Satiation Ration Research Articles

Dietary regulation of activities and mRNA levels of trypsin and amylase in sea bass (Dicentrarchus labrax) larvae

Specific activities and mRNA levels of trypsin and amylase were studied in sea bass larvae. From day 20 to day 40, Dicentrarchus labrax were fed two rations of one day old Artemia: satiation (LP) and one-eighth of the satiation ration (LP/8) or two isoenergetic compound diets that varied in protein (30 and 60%) and carbohydrate (37 and 7%) content (FP30 and FP60 respectively). Trypsin mRNA levels and specific activities were mainly influenced by the nature of dietary protein and the Artemia ration. By using fish meal as protein source, dietary protein concentration did not affect either mRNA level nor specific activity of trypsin. These results suggested that the trypsin synthesis was not affected at a transcriptional level by the protein ration, i.e., Artemia ration. Decrease in amylase mRNA observed from day 29 in the four dietary groups suggested that this decrease in amylase expression is genetically programmed during sea bass larvae development. Nevertheless, the composition and the quantity of the diet influenced the amylase specific activities revealing primarily translational regulation of amylase. This study shows for the first time that the molecular mechanisms which control the dietary adaptation of trypsin and amylase are independently regulated, age-dependent and influenced by the composition and the quantity of the diet.

Effect of Body Size and Ration on Specific Dynamic Action in the Antarctic Plunderfish,Harpagifer antarcticusNybelin 1947

The feeding energetics of the Antarctic spiny plunderfish (Harpagifer antarcticus) were examined with respect to the effect of both ration size and animal size. Fish of different sizes were fed single meals at one of two ration levels (2.5% wet body mass and satiation) to determine the maximum aerobic scope that could be elicited by the specific dynamic action. The excretion rates of ammonia, urea, and fluorescamine-positive substances were also monitored. Neither fish size nor ration had any effect on the factorial aerobic scope of feeding, which suggests that cellular metabolic processes associated with feeding were satiated by relatively small meals. The factorial scope in ammonia excretion was affected by both ration and fish size, indicating that respiration and excretion respond to a meal independently. The duration of the specific dynamic action response (240-390 h) increased with fish size but not ration, whereas both the time to reach the peak oxygen consumption and the duration of the ammonia response increased with ration but not fish size. The percentage of the ingested energy that was expended following feeding (the specific dynamic action coefficient) was high at low rations (approximately 56%) but lower (roughly 10%) at satiation rations. This is because the absolute energetic cost of processing a meal was largely independent of meal size. The change in O:N ratios after feeding was very ration-dependent; at low rations, O:N ratios increased, whereas at satiation rations, the O:N ratios decreased.

Sea bass ( Dicentrarchus labrax) larvae fed different Artemia rations: growth, pancreas enzymatic response and development of digestive functions

Sea bass larvae were fed different rations of 1-day-old Artemia from day 16 until day 38: satiation (R1), one-half ( R 1 2 ), one-quarter ( R 1 4 ) and one-eighth ( R 1 8 ) of the satiation ration. Survival was not significantly different among the four groups; the higher the ration, the greater the growth. In the pancreatic segment, trypsin activity was directly related to food ration, whereas amylase activity was inversely proportional. Trypsin secretion increased with age earlier in R1 and R 1 2 groups than in the two highly restricted groups. R 1 8 maintained a high level of leucine-alanine peptidase (an intestinal cytosolic peptidase). The preservation at day 38 of high amylase and leucine-alanine peptidase levels, in highly restricted larvae, indicates a delay in the development of the adult mode of digestion.

Supplemental Feeding of Tilapia in Fertilized Ponds

AbstractThe addition of feed to fertilized fish ponds was evaluated by adding feed alone, feed plus fertilizer, or fertilizer alone to nine ponds stocked with Nile tilapia Oreochromis niloticus. Two experiments were conducted. The first had 500 fish per 250 m2 pond in 3 treatments: ad‐libitum feeding; fertilizer only; or fertilizer and ad‐libitum feeding. The second experiment had 5 treatments with 750 fish per pond ad‐libitum feed only; fertilizer only; or 0.25, 0.50, and 0.75 satiation ration plus fertilizer. Ponds in Thailand were maintained for 155–162 d, during which chemical and physical properties were monitored. In experiment 1 tilapia growth was highest in feed only ponds, and lowest in fertilizer only ponds. Net yield did not differ significantly among treatments, due to variation in survival. In experiment 2, tilapia growth was lowest in fertilizer only ponds, intermediate in 0.25 ration ponds, and highest in 0.50, 0.75, and ad‐libitum ponds. The latter treatments were not significantly different. Multiple regressions for each experiment indicated only 47–87% of the variance in growth was explained by feed and fertilizer input, while 52–89% of the variance in yield was explained by those factors. For both experiments combined, 90.3% of the variance in growth was explained by feed input, fertilizer input, alkalinity, and total inorganic nitrogen concentration. For yield, R2 was 0.888 and the regression included feed input, pH, and number of low dissolved oxygen events. Experiment 1 appeared to approach carrying capacity near the end, while no reduction in growth occurred in experiment 2 at higher fish density and biomass. Reductions in growth in experiment 1 were not correlated with declining water quality late in the grow out. Combinations of feed and fertilizer were most efficient in growing tilapia to large size (500 g) compared to complete feeding or fertilizing alone.

