Growth performance, oxidative stress indices and hepatic carbohydrate metabolic enzymes activities of juvenile Nile tilapia,Oreochromis niloticusL., in response to dietary starch to protein ratios

Abstract

The effect of various dietary starch to proteins ratios (STA/P) on growth performance, oxidative status and liver enzyme activities involved in intermediary metabolism in juvenile Nile tilapia was evaluated. Four isocaloric‐practical diets (12.73 MJ kg−1 digestible energy) with increasing STA/CP ratios were formulated. These were designated D0 (344 g crude protein (CP) and 163.5 g starch (STA) kg−1), D1 (310 g CP and 243 g STA kg−1), D2 (258 g CP and 322 g STA kg−1) and D3 (214 g CP and 401 g STA kg−1). Each diet was fed to triplicate groups of 60 fish (2.7 g) for 45 days. Compared with the control diet (D0), significantly (P < 0.05) depressed growth and feed efficiency were observed only in the groups fed on diet D3. The activities of hepatic enzymes involved in glycolysis and lipogenesis pathways were significantly enhanced in groups fed on diet D3 compared with other diets. A significant (P < 0.05) increase in catalase activity was detected only in groups fed on diet D3. Similarly, a significant (P < 0.05) enhancement in superoxyde dismutase, glutathione S‐transferases and glutathione peroxidise was observed in groups fed on diets D2 and D3 compared with other diets. Results demonstrate the ability of juvenile Nile tilapia to spare protein by dietary carbohydrate.

Growth and metabolic responses in Nile tilapia (Oreochromis niloticus) subjected to varied starch and protein levels of diets

“…This phenomenon was also observed as protein and/or carbohydrate intake increased, thus enhanced energy intake in our current study. Higher dietary carbohydrate levels have shown to stimulate activities of liver G6PDH and ME in Nile tilapia (Azaza et al 2015) and in this study. A positive relationship between liver G6PDH and/or ME activity and liver lipid deposition was noted in zebra sea bream (Diplodus cervinus; Coutinho et al 2015) with regard to dietary carbohydrate levels, which was further supported by the results of the current study.…”

“…The findings show a close relationship between plasma glucose level and wholebody lipid deposition with regard to dietary carbohydrate levels. As a consequence, glucose uptake is stimulated in the liver, an enhancement in hepatic (PK and GK) enzyme activities of glycolysis pathway (Caseras et al 2002), thus contributing an increase in liver glycogen content to maintain glucose homeostasis (Azaza et al 2015). This is further verified by the results of previous studies (Coutinho et al 2015).…”

Effect of Different Levels of Dietary Carbohydrate on Growth and Metabolic Enzyme Activity in Clarias batrachus (Linnaeus, 1758)

“…Thus, protein in diet mainly goes for metabolism rather than growth. But it has been already found in many studies that increasing digestible carbohydrate in the diet can be used to spare protein in diet (Hemre et al, 1989;Shiau et al, 1993;Azaza et al, 2013). Carbohydrates are easily available and inexpensive source in formulated feeds, which are efficiently utilised in several fish species (Gao et al, 2010).…”

Growth performance and nutrient utilization of Clarias gariepinus fed with different dietary levels of processed cassava leaves

“…Linamarin is cyanogenic glycosides (2-B-Dglucopyranosy 1oxy-isobutryo nitrite) found in leaves and tuberous roots of cassava, which release high toxic cyanide (HCN) during hydrolysis at the time of digestion (Presston, 2004;Aderemi et al, 2012;Akapo et al, 2014). Previous researchers have attempted to increase non-conventional plant and animal materials to replace conventional feed ingredients like maize and fish meal in fish feed ration (Falaye, 1988;Fagbenro, 1992;Olatunde, 1996;Baruah et al, 2003;Eyo and Ezechie, 2004;Azaza et al, 2015). According to Olurin et al (2006), maize is the major source of metabolizable energy in most compounded diets for Hetorebranchus x clarias hybrid species because it is readily available and digestible.…”