Effects Of Food Shortage Research Articles

Effect of food shortage and temperature on age 0+ salmonids: a contribution to predict the effects of climate change.

Brown trout Salmo trutta alevins were maintained at 8 and 11° C at three conditions over a 9day period from yolk sac exhaustion: fed ad libitum, starved or fed ad libitum after starvation. Whole-body gene expressions for proteins involved in energy metabolism and the two primary proteolytic pathways were assessed. This study is the first to show an over-expression of proteasome and autophagy-related genes in young stages of salmonids, particularly at 11° C.

Effect of food shortage on growth, energetic reserves mobilization, and water quality in juveniles of the redclaw crayfish, Cherax quadricarinatus, reared in groups

The aim of this study is to analyze the impact of food shortage on growth performance, by means of energetic reserves (proteins, glycogen and lipids) mobilization and hepatopancreas cells analysis in C. quadricarinatus juveniles maintained in groups, as well as the effect on culture water quality. Two experiments were performed, each of them with two feeding regimes during 45 days. The Control feeding regime, in which crayfish were fed daily (once a day) throughout the experimental period (DF), and the Cyclic feeding regime, in which juveniles were fed for 2 or 4 days (once a day) followed by 2 or 4 days of food deprivation (2F/2D and 4F/4D, respectively) in repeated cycles. Cyclic feeding influenced growth, biochemical composition from hepatopancreas and muscle, and water quality. Juveniles cyclically fed were unable to maintain a normal growth trajectory during 45 days. Apparent feed conversion ratio, apparent protein efficiency ratio, hepatosomatic index and relative pleon mass were similar in cyclic and daily fed animals and no structural damage was found in the hepatopancreas of juveniles subjected to cyclic feeding. The novelty of this study was the significant accumulation of proteins in pleonal muscle in both cyclic feeding regimes (approx. 18%) suggesting that the storage of this constitutive material during food shortage may be an adaptation for a compensatory growth when food becomes abundant again. The cyclic feeding regimes had a positive effect on water quality decreasing inorganic nitrogen concentration. This was due to the reduction in the amount of animal excretes and feces in the group that received approx. 50% less feed. Additionally, water pH was higher in cyclic feeding tanks, as a result of lower organic matter decomposition and consequent release of CO2. Accordingly, total ammonia in the water was significantly lower for the cyclic feeding regimes compared to their respective controls. This study suggests that the protocol of cyclic feeding could be applied at least 45 days in 1 g juveniles maintained in group conditions, without affecting the energetic reserves and hepatopancreas structure, emphasizing the high tolerance of this species to food restriction.

Food deprivation-dependent development and fecundity in Ophraella communa

Ophraella communa LeSage is native to North America and a biological control agent of the invasive weed Ambrosia artemisiifolia L. Since A. artemisiifolia plants grow old and die after September annually, O. communa suffers from food shortage. To understand the effect of food shortage or deprivation on population fitness of O. communa, the development and fecundity and hatchability of its progeny eggs were observed when larvae were offered A. artemisiifolia plants for either 3, 6, 12 or 24 hours daily. The results showed that larval food deprivation significantly influenced survival and developmental durations of larvae and pupae. Survival rates and developmental durations of larvae and pupae decreased and were prolonged significantly with decreasing time of larval daily food intake. Longevity and fecundity of adults shortened and decreased significantly with decreasing time of larval daily food intake. In addition, the hatch rates of progeny eggs decreased significantly with decreasing time of larval daily food intake. The present study suggests that food shortage is one of the most critical factors that suppresses O. communa populations. This can explain why field populations of the beetle decrease significantly with ageing and death of A. artemisiifolia plants after late September.

