Short-term decoupling of otolith and somatic growth induced by food level changes in postlarval Baltic sprat, Sprattus sprattus

2005 ◽  
Vol 56 (5) ◽  
pp. 539 ◽  
Author(s):  
Hannes Baumann ◽  
Myron A. Peck ◽  
Jens-Peter Herrmann
Keyword(s):  
Somatic Growth ◽  
Field Studies ◽  
Food Level ◽  
Short Term ◽  
Weight Growth ◽  
Linear Relationships ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Second Period ◽  
Ad Libitum Feeding

We studied the effects of food level changes on otolith and somatic growth in postlarval Baltic sprat reared initially for a period of 11 days under zero, low, and ad libitum feeding conditions. During a subsequent 11 day period, feeding regimes were reversed in half of the low and ad libitum feeding treatments, and starved fish were re-fed ad libitum rations. Somatic growth rates under low and ad libitum food rations ranged between 0.15–0.22 mm day−1 and 0.48–0.63 mm day−1, respectively, and led to significant differences in length and weight between feeding regimes. Previously starved fish, however, grew only 0.25–0.28 mm day−1 under ad libitum conditions. During the first period, significant linear relationships were found for otolith v. length and v. weight growth across all treatments. After changing feeding regimes, increment widths failed to significantly predict somatic growth for 9 days, after which a significant relationship between otolith and somatic growth became re-established. Recent otolith growth was a good predictor of fish condition after the first, but not after the second period. The results suggest that perturbations in environmental conditions can temporarily decouple otolith from somatic growth in postlarval sprat, which needs to be considered in field studies.

scholarly journals Novel energy-saving strategies to multiple stressors in birds: the ultradian regulation of body temperature

2016 ◽  
Vol 283 (1839) ◽  
pp. 20161551 ◽  
Author(s):  
Glenn J. Tattersall ◽  
Damien Roussel ◽  
Yann Voituron ◽  
Loïc Teulier
Keyword(s):  
Body Temperature ◽  
Multiple Stressors ◽  
Energetic Cost ◽  
Short Term ◽  
Ad Libitum ◽  
Key Sites ◽  
Ad Libitum Feeding ◽  
Reduced Surface ◽  
Internal Body

This study aimed to examine thermoregulatory responses in birds facing two commonly experienced stressors, cold and fasting. Logging devices allowing long-term and precise access to internal body temperature were placed within the gizzards of ducklings acclimated to cold (CA) (5°C) or thermoneutrality (TN) (25°C). The animals were then examined under three equal 4-day periods: ad libitum feeding, fasting and re-feeding. Through the analysis of daily as well as short-term, or ultradian, variations of body temperature, we showed that while ducklings at TN show only a modest decline in daily thermoregulatory parameters when fasted, they exhibit reduced surface temperatures from key sites of vascular heat exchange during fasting. The CA birds, on the other hand, significantly reduced their short-term variations of body temperature while increasing long-term variability when fasting. This phenomenon would allow the CA birds to reduce the energetic cost of body temperature maintenance under fasting. By analysing ultradian regulation of body temperature, we describe a means by which an endotherm appears to lower thermoregulatory costs in response to the combined stressors of cold and fasting.

scholarly journals The Evolutionarily Conserved Gonadotropin-Releasing Hormone II Modifies Food Intake

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 686-691 ◽  
Author(s):  
Alexander S. Kauffman ◽  
Emilie F. Rissman
Keyword(s):  
Food Intake ◽  
Food Restriction ◽  
Similar Function ◽  
Structural Variants ◽  
Short Term ◽  
Primate Brain ◽  
Evolutionarily Conserved ◽  
Ad Libitum ◽  
Ad Libitum Feeding ◽  
Permissive Role

