[show abstract][hide abstract] ABSTRACT: An experiment was conducted to determine the effects of supplemental dietary l-carnitine, chromium picolinate (Cr-Pic) and their combination on growth performance and serum total protein, cholesterol,
triglyceride and glucose of rainbow trout (Oncorhynchus mykiss). A total of 276 rainbow trout were randomly allocated to four groups. Fish (average initial body weight=151±1.69g)
were fed a basal diet without supplemental l-carnitine and chromium picolinate in the control group. The basal diet was supplemented with either 500mg/kg l-carnitine, 1.6mg/kg chromium picolinate or 500mg/kg l-carnitine plus 1.6mg/kg chromium picolinate for experimental groups1 (C), 2 (Cr-Pic) and 3 (C+Cr-Pic), respectively.
Fish were fed twice a day to apparent satiation for 58days. Weight gain, growth rate, feed consumption and feed conversion
ratio (feed/gain) were calculated for the whole period. At the end of the study, six fish were chosen randomly from each tank
to represent the experiment and frozen at −20°C for subsequent dorsal muscle analysis. The results showed no significant differences
in final body weight, weight gain or feed conversion ratio among groups. There were also no significant differences in serum
total protein, cholesterol, triglyceride or glucose concentrations among groups. Significantly higher lipid concentration
of dorsal muscle was observed in experimental groups1 and 3. In conclusion, supplemental dietary l-carnitine, chromium picolinate and their combination have no beneficial effects on improving growth performance and feed
conversion ratio in rainbow trout. However, dietary l-carnitine slightly increased lipid concentration in dorsal muscle of rainbow trout.
Aquaculture International 04/2012; 18(2):213-221. · 1.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: The effects of betaine supplementation on feed intake and growth performance in rainbow trout fed a plant-protein based diet were evaluated. Triplicate groups of rainbow trout (130 g) were fed the plant-protein basal diet, the basal diet with 1.5% betaine supplementation, or a fishmeal-based diet (control) for 80 days. Feed intake was significantly better (p<0.05) in fish fed the betaine-sup-plemented diet (161.2 g/fish) than in fish fed the basal diet (131.6 g/fish) and not significantly dif-ferent from fish fed the control (152.8 g/fish). Weight gain was significantly higher (p<0.05) in fish fed the betaine-supplemented diet (117.0%) than in fish fed the basal diet (95.9%). Results indi-cate that, in diets based on plant proteins that often have low palatability, betaine supplementation may improve feed acceptability and growth performance in rainbow trout. Introduction Feed is the single largest variable expense in intensively managed aquaculture systems. Fishmeal is a major ingredient in fish feeds because of its high protein quality and palata-bility. However, the increasing demand, high cost, and uncertain availability of fishmeal may necessitate its partial or total replace-ment with low-cost plant protein sources. Currently, commercial diets for carnivorous fish, such as rainbow trout, contain high levels of animal protein, most often fishmeal, but, due to their poor palatability, low levels of plant feedstuffs. Few studies have attempted complete replacement of fishmeal although it has been recommended when a palatability enhancer is used (Higgs et al., 1995; Kissil et al., 2000). Low-molecular-weight metabolites, including free amino acids, nucleotides and nucleosides, quaternary ammonium bases, and organic