Aquaculture: Management, Challenges and Developments

(Axel Boer) #1

76 Safina Musa, Christopher Mulanda Aura and Rodrick Kundu


Bars are mean SD of three replications; values within the same column without a
common superscript are significantly different (p < 0.05).


Figure 4. hepatosomatic index, viscerosomatic index, intraperitoneal fat and intestinal
length ratio in Oreochromis niloticus fed various diets. A = CP35CL8,100; B=
CP35CL8,70; C = CP35CL12,100; D = CP35CL12,70; E = CP25CL8,100; F =
CP25CL12,100; G = CP25CL8,70; H = CP35CL8,50; I = CP35CL12,50; J =
CP25CL12,70; K = CP25CL12,50.


From the results, it was clearly shown that feed intake was inversely
related to the dietary lipid level. When fish are fed on high lipid diets, the
excess lipid which they are unable to utilize as energy is stored as fat and this
fat accumulation when high can reduce feed intake which consequently affect
growth negatively due to lack of nutrients (Daniels and Robinson, 1986;
Babalola and Adebayo, 2007). The low growth rate observed in fish fed with
high lipid diets in the present study could be due to the high deposition of fat
in their viscera cavity which affected their protein intake and consequently
reduced the growth (Marais and Kissil, 1979; Ogata and Murai, 1991; Jobling
and Miglavs, 1993; Shearer et al., 1997; Wealtherup et al., 1997; Silverstein et
al., 1999). While it seems that most fishes utilize dietary lipid well (Cowey
and Sargent, 1979), at high dietary levels, lipids may reduce fish growth,

Free download pdf