Abstract GnRH is an evolutionarily conserved peptide of which there are multiple structural variants. One form, GnRH II, is the most widespread in vertebrates, but its primary function remains unclear. In female musk shrews, administration of GnRH II, but not GnRH I, reinstates mating behavior previously inhibited by food restriction. Because this finding suggests that the function of GnRH II may be linked to energetic status, we tested whether GnRH II directly affects food intake. Adult female musk shrews were maintained on ad libitum feeding or food restricted for 48 h, after which they were infused centrally with GnRH I (1 μg), GnRH II (1 μg), or saline. Food intake was recorded 90 min, and 3, 6, 24, and 48 h after infusion. GnRH II administration, but not saline or GnRH I, reduced 24-h food intake in ad libitum animals. Short-term food intake (90 min and 3 h) of both ad libitum and underfed shrews receiving GnRH II was also reduced by as much as 33%, relative to the food intake of saline-infused controls. GnRH I infusion did not affect short-term food intake differently than saline infusion in shrews fed ad libitum. In underfed females, GnRH I had an effect on short-term food intake that was intermediate to saline and GnRH II. We conclude that, in addition to its permissive role in regulating reproduction, GnRH II may also modulate food intake in mammals. Because GnRH II is present in primate brain, it may also serve a similar function in humans.

The effect of providing a high fibre diet on foraging behaviour of outdoor sows and consequent pasture damage

1995 ◽  
Vol 1995 ◽  
pp. 32-32
Author(s):  
J P Braund ◽  
S A Edwards ◽  
I Riddoch ◽  
L Buckner ◽  
J Roden
Keyword(s):  
Foraging Behaviour ◽  
Alternative Methods ◽  
Food Level ◽  
Short Term ◽  
The Past ◽  
Fibre Diet ◽  
High Fibre ◽  
Welfare Implications ◽  
Ad Libitum ◽  
Fibrous Diet

Food restricted sows under extensive conditions forage for considerable periods of time and this can give rise to serious pasture damage. This pasture damage can be diminished by the reduction of rooting behaviours. In the past this has been achieved by nose ringing but, due to welfare implications, the emphasis has now been shifted onto alternative methods such as nutritional modification. This rooting behaviour is, in part, caused by hunger (feed motivation) and it has been demonstrated that this feed motivation can be manipulated by short-term changes in food level and type (Brouns et al 1994; Edwards et al, 1993; Ewbank, 1974).The objective of this experiment was to study the effects of feeding a fibrous diet (containing 600 g/kg unmolassed sugarbeet pulp) either at a restricted or ad libitum level, on foraging behaviour and the consequences of this for pasture damage.

Restricted feeding of egg-strain chickens during growth and throughout an extended laying period

1978 ◽  
Vol 18 (94) ◽  
pp. 658 ◽  
Author(s):  
D Robinson ◽  
G Horsnell ◽  
PJ McMahon
Keyword(s):  
Food Intake ◽  
Economic Performance ◽  
Egg Production ◽  
Restricted Feeding ◽  
Gross Margin ◽  
Mortality Cost ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Access To Food ◽  
Ad Libitum Feeding

White Leghorn x Australorp crossbred pullets were either fed ad libitum or given restricted access to food from 8 to 20 weeks of age. Birds from each of these rearing treatments were thereafter distributed among five feeding regimes: ad libitum and four allowances representing reductions of 3, 6, 12 and 24 per cent of the food intake of the birds fed ad libitum throughout life. Biological and economic performance data were examined for the rearing period and for three periods of lay terminating at 66, 78 and 90 weeks of age. From 8 to 20 weeks of age the restrictively reared pullets ate 30.5 per cent less food, suffered 1.7 per cent higher mortality, cost 19 cents per bird less to rear and were 20.5 per cent lighter in weight at 20 weeks than the pullets fed ad libitum. Compared with ad libitum feeding, restricted feeding in the rearing period gave higher values for hen-housed egg production and hen-housed gross margin when food intake in lay was restricted by 0, 3 and 6 per cent, and lower values for these criteria when food intake in lay was restricted by 12 and 24 per cent. Birds whose food intake was restricted by 6 per cent in the laying period laid about 25 more eggs to 90 weeks of age than birds fed ad libitum in lay. Optimum slaughter time (age at which average gross margin per week was maximized) was at about week 90 for the ad libitum/12 per cent restriction and ad libitum/24 per cent restriction treatments, and between weeks 66 and 78 for all other treatments. The highest weekly average gross margin was achieved with the birds that were restrictively reared and restricted by 6 per cent throughout a laying period terminating at 78 weeks of age; at this stage their gross margin was $2.30 per bird higher than that of the birds fed ad libitum throughout life

