Simulation of growth in pigs: evaluation of a model to relate thermorégulation to body protein and lipid content and deposition

1999 ◽  
Vol 68 (4) ◽  
pp. 655-679 ◽  
Author(s):  
P.W. Knap
Keyword(s):  
Food Intake ◽  
Metabolizable Energy ◽  
Critical Temperatures ◽  
Activity Increase ◽  
Body Protein ◽  
Ad Libitum ◽  
Tissue Insulation ◽  
Minimum Heat

AbstractA dynamic model for simulation of growth in pigs was extended by a module to assess maximum and minimum heat loss (HLcold, HLhot) for a given pig, to compare these figures to heat production (HP), and to take thermoregulatory action when HP< HLcold(cold conditions) or HP> HLhot(hot conditions).HLcoldand HLhotwere largely determined according to algorithms obtained from the literature, hut HLcold was made dependent on body fat depth through tissue insulation. Data to establish the relation (Ύ = 0.05 + 0.002 x X) between cold tissue insulation (Ύ in °C.m2per W) and backfat depth (X in mm) independent of body weight were obtained from the literature. The same data showed that HLhotis not related to backfat depth in pigs.Cold thermoregulatory action included an increase of ad libitum food intake. Hot thermoregulatory action included reduction of physical activity, increase of body temperature, wetting of a proportion of the skin and reduction of dia libitum food intake.A sensitivity analysis showed that the model’s output in terms of ãd libitum food intake, HP, protein deposition (Pdep) and lipid deposition (Ldep) is strongly sensitive to the characterization of the genotype being simulated. The model was used to simulate trials from the literature. Although the model does not explicitly calculate lower and upper critical temperatures, these could be adequately predicted from its output. Comparison of model output with experimental data revealed an adequate prediction of ad libitum food intake and of the partitioning of ad libitum ingested metabolizable energy (ME) into HP, Pdepand Ldepin cold, thermoneutral and hot conditions. At restricted ME intake, and especially in cold conditions, the model tends to overestimate HP and underestimate Ldep, probably because it does not take account of long-term acclimatization.

Effects of food intake and composition on the concentration of glucose in the blood of lactating cattle

1977 ◽  
Vol 28 (2) ◽  
pp. 333 ◽  
Author(s):  
TJ McClure
Keyword(s):  
Blood Glucose ◽  
Food Intake ◽  
Rice Straw ◽  
Feed Intake ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Metabolizable Energy ◽  
Lactating Cows ◽  
Maize Meal ◽  
Ad Libitum

A group of 16 cows, each suckling one calf, were fed on rations composed of maize meal, cottonseed meal, urea and rice straw in one of four different ratios and at two levels, (a) ad libitum and (b) in restricted amounts. The composition of the feed affected intake. Both the gross intake and the estimated intake of metabolizable energy were closely correlated with liveweight change. The intake of metabolizable energy was correlated with blood glucose in the cows fed ad libitum, but not in the cows fed on restricted amounts of the rations. It was concluded that feed quality significantly affected the blood glucose concentration of the lactating cows, but that within the ranges used in this experiment, feed intake and the intake of metabolizable energy had little effect.

P0919CALORIC RESTRICTION DOES NOT PROTECT AGAINST THE DEVELOPMENT OF VASCULAR CALCIFICATION

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Rafael Ríos-Varo ◽  
Ángela Vidal ◽  
Ana Isabel Raya ◽  
Carmen Pineda ◽  
Ignacio López ◽  
...  
Keyword(s):  
Food Intake ◽  
Vascular Calcification ◽  
Control Diet ◽  
Plasma Concentrations ◽  
Caloric Intake ◽  
Metabolizable Energy ◽  
High Rate ◽  
Caloric Content ◽  
Ad Libitum ◽  
Group 1