Neuropeptide Y attenuates satiety: evidence from a detailed analysis patterns ingestion

Centrally injected neuropeptide Y (NPY) is a potent stimulant of ingestive behavior capable of augmenting both food and fluid intake in fully satiated animals. To gain further insight into NPY's mechanism of action, we recorded patterns of licking behavior in rats drinking sweetened condensed milk solutions immediately after lateral ventricular injection of NPY (10 μg) or vehicle. In a separate study, we examined licking patterns after 23 h food deprivation (FD) that produced approximately the same total intake as NPY. Consistent with previous reports, we found NPY stimulated intake by increasing total ingestion time and total volume consumed during a 1-h test. Although NPY the number of bouts of licking and shortened pauses between bouts, it also decreased mean bout size, duration and within-bout lick rat (local rate). It had no significant effect on start latency or lick efficiency (licks/ml). Further analyses revealed that NPY attenuated satiety (reduced slope of lick-rate functions with session time) but had no significant effect on the beginning lick rate, a measure related to orosensory excitation. In contrast to NPY, FD increased both the beginning lick rate and individual bout size without changing either the mean number of bouts or the pause between bouts. In general, NPY stimulated an intermittent pattern of licking and delayed satiation whereas FD increased the initial rate of licking and the size of individual bouts without changing the basic licking pattern. The increase in initial lick rate suggests that FD, unlike NPY, enhances orosensory stimulation. These data compliment previous results showing that NPY increases the motivation to eat. In particular, the present data suggest that NPY also promotes ingestion by producing a distinctive pattern of ingestion and slowing the rate of satiation.

Effect of Dietary Protein Content on Growth of Juvenile Mussels, Mytilus trossulus (Gould 1850).

Juvenile mussels, Mytilus trossulus, were fed for 3 weeks on either low-protein (LP) algae, high-protein (HP) algae, or a combination of LP algae and protein microcapsules (PM). Growth rates of mussels fed a satiation ration of 27.5% body weight (bw; ash-free dry weight of algae/ash-free dry tissue weight of mussels) per day of LP algae (28% protein percent weight per weight) were significantly (P < 0.05) lower than growth rates of mussels fed a satiation ration (27.5% bw d-1) of HP algae (43% protein weight per weight). However, growth rates of mussels fed LP algae (27.5% bw d-1) supplemented with one of three different rations (6, 12 and 18% bw d-1) of PM increased proportionally to PM ration size. Mussels fed a diet containing LP algae with the highest level of PM supplementation grew at rates that were not significantly different from those of mussels fed a diet of HP algae alone. Growth rates of mussels fed LP algae alone were not improved if the ration of LP algae was increased (34.1% bw d-1), indicating that the positive growth response of mussels fed PM supplements was due to an increase in dietary protein content and not simply due to an overall increase in food (energy) availability. In addition, mussels fed LP algae had O/N ratios > 18, indicating that they were conserving dietary protein from catabolism; whereas mussels fed protein-rich diets had O/N ratios <10, indicating that they were catabolizing dietary protein. These results suggest that dietary protein contents below 40% w/w and dietary C/N ratios above 10 can qualitatively limit growth rates of juvenile M. trossulus.

Influence of Food Density on the Satiation Ration of Macrobrachium rosenbergii Larvae

Influence of Food Density on the Satiation Ration of <I>Macrobrachium rosenbergii</I> Larvae

Influence of Food Size on the Satiation Ration of Macrobrachium rosenbergii Larvae

Influence of Food Size on the Satiation Ration of <I>Macrobrachium rosenbergii</I> Larvae

Plasma insulin, glucagon, glucagon-like peptide and glucose levels in response to feeding, starvation and life long restricted feed ration in salmonids

