Evaluation of the net energy value of glucose (cerelose) and maize starch in diets for rainbow trout (Salmo gairdneri)

Abstract

1. Quadruplicate groups of rainbow trout (Sulmo gairdneri) (mean body-weight 24.9 g) were reared on six dietary treatments (practical-type diets) in a modified paired-feeding experiment for 12 weeks at 15" to determine the net energy (NE) value of starch and glucose to rainbow trout.2. Three test diets were prepared to contain (g/kg): 0 supplemented carbohydrate (diet I), 250 maize starch (diet 2) and 250 glucose (diet 3) and were given ad lib. to the trout with the feeding rate of the glucose-and starchfed groups being monitored after each feeding. The remaining three treatments involved controlled feeding of the trout with diet I at 75 % of the feed intake of trout reared on diets 2 and 3, so as to provide the same levels of protein and lipids without carbohydrate, and with diet 2 at 100% of the feed intake of trout reared on diet 3.3. The difference in the final carcass energy of the ad lib.-fed group and the respective controlled-fed group divided by the amount of dietary glucose or starch energy consumed by the trout is the NE value for that carbohydrate.4. The determined NE value of glucose was 3.99 kJ/g and starch 2.17 kJ/g, which is 24.6 and 12.6% respectively of the gross energy values of these carbohydrates in rainbow trout. .The results indicate that digestible energy and calculated metabolizable energy values for carbohydrates in rainbow trout overestimate the utilizable energy content of the diet.6. The determined NE values for glucose and starch in the present study should be used with caution since various factors (such as the feeding rate determined in the present study) may affect the utilization of dietary carbohydrates in rainbow trout.

Studies on digestibility and digestive enzyme activities in Labeo rohita (Hamilton) juveniles: effect of microbial α-amylase supplementation in non-gelatinized or gelatinized corn-based diet at two protein levels

“…Feeding of G corn increased the HSI compared with that of the NG corn fed group, which is in agreement with the findings in rainbow trout (Cowey et al 1977;Hilton et al 1987) and southern catfish, Silurus meridionalis (Fu 2005). This may be well correlated with the highest liver glycogen content in G corn fed groups in the present study, which is in agreement with the results of Stone et al (2003a), who found a significantly increased HSI in G wheat fed groups compared with the NG wheat groups due to increased deposition of liver glycogen.…”

Regulation of metabolism by dietary carbohydrates in two lines of rainbow trout divergently selected for muscle fat content

“…Carnivorous fishes are generally considered to be poor utilisers of dietary carbohydrates (Wilson, 1994;Moon, 2001;Hemre et al, 2002). For example, the rainbow trout (Oncorhynchus mykiss) exhibits persistent hyperglycaemia following ingestion of digestible carbohydrates or injection of glucose (Bergot, 1979;Wilson, 1994;Moon, 2001), without any clear increase in the provision of net energy (Hilton et al, 1987). Various assumptions were put forth to explain this poor utilisation, out of which insulin deficiency, lack of insulin-dependent glucose transporters and lack of an inducible hepatic glucokinase were proved to be false (Mommsen and Plisetskaya, 1991;Panserat et al, 2000a;Planas et al, 2000); low potency of glucose as an insulin secretagogue compared with amino acids, relatively low number of insulin receptors, lack of inhibition of endogenous glucose production and poor hepatic lipogenesis from glucose were proved to be true (Mommsen and Plisetskaya, 1991;Hemre and Kahrs, 1997;Navarro et al, 1999;Panserat et al, 2000b;Enes et al, 2009); reduced peripheral utilisation of glucose and inhibition of insulin secretion by other hormones requires more elaboration (Moon, 2001).…”

Potential use of triticale in diets for rainbow trout: effects of dietary levels and incidence of cooking

“…One of the interesting features of this cereal for terrestrial animal feeds is its relatively high lysine content (Davies, 1989 (Edwards et al, 1977;Refstie and Austreng, 1981;Hilton et al, 1987 Refstie and Austreng (1981) Bergot (1979).…”

“…Il est bien établi qu'une augmentation de l'apport en énergie digestible (sous forme de lipides ou de glucides digestibles) permet d améliorer les performances zootechniques chez la truite arc-en-ciel. Nous avons réalisé des essais afin d'évaluer la possibilité d'incorporation du triticale (variété (Bergot, 1979;Pieper and Pfeffer, 1979;Spannhof and Plantikow, 1983; Kaushik and Oliva Teles, 1985;Hilton et al, 1987;). …”

“…Carbohydrates represent the major and common source of energy in diets of higher animals usually provided by the starch content of cereals which enable optimization of formulating costs (Hilton et al, 1987 (Bragg and Sharby, 1970;Fernandez and MacGinnis, 1974;Gerry, 1975;Bixler et al, 1986 (Choubert et al, 1982: cylindrical tanks of 60 1 capacity with a flow rate of 5 I/min). For (Thivend et al, 1972) using glucoamylase and glucose oxidase; chromic oxide in diet and faeces according to Bolin et al (1952).…”