Sexual Development in Male Rats Treated With Cortisone

1957 ◽  
Vol 188 (2) ◽  
pp. 281-286 ◽  
Author(s):  
Russell O. Hanson ◽  
Ben B. Blivaiss ◽  
Robert E. Rosenzweig
Keyword(s):  
Body Weight ◽  
Male Rats ◽  
Ventral Prostate ◽  
Prostate Weight ◽  
Immature Male ◽  
End Of Treatment ◽  
Feeding Regimes ◽  
Pituitary Glands ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Immature male rats were treated with 1.0 mg cortisone acetate daily for 2 or 4 weeks starting at 23 days of age and were maintained on paired or ad libitum feeding regimes. Body, adrenal and thymus weights were reduced as compared to control animals. Actual testes weights were usually reduced less than body, liver or kidney weights. The ratios of testicular to body weight were significantly increased in the animals autopsied at the end of treatment. Histological examination of the testes revealed no significant alterations from normal. The ratios of seminal vesicle and ventral prostate weight to body weight were significantly decreased in all groups of ad libitum-fed animals and in pair-fed group autopsied at the end of 2 weeks of treatment. There were no significant changes in the other pair-fed groups. No modifications were observed in the histology of these organs. Pituitary glands removed from pair-fed animals at end of treatment with cortisone for 2 weeks appeared to have a higher GTH content than in the controls as indicated by the growth of the ovaries of immature rats injected with suspensions of these glands. Pituitary glands taken from other pair-fed groups and from all ad libitum-fed groups usually showed a lesser GTH content than in controls.

scholarly journals EFFECT OF FEED RESTRICTION AND REALIMENTATION ON NUTRIENT UTILIZATION AND CARCASS COMPOSITION OF ZEBU BULLS

2021 ◽  
Vol 16 ◽  
pp. 55-60
Author(s):  
O. W. Ehoche ◽  
W. S. Alhassan ◽  
V. Buvanendran ◽  
J. E. Umoh ◽  
N. N. Umanna
Keyword(s):  
Crude Protein ◽  
Nutrient Utilization ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Feed Restriction ◽  
Feeding Regimes ◽  
Digestible Crude Protein ◽  
Compositional Changes ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Forty-eight Sokoto Gudali bulls were used to study carcass compositional changes and nutrient efficiency following feed restriction (25% ad libitum feeding, L., and 54% ad. libitum feeding, M) and realimentation (ad. libitum feeding, H). The treatments were designated as LLH, LMH and LHH according to the level of feeding for each of three periods within each treatment group. Representative bulls were slaughtered at the beginning of the study and at the end of each feeding period. At the end of the mid period, animals on the LLH and LMH feeding regimes had higher percentages of water, similar percentages of protein and ash but lower proportions of fat and energy compared to animals on the LHH feeding regime. Following realimentation in the final period carcass gains contained approximately 21.0, 15.0, 18.5% protein and 22.0, 31,0 and 29.6% fat for LLH, LMH and LHH bulls respectively. The LHH animals were more efficient in utilizing metabolizable energy for carcass energy gain than the LLH and LMH animals. Digestible crude protein (DCP) efficience for carcass protein gain averaged 17.6, 26.2 and 35.4 g DCP/g protein gain for LLH, LMH and LHH bulls respectively. The results suggest that improved efficiency of protein utilization is largely responsible for compensatory carcass growth in zebu bulls. 

Modulation of maximum thermogenesis by feeding in the white rat

1980 ◽  
Vol 49 (6) ◽  
pp. 975-978 ◽  
Author(s):  
L. C. Wang
Keyword(s):  
Cold Exposure ◽  
Specific Dynamic Action ◽  
Self Control ◽  
Limiting Factor ◽  
Acute Cold Exposure ◽  
Feeding Regimes ◽  
Overnight Fasting ◽  
Ad Libitum ◽  
Ad Libitum Feeding ◽  
Cardiovascular Functions