Plasma insulin, glucagon, glucagon-like peptide (GLP) and glucose were measured in samples taken from rainbow trout,Oncorhynchus mykiss. (1.5 years of age) before feeding and at selected times up to 9 days after feeding. The feed contained 21.7% carbohydrate (65% digestibe) in the dry matter. The fish responded to feeding with an elevated plasma insulin level (p<0.005) 0.5 h post-feeding, which may account for the unchanged plasma glucose levels. Twentyfour hours after feeding, plasma insulin level had returned to prefeeding levels, while 4-9 days after feeding, a significant reduction compared to pre-feeding levels was observed (p<0.001). During this period plasma glucose levels remained unchanged. The corresponding plasma glucagon or GLP levels showed no significant elevation in response to starvation, the plasma GLP concentration was even significantly reduced on days 4-9 post-feeding (p<0.01-0.001).Atlantic salmon,Salmo salar, (3.5 years of age) fed a calculated satiation ration (RL=100) throughout their lifetime had, in addition to a higher body weight, significantly higher plasma insulin (p<0.005) glucagon (p<0.0001) and GLP levels (p<0.0001) than fish fed half the satiation ration. The plasma glucose levels were, however, not significant different between the groups.

Effect of Feeding Rate on Growth and Feed Conversion of Florida Red Tilapia Reared in Floating Marine Cages

AbstractAn experiment was conducted to investigate growth, survival and feed conversion of Florida red tilapia reared in floating cages in seawater under different feeding regimens. Twenty‐four cages (1 m3) were anchored in a sea pass on Great Exuma, Bahamas, and each was stocked with 300 juvenile, monosex males (10 g mean weight). Growth was monitored every 14 days for 84 days. Fish were fed daily a floating pelletized diet (32% protein) at 4 programed rates representing 50, 70, 90, and 110% of the estimated satiation rate, ad libitum, and by demand feeders, with each treatment comprised of 4 replicate cages.Final mean weight was significantly lower for the 50% treatment (94.1 g) than for all other treatments (range = 121.8–155.7 g). Final mean biomass per cage ranged from 24.2 to 39.4 kg/m3, and survival ranged from 98.2 to 99.8%.Mean specific growth rate was significantly lower under the 50% programed feeding treatment (2.42%/day) than for all other treatments (range = 3.15–3.56%/day) while feed conversion ratios (dry weight/wet weight) were significantly lower under the 50% (1.57) and 70% (1.68) programed feeding treatments than under all other treatments (range = 1.98–2.26). Thus, maximum growth was achieved at feeding rates near satiation while feed conversion was improved at lower feeding rates. Under demand feeding, growth and feed conversion were not significantly different than those of the ad libitum, 100%, and 90% treatments.

Protein, lipid, water and caloric contents of immature rainbow trout, Salmo gairdneri Richardson, growing at different rates

Protein, lipid, water and caloric contents of immature rainbow trout, relative to size of whole fish, growing at different rates were examined by use of allometric analysis (y = axb, Huxley, 1932). Fish grew at different rates as a result of differences in ration size (satiation, or 4–5% of dry body weight), temperature (7 and 12°C) and bGH (bovine growth hormone) administration. In fingerlings, protein, lipid and caloric contents tended to increase (v. body weight) as a percentage of body composition, whereas above fingerling size, protein decreased while lipid and caloric contents still increased. These trends occurred regardless of growth rate differences. The correlations between protein, lipid, caloric contents and body weight were high so reliable estimates of body components can be made from body weight for all experimental treatments. At satiation rations (7 and 12°C), there were no significant differences in protein content, but lipid and caloric contents were significantly higher in control fish. At low rations, protein and caloric contents were lower than those at satiation rations and lipid was lower than in the control group. On a dry weight basis, in uninjected fish at 12°C, ration size did not influence the percentage composition (protein and lipid) but the low ration group had lower energy values per unit of body dry weight. At low temperature (7°C satiation), fish had lower lipid and higher protein content (dry weight basis) than their controls (12°C satiation), thereby resembling bGH injected fish at satiation rations. Values of caloric content estimated from protein and lipid values by use of standard conversion factors differed sufficiently from caloric values directly determined by bomb calorimetry to suggest that caloric values of lipids may change during growth. The increase in body caloric content during growth apparently results mainly from an increase in the percentage of lipid. The similarity of body composition between different growth rate groups implied a tendency for conservation of relative proportions of components such that body composition can be approximated from body weight. Equations were also given to describe the relationship between water content and body constituents, and the relationship between condition factor (K) and both the body dry weight and lipid content.

A novel reinforcement procedure for use in perceptual experiments with normal and language-impaired children.

A novel reinforcement procedure for use with young children with or without language impairments has been devised which adds intrinsic interest to otherwise tedious clinical or experimental sessions and has a low rate of satiation. The procedure involves the child "winning" colorful stickers to make a picture throughout testing sessions.