Abstract Background and Aims Vascular calcification (VC) is an important contributor to the high rate of cardiovascular mortality associated to chronic kidney disease. The inability to eliminate phosphorus (P) and the subsequent P retention promotes CV. P metabolism and uremic VC are influenced by obesity and by the caloric content of the diet. Caloric restriction (CR) has been shown to have multiple beneficial effects on health, for example, CR has been reported to improve vascular health and retard vascular ageing. However, to our knowledge the effect of CR on the development of uremic VC has not been explored. We hypothesize that CR may be beneficial to prevent the development of uremic VCs. Thus, the objective of the present study was to determine if rats subjected to CR were protected against VC. Method 48 Wistar rats were divided in four groups. The control diet provided Metabolizable Energy = 3.528 kcal/g and contained 0.6% Calcium (Ca) and 0.6% P. Additional diets of identical composition to the control diet but containing varying levels of Ca and P: 0.9% Ca, 0.9% P; 0.6% Ca, 1.2% P; and 0.9% Ca, 1.8% P, were also used in the experiments. Rats in Group 1 and 3 were fed 15 g/day of the control diet. Rats in Group 2 and 4 were calorie restricted and fed 10 g/day of diet with Ca/P = 0.9%/0.9%. Thus the daily P intake should be identical in the four groups. Uremia was induced by 5/6 nephrectomy (Nx). After Nx rats in Group 1 and 2 were fed ad libitum a diet with 0.6% Ca and 1.2% P. While rats in Group 3 and 4 were fed ad libitum a diet with 0.9% Ca and 1.8% P. Rats were supplemented with calcitriol. At the end of the experiment, rats were sacrificed to obtain blood samples and tissue samples (thoracic and abdominal aortas). After blood collection, plasma was separated by centrifugation and stored at –20° C until assayed. Plasma creatinine, Ca and P were measured by spectrophotometry. Energy intake was calculated based on food intake. VC was studied by histology and by measuring the tissue Ca content. Values are expressed as mean ± standard error (SE), the difference between groups was assessed by ANOVA. Fisher LSD test was used as a post-hoc procedure. p&lt;0.05 was considered significant. Results Before Nx, caloric intake was significantly lower in calorie restricted rats (35.4 ± 0.1 and 35.8 ± 0.1 kcal/day) than in rats eating normal calories (52.7 ± 0.1 and 52.8 ± 0.2 kcal/day); however, P intake was almost identical in the four groups and ranged between 89.8 and 91.6 mg/day. After Nx, rats in all groups reduced food intake and, consequently, caloric intake. Thus, although the P content of the diet was increased after Nx, daily P intake was not increased in Groups 1 and 2; however, P intake was significantly increased in Groups 3 and 4 (120.9 ± 4.6 and 122.2 ± 6.2 mg/day, respectively). In all groups, rats had high plasma concentrations of creatinine and P, and low plasma concentrations of Ca. Also, all rats had elevated Ca content in the aorta. No significant differences between the study groups were found in any of these parameters (Table 1). Von Kossa staining of the aortas showed abundant mineral deposition in the four groups. Conclusion This study shows that, contrary to what was expected, CR did not prevent or ameliorate uremic calcifications.

Intake and utilization of food by growing sheep with abomasal damage caused by daily dosing with Ostertagia circumcincta larvae

1977 ◽  
Vol 88 (3) ◽  
pp. 671-677 ◽  
Author(s):  
A. R. Sykes ◽  
R. L. Coop
Keyword(s):  
Food Intake ◽  
Protein Metabolism ◽  
Specific Effect ◽  
Infected Sheep ◽  
Metabolizable Energy ◽  
Apparent Digestibility ◽  
Infective Larvae ◽  
Gross Efficiency ◽  
Mineral Deposition ◽  
Ad Libitum

SUMMARYFour groups of eight sheep, 4 months of age and reared parasite-free from birth, were used to investigate the effect of the abomasal parasite Ostertagia circumcincta on the intake and efficiency of utilization of food. One group (CI) was killed initially as control. Two further groups (ALC and ALI) were offered ad libitum a complete ruminant diet. The ALI group was dosed daily for 14 weeks with 4000 infective larvae. Sheep in a further group (PF) were individually paired to members of the ALI group and offered the same amount of food as was consumed by their pair. Balances of N, Ca and P, and the digestibility of energy and N were determined for the ALI and PF groups during weeks 2–3, 7–8 and 12–13. After 14 weeks of dosing the sheep were killed and the bodies of these and the CI sheep analysed for water, fat, N, Ca and P contents.Parasitism caused a 20% reduction of food intake by week 2 which was maintained throughout the experiment. Apparent digestibility of nitrogen was reduced from 60 to 44% at weeks 2—3 but subsequently showed a gradual recovery. Nitrogen balances of infected sheep were inferior to those of controls which, with the exception of the first trial during which urinary N excretion of infected sheep was increased, was entirely related to the reduced digestibility. Energy digestibility was reduced by 2 percentage units during all trials.Weight gain of ALI sheep was only 80% of that of PF sheep. Nitrogen anabolism was reduced by parasitism, but pair-feeding showed that reduced food intake rather than a specific effect on protein metabolism was responsible. Fat deposition was markedly reduced. It was calculated that the gross efficiency of utilization of metabolizable energy for growth was reduced by 30% compared with either ALC or PF controls.Mineral deposition (Ca or P) in the skeleton of the ALI sheep was reduced to about 35 and 50% of that in ALC and PF groups, respectively.

