Supplementation of maca (Lepidium meyenii) tuber meal in diets improves growth rate and survival of rainbow trout Oncorhynchus mykiss (Walbaum) alevins and juveniles

2004 ◽  
Vol 35 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Kyeong-Jun Lee ◽  
Konrad Dabrowski ◽  
Jacques Rinchard ◽  
Carlos Gomez ◽  
Leszek Guz ◽  
...  
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Lepidium Meyenii ◽  
Rainbow Trout Oncorhynchus Mykiss

Individual variation and interrelationships between swimming performance, growth rate, and feeding in juvenile rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 55 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
T Ryan Gregory ◽  
Chris M Wood
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Plasma Cortisol ◽  
Positive Relationship ◽  
Swimming Performance ◽  
Individual Performance ◽  
Significant Positive Relationship ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Variation among individuals in specific growth rate (SGR), feeding, and two measures of swimming performance and their possible interrelationships were investigated in juvenile rainbow trout (Oncorhynchus mykiss) kept in groups on either satiation or half-satiation rations. Maximum sustainable velocity (Ucrit) was measured as an index of aerobic swimming performance and stamina (fatigue time in a fixed-velocity test at 6 body lengths ·s-1) as an index of anaerobic performance. Individual performance in both of these tests was found to be significantly repeatable. Trout fed on half-satiation ration exhibited significantly lower mean values of SGR and body size and higher levels of aggression-related fin damage, but no significant differences in stamina, relative or absolute Ucrit, glycogen content, or plasma cortisol. However, in these fish, there was a significant negative relationship between SGR and relative Ucrit, a significant positive relationship between SGR and stamina, and a significant positive relationship between SGR and total daily meal. None of these relationships were seen in fish fed to satiation. Plasma cortisol and tissue glycogen stores were not related to SGR. These results indicate that under the intensified competition of restricted ration, there are trade-offs between growth, feeding, and different types of swimming performance.

RNA/DNA ratios in white muscle as estimates of growth in rainbow trout held at different temperatures

1990 ◽  
Vol 68 (7) ◽  
pp. 1494-1498 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Specific Growth ◽  
Fish Size ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Different Temperatures ◽  
Specific Growth Rates ◽  
Rna And Dna

The concentrations of RNA, DNA, and protein in white muscle from 240 uniquely tagged rainbow trout (Oncorhynchus mykiss) held at three temperatures (5, 8 (control), and 11 °C) were measured. Both RNA and RNA/DNA ratios were better predictors of recent length- and weight-specific growth rates than they were of absolute fish size. Furthermore, RNA concentrations were better predictors of growth than RNA/DNA ratios. The strength of the regression between either RNA/DNA ratio or RNA and growth rate did not differ consistently among temperatures. Fish reared at warmer temperatures had lower concentrations of RNA for both a given growth rate and a given DNA concentration compared with cold-reared trout. Warm-reared fish also had lower concentrations of DNA and higher protein/DNA ratios than cold-reared trout when fish size was standardized. The concomitant decrease in both RNA and DNA concentrations resulted in marginally lower RNA/DNA ratios in warm-reared fish.

Hybridization with Domesticated Rainbow Trout (Oncorhynchus mykiss) Reduces Seasonal Variation in Growth of Steelhead Trout (O. mykiss)

1993 ◽  
Vol 50 (3) ◽  
pp. 480-487 ◽  
Author(s):  
Jörgen I. Johnsson ◽  
W. Craig Clarke ◽  
Ruth E. Withler
Keyword(s):  
Growth Rate ◽  
Seasonal Variation ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Natural Waters ◽  
Salt Water ◽  
Feeding Activity ◽  
Steelhead Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Winter Conditions