Seasonal food shortages and coping strategies adopted by rural households in Northern Ghana

A household survey was conducted in four villages in the Bolgatanga District of northern Ghana with the objective of identifying causes and effects of seasonal food shortages and coping strategies adopted by households to increase food availability. Data was collected using structured questionnaires from 200 households selected by the simple random technique and was analyzed using descriptive statistics, chi-square test and probit model estimation. Findings of the study showed that effects of food shortages on households included difficulties in maintaining wards in schools and inability to register under the National Health Insurance Scheme as indicated by about 80.0% of the respondents. The chi-square analysis showed that household size and farm size were related to farm per capita output at 5 and 10% significant levels respectively. The probit analysis showed that education, farm size, income from off-farm activities, income from rearing and sale of livestock/poultry and receipt of remittances were the significant variables that determined household food availability at 5% significant level. The study recommends that efforts at reducing food insecurity among rural households should focus on increasing rural household income by engaging in off-farm income generating activities, literacy promotion, food supply and credit provision. Key words: Bolgatanga municipality, coping strategies, food shortages, rural households.

The effects of food shortage during larval development on adult body size, body mass, physiology and developmental time in a tropical damselfly

Few studies have looked jointly at the effects of larval stressors on life history and physiology across metamorphosis, especially in tropical insects. Here we investigated how the variation of food availability during the larval stage of the tropical and territorial American rubyspot damselfly (Hetaerina americana) affects adult body size and body mass, and two physiological indicators of condition – phenoloxidase activity (an indicator of immune ability) and protein concentration. We also investigated whether larval developmental time is prolonged when food is scarce, an expected situation for tropical species whose larval time is less constrained, compared to temperate species. Second instar larvae were collected from their natural environments and reared in one of two diet regimes: (i) “rich” provided with five Artemiasalina prey every day, and (ii) “poor” provided with two A. salina prey every day. In order to compare how distinct our treatments were from natural conditions, a second set of last-instar larvae were also collected and allowed to emerge. Only body size and phenoloxidase increased in the rich regime, possibly to prioritize investment on sexually selected traits (which increase mating opportunities), and immune ability, given pathogen pressure. The sexes did not differ in body size in relation to food regimes but they did differ in body mass and protein concentration; this can be explained on the basis of the energetically demanding territorial activities by males (for the case of body mass), and female allocation to egg production (for the case of protein). Finally, animals delayed larval development when food was scarce, which is coherent for tropical environments. These findings provide key insights in the role of food availability in a tropical species.

Anticipatory maternal effects in two different clones of Daphnia magna in response to food shortage

The effects of food shortage on growth, fecundity, male production and offspring size and starvation tolerance in two different clones of Daphnia magna (Clone L and Clone P) were evaluated by disentangling the effects of resource depletion and crowding per se. Three experimental conditions were tested: high food - low daphnid density (the optimum), low food - low daphnid density and high food - high daphnid density. In the two first conditions, daphnids experienced the same population density but they had different food availability. In the two latter conditions, daphnids had the same per capita, low, food availability but they lived at different algae and daphnid densities. Moreover, the response of crowded females to recovery at high food availability and low population density was evaluated. Low food availability reduced growth and fecundity of both clones and increased male production only in the Clone L. Crowding per se did not affect growth but reduced fecundity. In both clones, low food availability due to low algae density enhanced investment in offspring size and resistance to starvation. In response to food shortage either due to low algae density and to crowding, Clone P increased the investment in offspring size and starvation tolerance but reduced fecundity to a lesser extent than Clone L and did not produce males. Clone L, in response to food shortage due to crowding at high algae density, increased development time, produced more males, as at low algae density, but halved fecundity producing offspring that were not starvationtolerant. These results might reflect differences in anticipatory maternal effects between clones and suggest that neonate quality varies according to either, the environment the mother experienced and the competitive environment the neonates will cope due to their mother life strategy.

