Reduced water oxygen levels affect maximal feed intake, but not protein or energy utilization efficiency of rainbow trout (<i>Oncorhynchus mykiss</i>)

Glencross, Brett

doi:10.1111/j.1365-2095.2007.00562.x

Cited by 77 publications

(76 citation statements)

References 27 publications

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“…Among environmental factors, the water DO level is known to influence food intake and growth of fish [19], [20], [21], [22], [23], [24], [25], [26], as confirmed in the current study by the lower food intake in trout under hypoxia compared to normoxia. Reduced food intake under limited DO conditions (hypoxia) has been explained by a reduced metabolic scope of oxygen for aerobic activities and metabolism, including those related to food processing [25], [27]. Our data further show an effect of dietary amino acid composition on food intake under hypoxia.…”

Section: Discussionsupporting

confidence: 73%

Oxygen Consumption Constrains Food Intake in Fish Fed Diets Varying in Essential Amino Acid Composition

et al. 2013

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Compromisation of food intake when confronted with diets deficient in essential amino acids is a common response of fish and other animals, but the underlying physiological factors are poorly understood. We hypothesize that oxygen consumption of fish is a possible physiological factor constraining food intake. To verify, we assessed the food intake and oxygen consumption of rainbow trout fed to satiation with diets which differed in essential amino acid (methionine and lysine) compositions: a balanced vs. an imbalanced amino acid diet. Both diets were tested at two water oxygen levels: hypoxia vs. normoxia. Trout consumed 29% less food under hypoxia compared to normoxia (p<0.001). Under both hypoxia and normoxia trout significantly reduced food intake by 11% and 16% respectively when fed the imbalanced compared to the balanced amino acid diet. Oxygen consumption of the trout per unit body mass remained identical for both diet groups not only under hypoxia but also under normoxia (p>0.05). This difference in food intake between diets under normoxia together with the identical oxygen consumption supports the hypothesis that food intake in fish can be constrained by a set-point value of oxygen consumption, as seen here on a six-week time scale.

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Section: Discussionsupporting

confidence: 73%

Oxygen Consumption Constrains Food Intake in Fish Fed Diets Varying in Essential Amino Acid Composition

et al. 2013

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“…Using linear regression to determine the partial efficiency of utilisation of energy (or protein) is a method that has been demonstrated to have substantial merit in terms of defining the energetics of growth and food utilisation in fish [12], but, there is continuing debate over whether the relationship between energy/protein intake and energy/protein deposition is linear or curvilinear [6][7][8]. Apart from fish reared at 36˚C, our data was consistent with a linear approach.…”

Section: Effect Of Temperature On Energy Utilisationsupporting

confidence: 68%

Effect of High Water Temperatures on the Utilisation Efficiencies of Energy and Protein by Juvenile Barramundi, Lates calcarifer

Glencross¹,

Bermudes²

2010

Fish Aquac J

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This study was undertaken to define the effects of temperature on the energy and protein partial utilisation efficiencies of juvenile Barramundi. The experiment used a factorial design with four temperatures (25ºC, 29ºC, 32ºC, and 36ºC) and three ration levels (low, moderate, satiety) to examine the response of Barramundi to varying digestible energy (DE) and digestible protein (DP) intake. Energy and protein deposition with varying intakes at most temperatures were linear, though aberrations occurred at 36ºC relative to the other temperatures. The coefficients of DE utilisation were relatively consistent at 0.56 ± 0.02 (mean ± SEM) between 25ºC and 32ºC, though at 36ºC this declined to 0.42 ± 0.04. Similarly the maintenance DE demand for the fish was relatively constant across the range 25ºC to 32 ºC (~40 kJ DE/metabolic body weight (MBW)/d), but at 36ºC dramatically increased to around 110 kJ DE/MBW/d. The coefficients of DP utilisation were also relatively consistent at 0.51 ± 0.02 between 25ºC and 32ºC, though at 36ºC this declined to 0.28 ± 0.12. Similarly, the maintenance DP demand at 36ºC dramatically increased from around 0.5 g DP/PBW/d to 1.5 g DP/PBW/d. These results demonstrate that at high temperatures Barramundi protein demand and utilisation is significantly compromised and this affects their ability to efficiently convert dietary protein to tissue growth.Keywords: Asian seabass; heat; temperature; stress; energetics; bioenergetics. IntroductionThe production of Barramundi (Lates calcarifer), also known as Asian seabass, in Australia occurs in water temperatures ranging from 18ºC to 36ºC [1]. Growth rates of Barramundi are optimal at around 30ºC -32ºC. Above this temperature, the growth rate plateaus before declining rapidly at temperatures exceeding 35ºC. Death occurs at around 38˚C -40ºC and larger fish appear to be more sensitive to higher temperatures than smaller fish [2]. Symptoms of thermal stress above 35ºC include slower growth rates, increased mortality, increased level of cataract formation, reduced rates of protein synthesis and increased levels of endogenous protein turnover [2-4]. Temperature stress has been shown to have a significant effect on the total maintenance energy and protein losses of Barramundi during periods of starvation and on the relationship between animal size and energy or protein demands for maintenance [5].One way to examine the implications of thermal stress on fish is to model its effects using a factorial bioenergetic approach [5,6]. Bioenergetic factorial models are an empirical model form that compartmentalizes the energy flows into either somatic (growth) or non-somatic (maintenance) components. In simplistic terms, the total energy demand model can be generally summarised as:Where M E and G E are parameters describing the efficiency of energy utilisation for maintenance and growth respectively and b is the metabolic weight exponent of the animal [5,6]. The total protein demand can also be estimated in a similar fashion, but with the energy terms sub...

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“…In this respect, satiety and hence dietary FI control have been associated with the degree of hepatic oxidative metabolism [54], [55] or the efficiency of oxygen use [56]. The comparison of the heat production values observed in the present study (133–149 kJ/kg 0.8 /d) with values calculated (i.e., H = MEI-RE) from literature for rainbow trout fed to satiation (e.g., 107 [57], 77–91 [58], 93–112 [59], 160 [60] and 103–112 [61] kJ/kg 0.8 /d), shows our values to be in the upper range, even after adjusting for the effect of temperature (positive curvilinear relationship between both variables, Figure 4). The present finding that heat production was similar irrespective of dietary composition in trout kept under normoxic condition, suggests that the DEI control in fish is a function of heat production.…”

Section: Discussionmentioning

confidence: 56%

Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout

et al. 2012

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The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2×2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (HP/E) vs. low (LP/E) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg−0.8 d−1) and growth (g kg−0.8 d−1) of trout were affected by the interaction between P/E ratio and NPE source of the diet (P<0.05). Regardless of dietary P/E ratio, the inclusion of carbohydrate compared to fat as main NPE source reduced DEI and growth of trout by ∼20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism.

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Reduced water oxygen levels affect maximal feed intake, but not protein or energy utilization efficiency of rainbow trout (Oncorhynchus mykiss)

Cited by 77 publications

References 27 publications

Oxygen Consumption Constrains Food Intake in Fish Fed Diets Varying in Essential Amino Acid Composition

Oxygen Consumption Constrains Food Intake in Fish Fed Diets Varying in Essential Amino Acid Composition

Effect of High Water Temperatures on the Utilisation Efficiencies of Energy and Protein by Juvenile Barramundi, Lates calcarifer

Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout

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