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Dive into the research topics where Malcolm Jobling is active.

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Featured researches published by Malcolm Jobling.


Food intake in fish. | 2001

Food intake in fish.

D. F. Houlihan; Thierry Boujard; Malcolm Jobling

List of Contributors. Preface. Feed Composition and Analysis (Malcolm Jobling). Feed Types, Manufacture and Ingredients (Malcolm Jobling, Emidio Gomes and Jorges Dias). Techniques for Measuring Feed Intake (Malcolm Jobling, Denis Coves, Borge Damsgard, Henrik R. Kristiansen, Juha Koskela, Thuridur E. Petursdottir, Sunil Kadri and Olafur Gudmundsson). Experimental Design in Feeding Experiments (Kari Ruohonen, Juhani Kettunen and Jonathan King). Gustation and Feeding Behaviour (Charles F. Lamb). Environmental Factors and Feed Intake: Mechanisms and Interactions (Patrick Kestemont and Etienne Baras). Environmental Factors and Feed Intake: Rearing Systems (Marie--Laure Begout Anras, Marilyn Beauchaud, Jon--Erik Juell, Deniks Coves and Jean--Paul Lagardere). Feeding Rhythms (Juan Antonio Madrid, Thierry Boujard and F. Javier Sanchez--Vazquez). Feeding Anticipatory Activity (F. Javier Sanchez--Vazquez and Juan Antonio Madrid). Effects of Feeding Time on Feed Intake and Growth (Valerie Bolliet, Mezian Azzaydi and Thierry Boujard). Effects of Nutritional Factors and Feed Characteristics on Feed Intake (Manuel de la Higuera). Regulation of Food Intake by Neuropeptides and Hormones (Nuria de Pedro and Bjorn Thrandur Bjornsson). Physiological Effects of Feeding (Chris Carter, Dominic Houlihan, Anders Kiessling, Francoise Medale and Malcolm Jobling). Feeding Management (Anders Alanara, Sunil Kadri and Mihalis Paspatis). Nutrient Partitioning and the Influence of Feed Composition on Body Composition (Malcolm Jobling). Glossary of Terms. Index


Aquaculture | 1988

A review of the physiological and nutritional energetics of cod, Gadus morhua L., with particular reference to growth under farmed conditions

Malcolm Jobling

Abstract Environmental tolerances and preferences of cod are reviewed and attempts are made to predict optimum conditions for growth. Physiological energetics data are collated and equations are derived enabling the prediction of food intake and growth rates of cod under different environmental conditions. The findings of nutritional studies are reviewed and hypotheses relating the effects of dietary formulation and food type to digestive efficiency, nutrient storage and body composition are presented. The results are discussed in relation to practical problems associated with the farming of cod.


Aquaculture | 1993

Effects of stocking density on food intake, growth performance and oxygen consumption in Arctic charr (Salvelinus alpinus)

Even H. Jørgensen; Jørgen S. Christiansen; Malcolm Jobling

Abstract Food intake, growth rates, and rates of oxygen consumption were measured in Arctic charr (Salvelinus alpinus), stocked at low (15 kg·m−3), medium (60 kg·m−3) and high (120 kg·m−3) densities. Growth rates were similar for fish stocked at the medium and high densities, but were markedly depressed at the lowest stocking density. Differences in growth were probably the result of similar differences in food intake. Low levels of food intake were probably also the prime reason for the low oxygen consumption rates recorded in the groups of fish stocked at low density. Stocking density affected the behaviour of the fish, and schooling behaviour was observed in the groups subjected to the medium and high stocking density. No significant correlations were found between initial body size, food intake and growth rates in the groups of fish held at any stocking density. Consequently, social constraints due to the formation of dominance hierarchies may not have been the prime reason for the appetite and growth reduction seen in groups stocked at low density.


Archive | 1993

Bioenergetics: feed intake and energy partitioning

Malcolm Jobling

The foundation for the study of fish bioenergetics and growth was laid during the late 1940s and early 1950s (Winberg, 1956; Brown, 1957), and during the 1960s research into ecological, and fish, energetics was supported through the International Biological Programme (Gerking, 1967; Grodzinski et al.. 1975; Bagenal, 1978). The past three decades have seen a continued increase in research efforts devoted to the study of fish growth and bioenergetics. Interest has been generated both from fisheries management, and, not least, by the recent upsurge in the aquaculture industry. Several multi author books and reviews have appeared since the mid 1970s, and these give a good background into both the general principles of bioenergetics. and the methodology used (Gerking. 1978; Hoar et al.. 1979; Tytler and Calow, 1985; Weatherley and Gill. 1987; Schreck and Moyle, 1990; Wootton. 1990).


Aquaculture International | 1994

The compensatory growth response of the Atlantic cod: effects of nutritional history

Malcolm Jobling; O.H. Meløy; J. dos Santos; B. Christiansen

The effects of different combinations of nutritional background, feeding regimes and dietary compositions on growth responses of the Atlantic cod have been examined. Alternating short periods (1–3 weeks) of food deprivation with unlimited provision of food depressed growth below that of controls, but cod that were fed on alternate weeks (1:1) were larger than those that were exposed to 2 or 3 week periods of deprivation and feeding (2:2 or 3:3). Thus, periods of food deprivation of short duration were insufficient to induce any marked compensatory growth response. When cod were deprived of food for longer periods a compensatory growth response was observed. On receiving excess food supplies following 8 weeks of food deprivation the fish grew more rapidly than the controls and had completely recovered body weight within 12 weeks. The greatest compensatory growth response was shown by cod in poor condition (lowest condition factor), because at the end of an 18 week growth trial there were no differences in body weight between fish irrespective of their initial condition. Both sexes displayed a compensatory growth response.