Spatial, temporal and competition effects on size and weight of caddisflies (Insecta, Trichoptera) in emergence traps

Size, weight and abundance of eleven species of caddisfly collected in four emergence traps from 1983-1991 at the Breitenbach (Germany) were analyzed for spatial and temporal patterns. Scrapers were abundant and small, shredders rare but large, predators were in between. Individual weights of most species increased downstream. No weight change along the stream was detected in A. fimbriata, T. rostocki, P. conspersa and R. fasciata. At low discharge, specimen numbers of A. fimbriata and C. villosa decreased, but it increased in P. conspersa. No correlation between discharge and any weight measure occurred. Intra- and interspecific competition was detected only between the scrapers A. fuscipes, A. fimbriata and D. annulatus, with negative effects on size and weight of other species and of competitors. Similar findings in the shredder C. villosa were effects of site specific temperature patterns, not of direct competition. It was evident that dependencies or interactions discovered at individual sites generally did not occur at all sites simultaneously. Inter- and intraspecific competition for a limited food source was detected only in scrapers during periods of low flow. No effects of food shortage was discovered in shredders or predators. Thus, based on the individual and population success of caddisflies, it is argued that the stream community in the Breitenbach was mainly driven by physical forces, temperature and discharge. Only under particular spatial and temporal conditions competition effects do become evident.

Effect of food shortage and temperature on oxygen consumption in the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Abstract. Temperature and food availability are limiting factors for the establishment of tropical insects in temperate countries. In the alien pest beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), starvation and temperature have a significant impact on metabolic rate with oxygen consumption ranging from 0.5 µmol/g fresh mass (FM)/h at 12 °C to 3.4 µmol/g FM/h at 24 °C. At 12 °C, oxygen consumption decreased continuously during an entire period of starvation. However, at 16, 20 and 24 °C, beetles display a marked hyperactivity that leads to an increase in the oxygen consumption level during the first week of starvation, followed by a steep decrease until the end of the starvation period. Oxygen consumption either does not decline in fed beetles (observed at higher temperatures) or declines at a much shallower rate than in starved beetles (observed at cooler temperatures). During the first week of refeeding, Oxygen consumption rose steeply at 16, 20 and 24 °C before levelling off to the initial value (t0). At 12 °C, no compensation process was observed during recovery. This study reveals that an important threshold in the biology of A. diaperinus lies between 12 and 16 °C, leading to the onset of reduced locomotor activity and the promotion of survival to the detriment of reproduction. This ‘sit and wait’ behaviour is proposed as an adaptive strategy (i.e. inactivity and lower oxygen consumption coupled with low energetic requirements and high recovery abilities). Such behaviour and the observed hyperactivity were rarely described in insects before the present study. Together, the previous and present results suggest that A. diaperinus populations are likely maintained in temperate regions by immigration from warmer situations.

Effect of food shortage on the physiology and competitive abilities of sand martin (Riparia riparia) nestlings.

We examined developmental and behavioural plasticity of sand martin (Riparia riparia) nestlings hand-reared under laboratory conditions. We created six broods of six 4-day-old nestlings and randomly assigned them to one of the two following feeding regimens, each lasting for 3 days: (1) all nestmates fed a similar, limited amount of food (FR nestlings). This simulated synchronous hatching under conditions of food restriction. (2) Half the brood were food-restricted (FR/AL nestlings), and half were fed ad libitum (AL nestlings), as in asynchronously hatched broods with differential food allocation. Under both regimens, food restriction resulted in a reduction in body mass, intestinal mass, pectoral muscle mass, fat reserves, body temperature and resting metabolic rate (RMR). However, it simultaneously triggered a significant increase in intestinal uptake rates of L-proline and locomotor activity, quantified as frequency of crawling into the artificial nest tunnel by individual nestlings. Locomotor activity and intestinal uptake rates of L-proline by FR nestlings were higher than those of FR/AL young, while body temperature and RMR of FR nestlings were lower. We conclude that food-restricted nestlings responded actively to food shortages by upregulating their gut function, reducing the energy costs of maintenance and increasing locomotor activity. These behavioural and physiological responses were strongest in broods of similar-sized FR nestlings, which can be interpreted as an escalation of sibling competition. Thus, developmental and behavioural plasticity may be an important factor in the evolution of sibling rivalry.

