Journals / Turkish Journal of Veterinary and Animal Sciences / 2001 / Cilt: 25 - Sayı: 5
Dietary carbohydrate level influencing feed intake, nutrient utilization and plasma glucose concentration in the rainbow trout, Oncorhynchus mykiss
- Pages
- 657–666
- DOI
- —
Abstract
A twelve-week nutrition trial was carried out to evaluate the efficacy of different carbohydrate levels on digestibility, feed intake, growth performance, carcass and muscle composition and plasma glucose level in the rainbow trout, Oncorhynchus mykiss. Three test diets were formulated using extruded wheat meal (15.3, 32.2 and 43.5%) as the carbohydrate source and fed rainbow trout (Initial Body Weight: 33.8$pm$ 0.46 g.). These were either restricted: LCR (Low Carbohydrate Restricted), MCR (Medium-Carbohydrate-Restricted) and HCR (High-Carbohydrate Restricted); or satiation: LCS (Low-Carbohydrate Satiation), MCS (Medium-Carbohydrate Satiation) and HCS (High-Carbohydrate Satiation) respectively. The aim of applying different feeding regimes was to quantify the protein sparing effect of carbohydrate and to determine the response of rainbow trout to different levels of carbohydrates. The results showed that protein, energy and carbohydrate digestibility was reduced with increasing dietary carbohydrate levels, whilst lipid digestibility was similar all the groups. There was a significant energy substitution from the carbohydrate source in the restricted groups. However, since the maximum feeding rate was reached in the restricted regimes (MCR and HCR), a similar sparing action of carbohydrate was observed in the satiation groups (MCS and HCS). All the groups displayed good growth performance, and exhibited growth that was LCS exhibited the highest (P 0.05). Transient hyperglycaemia was observed in trout fed a high carbohydrate diet. These results are discussed with respect to the protein sparing action of dietary carbohydrate in practical trout diets and the possible physiological effects of carbohydrates on feed intake regulation.
Özet
A twelve-week nutrition trial was carried out to evaluate the efficacy of different carbohydrate levels on digestibility, feed intake, growth performance, carcass and muscle composition and plasma glucose level in the rainbow trout, Oncorhynchus mykiss. Three test diets were formulated using extruded wheat meal (15.3, 32.2 and 43.5%) as the carbohydrate source and fed rainbow trout (Initial Body Weight: 33.8$pm$ 0.46 g.). These were either restricted: LCR (Low Carbohydrate Restricted), MCR (Medium-Carbohydrate-Restricted) and HCR (High-Carbohydrate Restricted); or satiation: LCS (Low-Carbohydrate Satiation), MCS (Medium-Carbohydrate Satiation) and HCS (High-Carbohydrate Satiation) respectively. The aim of applying different feeding regimes was to quantify the protein sparing effect of carbohydrate and to determine the response of rainbow trout to different levels of carbohydrates. The results showed that protein, energy and carbohydrate digestibility was reduced with increasing dietary carbohydrate levels, whilst lipid digestibility was similar all the groups. There was a significant energy substitution from the carbohydrate source in the restricted groups. However, since the maximum feeding rate was reached in the restricted regimes (MCR and HCR), a similar sparing action of carbohydrate was observed in the satiation groups (MCS and HCS). All the groups displayed good growth performance, and exhibited growth that was LCS exhibited the highest (P 0.05). Transient hyperglycaemia was observed in trout fed a high carbohydrate diet. These results are discussed with respect to the protein sparing action of dietary carbohydrate in practical trout diets and the possible physiological effects of carbohydrates on feed intake regulation.