fed twice per day at 3 % of body weight for 12 weeks, with 0 (control), 0.2, 0.4 or 0.6% MOS diets. Water temperature, pH, dissolved oxygen, NH4 +and NH3 were checked in every two weeks, which were ranged between 17.66-18.42°C, 7.06- 7.22, 5.06-6.13 mg L-1, 0.49-0.61 mg L-1 and 0.34-0.48 mg L-1, respectively. Compared to control (0.57±0.04), those fed 0.4% (0.82±0.05) or 0.6% (0.77±0.04) MOS had significantly higher (P< 0.05) specific growth rates. Feed conversion ratio and protein efficiency ratio significantly enhanced (P< 0.05) in fish fed 0.4% MOS diet compared to control. The survival rate of the control fed group exposed significantly the lowest (P <0.05) when compared with the treated fish fed with MOS supplemented diets. Significantly lower (P <0.05) HSI was noted when the fish fed 0.2% and 0.4% MOS diets compared to those fish fed control, but it did not differ from those fish fed with 0.6% MOS diet. Similarly, IPF was significantly lowest (P <0.05) in those fish which fed 0.4% diets over the control the group. Whole body proximate composition of Asian catfish exposed that significantly highest (P < 0.05) protein content were observed in fish fed with 0.4% MOS supplemented diet, whereas the ash content was significantly highest (P < 0.05) in fish group fed with 0.6% MOS. Dietary inclusion of MOS did not show any significant influence on the majority of the haematological parameters of Asian catfish. But it presented a significant positive influence on some of the most important parameters, namely ESR, PCV and WBC. Significantly reduced (P < 0.05) ESR and increased PCV (%) were noted when the fish fed with higher concentration of MOS (0.4% and 0.6% MOS) diets compared to control and lowest concentration of MOS such as 0.2%. xii Feeding the fish with MOS supplemented diets showed significant influence (P < 0.05) on the WBC compared with the control diet. Thus, 0.4% MOS is sufficient to increase growth, feed utilization and haematological parameters in juvenile Asian catfish.