Aquaculture | 1985

Physiological and social constraints on growth of fish with special reference to Arctic charr, Salvelinus alpinus L.

Malcolm Jobling

Jobling, M., 1985. Physiological and social constraints on growth of fish with special reference to Arctic charr, Salvelinus alpinus L. Aquaculture, 44: 83-90. Physiological studies of growth in animals predict that growth rates should decrease with increasing size, but when Arctic charr, Salvelinus alpinus, were reared together in large groups there was often a positive correlation between initial body size and the growth rate of an individual fish. This suggested that social interactions were important determinants of growth rates and, in the absence of the establishment of direct linear hierarchies, it is suggested that growth suppression is the result of short-term bouts of aggression associated with feeding periods leading to reduced food intake by certain fish. Evidence is presented to show that growth suppression can be reduced by increasing the frequency of feeding.


Aquaculture International | 1993

Feeding, growth and environmental requirements of Arctic charr: a review of aquaculture potential

Malcolm Jobling; Even H. Jrgensen; Arne M. Arnesen; Einar Ring

Interest in the cultivation of Arctic charr arose during the 1970s, and research into charr farming was instigated in the Nordic countries and in Canada. Most work has been conducted on fish from anadromous populations, although ‘land-locked’ freshwater populations of Arctic charr have also received attention. Research has also been carried out in the British Isles and in the alpine regions of central Europe, where land-locked populations of charr. Small-scale commercial farming is now carried out in several countries of northern Europe and North America, and charr are reared for restocking purposes in a number of countries.Growth of charr is rapid during the early freshwater rearing stages, and quite good rates of growth can be achieved at low water temperatures. Growth may be submaximal if charr are reared in systems designed for other salmonids, and problems may arise when charr are held at low stocking densities. Growth and food conversion can be improved by exposing the fish to water currents, forcing them to swim at moderate speeds. Growth in seawater has been reported as being highly variable, probably as a result of the use of inappropriate rearing techniques and owing to the seasonal changes in the hypo-osmoregulatory ability of the charr.Prospects for aquaculture development and areas requiring further research effort are briefly discussed.


Environmental Biology of Fishes | 1986

Mythical models of gastric emptying and implications for food consumption studies

Malcolm Jobling

SynopsisTwo of the most important factors governing gastric emptying are meal volume and food composition. These factors have also been demonstrated to influence the secretion of gastric acid, digestive enzymes and gut hormones in both fish and mammals. In mammals, feedback loops involving gastrointestinal hormones have been implicated in the control of gastric motility and enzyme secretion. These findings are briefly reviewed and it is demonstrated how the functioning of the feedback loops could lead to changes in gastric emptying patterns. A simulation exercise was carried out incorporating these physiological observations into the emptying model. The results predicted that an exponential function would best describe the emptying of small, easily digested low energy food particles from the stomach, but that a linear expression would give a better fit to the emptying data when food consisted of high energy large sized particles. These predictions were supported by results obtained in a number of experimental studies. These results are discussed in terms of selecting methods for the estimation of daily food consumption of fish species.


Aquaculture | 2003

Digestibility, growth and nutrient utilisation of Atlantic salmon parr (Salmo salar L.) in relation to temperature, feed fat content and oil source

Eldar Åsgard Bendiksen; Ole Kristian Berg; Malcolm Jobling; Arne M. Arnesen; K. Måsøval

Digestibility, growth and nutrient utilisation of Atlantic salmon parr (Salmo salar L.) in relation to temperature, feed fat content and oil source


Aquaculture | 1993

Patterns of growth and lipid deposition in cod (Gadus morhua L.) fed natural prey and fish-based feeds

Jorge Santos; Ivan C. Burkow; Malcolm Jobling

Abstract Groups of cod were fed two natural prey types, prawn and herring, and two herring-based wet diets, one with low and the other with high energy density. Cod fed upon whole herring and enriched-herring paste showed the highest growth rates but tended to store increasing amounts of lipid in the liver. Cod fed upon the leanest diet, prawn, showed, however, better efficiencies of energy and nutrient conversion. The effect of decreasing food particle size, by mincing the herring, was to slightly impair growth and to substantially lower the efficiency of food conversion. The fatty acid compositions of the body lipids tended to reflect dietary input. The major lipid class in the muscle was the phospholipid whereas the main lipid storage depot consisted of triacylglycerols in the liver. There were some indications that either 20:5 n −3 was chain elongated to 22:6 n −3, or was selective utilized. Dietary 22:1 appeared to have been used as an energy source by the cod, a predator that naturally feeds on prey such as herring which are rich in these fatty acids.

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Cg Carter

University of Tasmania

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Pierre U. Blier

Université du Québec à Rimouski

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Arne M. Arnesen

Norwegian College of Fishery Science

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H. K. Johnsen

Norwegian College of Fishery Science

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Juhani Pirhonen

University of Jyväskylä

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