The present study investigated the availability of substrates as a limiting factor in acute cold exposure. By use of a self-control experimental design, thermogenesis was measured in rats at -10 degrees C under 21% O2-79% He following different feeding regimes. Overnight fasting resulted in the lowest total heat production (9,949 +/- 189 cal/120 min, mean +/- SE, n = 11), maximum rate of thermogenesis (1,320 +/- 23 cal/15 min), and final body temperature (31.0 +/- 0.3 degrees C). The values were significantly lower than those found after overnight rationing (10,630 +/- 231, 1,386 +/- 29, and 32.8 +/- 0.5, respectively) or ad libitum feeding (10,821 +/- 224, 1,395 +/- 27, and 33.5 +/- 0.3). Rats fasted overnight but fed intragastrically a 5-ml substrate mixture (3 kcal/ml) 60 min prior to cold exposure resulted in the highest values for all parameters (11,553 +/- 207, 1,488 +/- 23, and 33.7 +/- 0.4). The increases were not due to the specific dynamic action of food. Since the levels of maximum thermogenesis and cold tolerance can be modulated by feeding, it is evident that substrate availability limits thermogenesis in severe cold independent of respiratory-cardiovascular functions and cellular oxidative capabilities.

scholarly journals Video surveillance methods to evaluate individual feeding response in rainbow trout (Oncorhynchus mykiss, Walbaum)—implications for feeding regime optimisation

2021 ◽  
Author(s):  
Philip Niclas Just ◽  
Bernd Köllner ◽  
Matthew James Slater
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Video Surveillance ◽  
Average Weight ◽  
Short Term ◽  
Feeding Regime ◽  
Daily Feeding ◽  
Juvenile Rainbow Trout ◽  
Feeding Regimes ◽  
The Impact

AbstractPrecisely analysing and optimising feeding regimes is central to salmonid growth performance and delivery of special diets. The current study developed novel video surveillance methods and analysis techniques to assess individual feed intake and minimum pellet intake (MPI) in individually identified juvenile rainbow trout, Oncorhynchus mykiss. Three trials were conducted to test the impact of short-term starvation (N=112 [16 tanks, 7 fish per tank], average weight=27.1±3.4g, age= 119 days), portion numbers per feeding (N=105 [15 tanks, 7 fish per tank], average weight=22.8±2.1g, age= 99 days) and varied numbers of daily feeding events (N=84 [12 tanks, 7 fish per tank], average weight=32.4±3.3g, age= 133 days). All trails were carried out in a recirculating aquaculture system with 20 tanks held at 15 ± 0.5°C. All individuals were code-tagged and high quality video images were taken and analysed to identify all feeding interactions. Individual trout feeding activity under different feeding regimes could be precisely analysed with the video methods developed. Moving from one to two daily feeding events doubled pellet intake per fish from 27.4 ± 5.8 to 52.8 ± 11.5 pellets. Pellet intake (58.8 ± 24.2 pellets) did not increase at three daily feeding events but became more variable across fish. MPI nearly doubled to 30 pellets in fish receiving two daily feeding events (MPI30: chi-squared = 8.74, df = 2, p = 0.01). Short-term starvation had no influence on intake (28 ± 8 pellets/fish) or MPI. Increasing portion number from one (27.8 ± 7.4 pellets fish−1) to two (31.1 ± 7.4 pellets fish−1) or more did not significantly increase the number of ingested pellets. Adjusting the feeding regime by increasing daily feeding events to two, possibly combined with multiple portions, can increase pellet intake and reduce the heteroscedasticity of pellet intake. The methods presented in this study are viable for analysing feeding regimes for juvenile rainbow trout and controlled feedstock/supplement delivery. Implications for analyses with other species and for vaccination optimisation are discussed.

The effects of environmental temperature and method of feeding on the performance and carcass composition of bacon pigs

1967 ◽  
Vol 9 (2) ◽  
pp. 209-218 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey
Keyword(s):  
Environmental Temperature ◽  
Average Daily Gain ◽  
Carcass Composition ◽  
Restricted Feeding ◽  
Feed Conversion ◽  
Feeding Method ◽  
Feeding Regimes ◽  
Higher Temperature ◽  
Ad Libitum ◽  
Environmental Temperatures

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.

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