Effects of food shortage and oversupply on energy utilization, histology, and function of the gut in nestling song thrushes (Turdus philomelos).

We measured food intake, digestive efficiency, body mass increments, resting metabolic rate (RMR), carcass fat content, size and histological structure of the gut, and the rate of intestinal brush border uptake of l-proline in song thrush (Turdus philomelos) nestlings subjected to food shortage or food surplus under laboratory conditions. We assigned nestlings between 3 and 7 d of age to one of the following treatments: (1) food restriction, which resulted in a slowed growth at the rate found in undernourished, wild nestlings; (2) overfeeding, which totally suppressed begging; and (3) intermediate feeding. Threefold differences in energy consumption caused fivefold differences in body mass increments of the nestlings. Despite this, body mass-corrected RMR and intestinal mass were not affected by the feeding regime. The energy content of fecal output was highest in food-restricted birds, while their carcass fat content was lowest among treatment groups. Intestinal uptake rates of l-proline were low in the overfed and intermediate-fed young but significantly increased in the food-restricted birds, who attempted to maximize their rates of growth and development within the restrictive limits set by feeding regime. We noted a marked decrease of intestinal villi height in overfed birds as compared to intermediate-fed and food-restricted nestlings. We conclude that song thrush nestlings are characterized by a limited plasticity of their developmental program, which prohibits overfed nestlings from significantly up-regulating their gut function to accommodate increased food intake. This suggests that they already grew at a rate close to their physiological maximum. We suggest two interpretations: (1) under natural conditions, song thrush nestlings do not face frequent, unpredictable fluctuations in food abundance that could select for developmental plasticity, or (2) strong selection for uniform adult phenotypes prevents flexible developmental trajectories, which would result in a diversity of adult phenotypes.

Food Security in the Sudan

The Sudan, with an area of one million square miles has a population of 26 million people, an annual GNP growth rate of 1 percent, and an inflation rate of over 70 percent. The country is heterogeneous in many respects including climate, geography, history, languages, and people. Eighty-five percent of the labor force is in the agricultural sector and agriculture contributes 30 percent to GNP. Ninety percent of the exports are agricultural raw materials that include: cotton, livestock, sesame, groundnuts, and gum arabic. Despite these exports, the country faces an acute balance of payment deficits, large budget deficits, and government expenditures. Sudan's external debt rose from $ 3.8 billion in 1978 to $ 13.5 billion in 1990. The depth of poverty determines the impact of the famine. The effects of food shortages, and purchasing power collapse are not felt in higher income groups with good asset bases. The poor face long-term constraints in food production, access to education, health care, markets, credit, improved inputs, and information. Over half a million people have died between 1984 and 1990 due to starvation. The situation is worse in

Effects of food availability and ambient temperature on hibernation in the Japanese dormouse,Glirulus japonicus

The effects of food availability and ambient temperature (Ta) on hibernation in the Japanese dormouse,Glirulus japonicus, were examined. When the dormice were deprived of food under natural environmental conditions in midwinter, they showed typical hibernation patterns; in contrast, the animals given ad lib food did not show continuous long-term torpor. Furthermore, exposure to constant low temperature did not affect the torpor patterns in the animals receiving adequate food. These results suggest that food availability plays a decisive role in the onset and maintenance of hibernation in this species, and that low Ta does not have a great influence on the torpor patterns in animals with access to food. This differs from the previous study that emphasized the importance of Ta in the occurrence of torpor and discounted the effects of food shortage.