We tested the hypothesis that hybridization with domesticated rainbow trout (Oncorhynchus mykiss) reduces the seasonal variation in growth in both fresh and salt water in anadromous steelhead trout (O. mykiss). The seasonal variation in freshwater growth was more pronounced in the steelhead trout than in the hybrid and domesticated trout. Consequently, differences in growth rate among groups were considerably higher during winter than in fall or spring. We suggest that high feeding activity during unfavourable winter conditions in natural waters is maladaptive, but is not selected against in protected hatchery environments with a continuous food supply. This may lead to genetic divergence in feeding physiology and/or behaviour between steelhead trout and domesticated rainbow trout. Growth rates in experimental groups transferred to seawater in December relative to groups transferred in April were faster in rainbow and hybrid trout than in steelhead trout. The results support the hypothesis that seasonal variation in seawater growth in steelhead trout is reduced by crossing with domesticated rainbow trout.

Physiology and performance of wild and domestic strains of diploid and triploid rainbow trout (Oncorhynchus mykiss) in response to environmental challenges

2015 ◽  
Vol 72 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Mark A. Scott ◽  
Rashpal S. Dhillon ◽  
Patricia M. Schulte ◽  
Jeffrey G. Richards
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Speed ◽  
Hypoxia Tolerance ◽  
Consistent Difference ◽  
Critical Swimming Speed ◽  
Environmental Challenges ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Wild Strains

To determine the factors that may contribute to the poor survival of triploid (3n) rainbow trout (Oncorhynchus mykiss) in lake stocking programs, we compared the physiology and responses to environmental challenges of four wild strains and one domestic strain of diploid (2n) and 3n juvenile rainbow trout. Over four successive years, wild trout were caught from nature, spawned, and progeny were reared in a hatchery along with hatchery-bred domestic trout. Offspring of each strain were raised for up to 12 months as both 2n and 3n, and growth rate, critical swimming speed, routine oxygen consumption rate, critical oxygen tensions, thermal tolerance, and hypoxia tolerance were assessed in a laboratory setting. Cohorts of the 2008, 2009, and 2010 wild strains were also stocked into two experimental lakes and recaptured as adults using traps and fyke nets in 2011 for laboratory analysis. In the juvenile trout, the only measure of performance to show a consistent difference between 2n and 3n individuals across all strains was hypoxia tolerance, where 3n trout had a shorter time to loss of equilibrium (LOE) at 16 Torr than their 2n counterparts, but this effect was not seen in adult, lake-reared trout. Strain had a significant effect on specific growth rate, critical swimming speed (Ucrit), and time to LOE in hypoxia, although the effects of strain on these variables was not consistent from year to year. Overall, this study suggests that poorer hypoxia tolerance in 3n trout compared with 2n trout may be a contributing factor to the higher lake stocking mortalities in 3n trout.

scholarly journals ECONOMIC EVALUATION OF RAINBOW TROUT (Oncorhynchus mykiss) FARMING FED WITH DIFFERENT COMPOSITION FEED

2016 ◽  
Vol 8 (2) ◽  
pp. 55-65
Author(s):  
Milorad Mirilović ◽  
Vlado Teodorović ◽  
Radmila Marković ◽  
Aleksandra Aleksić-Agelidis ◽  
Branislav Vejnović ◽  
...  
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Economic Evaluation ◽  
Oncorhynchus Mykiss ◽  
Economic Performance ◽  
Feed Quality ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pelleted Feed ◽  
Combined Feed ◽  
Experimental Group

This paper evaluates the eff ects of two diff erent feeds on production results and economic performance in the rainbow trout (Oncorhynchus mykiss) farming. The first group (O-1) was fed with a standard complete pelleted feed, and the second group (O-2) was fed with combined feed consisting of 75 % pellets and 25 % of sardines. Better results were obtained with the O-2 group, while the O-1 group achieved results characteristic for local farming conditions and feed quality. Experimental group O-2 had signifi cantly higher (p<0,01) growth rate when compared to group O-1. Considering current feed and fi nal product (fi sh) prices in the market, better results in terms of cost-eff ectiveness were obtained (E>0,00) in O-2 group of trout fed with the combined meal.

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