The Estimation of Daily Rates of Food Consumption for Fish

SUMMARY (1) Previous studies on rates of gastric evacuation and food consumption are briefly reviewed and criticized. The truly quantitative studies show that the evacuation rate is usually exponential and is related to water temperature by an exponential or power-law function. These relationships have been ignored in most of the previous methods used to estimate the daily food consumption for fish in the field. (2) Two new methods are proposed and both assume that the rate of gastric evacuation is exponential. The rate of food consumption is assumed to be constant within the interval between sampling in the first method, and to decrease with time in the second method which also requires an estimate of the satiation ration. Equations are developed for both methods. (3) In a series of experiments with brown trout and perch, the first method usually provided close estimates of the daily food consumption even when feeding was restricted to short periods at infrequent intervals of time. The first method was inadequate, and the second method more appropriate, for larger fish feeding close to the maximum or satiation level. (4) The new methods are compared with some of the equations of earlier workers and the latter are shown to have often made erroneous assumptions that produced underestimates of the daily food consumption.

An electronic apparatus to measure the retinal-neural fading phenomena.

Fading and regeneration of visual stimuli is a phenomenon which occurs under the condition of redundant visual stimulation in the human eye. By totally encompassing a subject's visual field with large sheets of colored cardboard, which provided an undifferentiated ground, it was found that the color spontaneously disappeared and reappeared. This evidence suggested that the cycle is a fundamental aspect of the visual process. The Retinal-Neural Fading Phenomena Device was developed using light-emitting diodes (LED) as the stimulus source. This allowed the quantitative measurement of the rate of fade and degree of satiation the eye undergoes under a redundant presentation equivalent to stabilized images. The rate and degree of satiation to redundant stimulation appears to correlate highly with a subject's reading efficiency. The data suggested that rapid and deep satiation was the favored outcome if one is to be free from reading or perceptual disorders. This leads to the speculation that rapid fade of afterimages of previously read symbols is required to prepare the visual system for new material. Conversely, the inability to suppress afterimages may be a physiological factor in the "dyslexic syndrome."

Attention and Manipulative Play in the One-Year-Old Child

FENSON, LARRY; SAPPER, VICTOR; and MINNER, DAN G. Attention and Manipulative Play in the One-Year-Old Child. CmHL DEvELOPMENTrr, 1974, 45, 757-764. This study examined the stability of visual fixation and habituation in 12-month-old babies and the relation between visual attentiveness and play behavor. Fixation time was stable within a given session to different stimuli and across a 3-week period to the same stimuli. Habituation rate was not stable across the 3-week period. For females, both fixation time and habituation rate predicted rate of satiation in play with a familiar toy and relative degree of preference for novel toys. Attentiveness and play were uncorrelated for males.

群れの中の個体の行動について-I

The present paper deals with the psychological influence of the fish number on the feeding behavior of a fish in shoal under rearing conditions. Surf-fish (Ditrema temmincki) used in this study is a coastal weak shoaling species and is devoid of a stomach. The author regarded the feeding rate (amount of food intake/body weight) as an index of the change in the pattern of the behavior. Accordingly, in the first place, the time required to reach satiation by an individual fish and the tendency of food intake by the surf-fish in the day time were examined. Subsequently, the relationships between fish number and feeding rate of an individual fish in shoal were examined. The results obtained are summarized as follows: 1) The change in the feeding rate of an individual fish within 60 minutes after 23 hours of food deprivation is shown in Fig. 1. At the beginning of the experiment, the rate registered a high value, and then decreased radically within 30 minutes. After that, it decreased gradually with the lapse of time. 2) Surf-fish showed the tendency to take food continuously after satiation (Fig. 2). 3) The feeding rate of an individual fish increased radically with increasing the number of companions in a rearing tank (Fig. 3). 4) On the contrary, in the experiment to seperate the members in a shoal consisting of 40 fish, the average feeding rate in shoal consisted of from 30 to 15 members which maintained the maximum value (14%), and decreased gradually. Under 15 individuals, the feeding rate fell in accompaniment with the decrease in the members in the shoal (Fig. 4). In view of the results described above, it may be concluded that the increase in the number of companions removes the factors that oppress the appetite of fish. In shoal, the psychological situation of an individual fish changes so as to give full scope to its physiological ability, and the fish becomes psychologically satisfied to attain a larger rate of satiation. However, the rate of satiation of fish in shoal does not always show a constant value, even if the physical and chemical conditions are at an optimum. This implies that in rearing conditions the fish changes its behaviour in accordance to its previous experiences.

魚の飽食量測定に関する一実験

魚の飽食量測定に関する一実験