The Effects of Food Shortage on Human Reproduction

The first dramatic effect of food shortage is upon fertility. The authors attribute the marked decline in fertility in Dresden following the second world war to a sudden reduction in food supplies from the formerly occupied territories following the fall of the German armies. There were also epidemics of low birth weight, miscarriage, and congenital malformations. The epidemic of low birth weight in Leipzig immediately after the war is illustrated, with note made of the existence of similar epidemics in all European cities affected by food shortages. Epidemics of miscarriage contributed to the decline of fertility wherever there was a food shortage. The effects of food shortage upon hormone status, how food shortage increases the risk of neural tube defects and other congenital malformations, and the long-term consequences of poor maternal nutrition are considered.

Population Dynamics of Poikilotherm and Homeotherm Vertebrates: Effects of Food Shortage

We have investigated how the population dynamics of two types of vertebrates is influenced by food shortage. One type consists of animals which show indeterminate growth rate (cut the coat to the cloth) e.g. fish. The other type includes animals which show a determinate type of growth rate (require a minimum daily food supply to survive), e.g. mammals and birds. To this end we have developed a model which assumes that animals biomass is regulated by food biomass alone (i.e. no predation), while food biomass follows self-regulating dynamics. The model predicts stable biomass for the first type of animals and unstable, cyclic biomass for the other. The results help to explain why fish in a pond often develop a stable population of numerous, small individuals, while e.g. hares or moose on an island, shielded from predation, develop a fluctuating population

Can Hosts Escape From Their Parasitoids?

Apanteles popularis, a parasitoid of Tyria jacobaeae, does not regulate its host numbers, though the percentage attack may be very high. The effects of food shortage of the host on its parasite are discussed and suggestions are made why Apanteles does not regulate its host. This lack of a regulating influence is also mentioned in several other parasite-host studies in naturally evolved systems. A hypothesis on co-selection is formulated that might explain the difference in effect of parasites in naturally evolved systems and man-made systems, where biological control through imported parasites is often successful.

British Food Journal Volume 20 Issue 6 1918

At a meeting of the Section of Epidemiology and State Medicine of the Royal Society of Medicine on March 8th, Captain M. Greenwood, of the Lister Institute, and Miss Cecily M. Thompson reported the results of an epidemiological study of the food problem. In an introductory account of the present state of physiological knowledge it was pointed out that, although certain matters—such, for instance, as the precise significance of the specific dynamic energy of foodstuffs —were still obscure, “ the real difficulty of the subject is not so much uncertainty respecting the justice of the physiologists' conclusions as the quantitative application of principles themselves clearly established.” In the second section of the paper the problem of muscular efficiency was discussed, and it was shown that existing knowledge is insufficient for the formulation of general rules, that each class of work must be specially considered with particular reference to the external conditions under which it is carried out. In the third section of the paper the statistics of consumption were reviewed, and it was shown that in them the relation between energy used and surface was not so close as might be expected on general grounds ; the authors concluded that the necessary uncertainty attaching to such data explained the lack of close concordance. They then gave a minute analysis of some data due to Amar with reference to muscular work, which they showed were fully concordant with physiological expectation. Standard tables giving the probable energy need for workers of different weights and doing different amounts of work had been calculated. A table containing Lefèvre's results on the heat loss of a clothed man exposed to different temperatures and air velocities was also exhibited ; the importance of this aspect of the matter and the value of Hill's investigations upon rates of cooling in connexion with rationing were emphasized. In the concluding section of the paper the effects of food shortage were discussed, and it was pointed out that a majority of the recorded famine sicknesses were not pure hunger effects, shortage of fuel and antecedent or coincident epidemic disease being chiefly responsible. The siege of Paris in 1870, that of Kut‐el‐Amara in 1915, and the historical outbreak of disease at the Millbank penitentiary mentioned recently although not pure famine effects, approximated more nearly to such a condition than any others recorded. From a study of the sequence of events in these cases in relation with the energy value of the diets consumed, it appeared that in each case the onset of sickness was gradual, and that its form depended upon local epidemiological considerations. The authors held that there was no one disease which stood in a peculiarly close relation to inanition ; that there was a general and gradual lowering of resistance to all forms of infection.