Interrelationships between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model

1977 ◽  
Vol 24 (1) ◽  
pp. 91-101 ◽  
Author(s):  
J. M. Forbes
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Abdominal Fat ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Final Body Weight ◽  
Pregnancy And Lactation ◽  
Endocrine Factors ◽  
Ad Libitum ◽  
Voluntary Food Intake

SUMMARYA model has been developed in which the voluntary food intake of sheep is related directly to metabolizable energy requirements unless physical or endocrine limitations intervene.Although no ‘set point’ for body weight or body fat is incorporated in the model, mature sheep offered food ad libitum are predicted to reach eventually a plateau of body weight due to progressive depression of gut capacity by the increasing volume of abdominal fat. The final body weight is proportional to the digestibility of the diet. During pregnancy and lactation metabolic, physical and endocrine factors interact in such a way as to give predicted patterns of feed intake similar to those observed in practice with several qualities of diet.

scholarly journals Possibilities for Maintaining Appetite in Recovering COVID-19 Patients

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 464
Author(s):  
Alexander Teymour Zadeh Baboli Høier ◽  
Nora Chaaban ◽  
Barbara Vad Andersen
Keyword(s):  
Food Intake ◽  
Well Being ◽  
Long Term Effects ◽  
Hedonic Value ◽  
Trigeminal Stimulation ◽  
Health Promoting ◽  
Desire To Eat ◽  
Depth Interviews

COVID-19 and sequelae thereof are known to cause chemosensory dysfunction, posing a risk for intake and adequate nutrition for recovery. The overall objective of this study was to investigate the subjective strategies for maintaining appetite applied by patients recovering from COVID-19. The study included 19 in-depth interviews, focusing on patients suffering from long-term effects of COVID-19. The results were analysed using a thematic analysis for qualitative data. Results on strategies for maintaining appetite included four key themes: (1) a focus on well-functioning senses, (2) a focus on familiar foods, (3) a focus on the eating environment, and (4) a focus on post-ingestive well-being. It was found that factors prior to, during and after food intake, as well as the context, could influence desire to eat and pleasure related to food intake. As ageusia and anosmia make characterization of food difficult, being able to recognize and memorize its flavour was important to engage in consumption. Under normal circumstances, the hedonic value of food relies predominantly on the flavour of foods. When suffering from chemosensory dysfunction, shifting focus towards the texture of food, including trigeminal stimulation during consumption, were beneficial for maintaining appetite and food-related pleasure. Furthermore, a focus on the holistic satisfying feelings of choosing healthy food, as well as a focus on other people’s enjoyment during meals were reported to boost well-being around food intake. The study elaborated our understanding of the complex consequences of COVID-19, and can be applied in health promoting initiatives targeted patients recovering from COVID-19.

Growth in sheep. II. Efficiency of energy and nitrogen utilization from birth to 2 years

1972 ◽  
Vol 79 (3) ◽  
pp. 383-389 ◽  
Author(s):  
N. McC. Graham ◽  
T. W. Searle
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Metabolizable Energy ◽  
Wool Growth ◽  
Daily Food ◽  
Restricted Group ◽  
Ad Libitum ◽  
Energy Gains ◽  
Age Range ◽  
Milk Feeding

SUMMARYThirty sheep were pen-fed from age 2 days to nearly 2 years. Fifteen were fed ad libitum and the others were restricted to half that rate, age for age; daily food intakes were recorded. Sequential estimates of body composition were made on each sheep so that protein and energy gains could be obtained for specified age ranges.In the sheep fed ad libitum, food intake increased several fold in the first few months of life but was relatively constant from 4 months despite large increases in body weight. Thus intake per kg¾ declined progressively as the sheep grew.The data for the well fed and restricted groups were combined within each age range and linear regression was used to relate body growth (protein and energy) to food intake, variates being expressed as multiples of body weight (kg¾). Energy gain was zero when intake was 250–590 kJ metabolizable energy/day kg¾, depending on age. Wool growth per unit food intake was constant for each sheep throughout the experiment but was twice as great in some sheep as in others and was higher in the restricted group.Efficiency of energy and protein utilization declined at weaning but otherwise did not vary much with stage of growth. Approximately 40% of energy storage was in protein during milk feeding; after weaning, the fraction declined from 25 to 10% (30 to 20% including wool protein) as the sheep grew.

Characterization of post-weaning traits of Simmental and Hereford bulls and heifers

1984 ◽  
Vol 39 (3) ◽  
pp. 355-364 ◽  
Author(s):  
T. G. Jenkins ◽  
C. L. Ferrell
Keyword(s):  
Growth Rate ◽  
Chemical Composition ◽  
Dry Matter ◽  
Carcass Characteristics ◽  
Metabolizable Energy ◽  
Dry Matter Intake ◽  
Food Conversion ◽  
Ad Libitum ◽  
Food Conversion Efficiency

ABSTRACTPost-weaning growth, dry-matter intake, carcass characteristics, chemical composition of the 9th to 11th rib section and food conversion efficiency were evaluated for Simmental bulls (15) and heifers (18) and Hereford bulls (17) and heifers (14) from approx. 240 days of age to 470 days of age. Within each breed × sex sub-class, animals were assigned to one of three energy intake levels: (1) ad libitum, (2) 795 kJ metabolizable energy (ME) per kg0·75 per day and (3) 544 kj ME per kg0·75 per day.Simmentals tended to exhibit higher post-weaning growth rate and consumed more dry matter than Herefords. At ad libitum intakes, efficiency estimates (gain/food) were greater initially but decreased more rapidly for Herefords than for Simmentals. No differences were observed in efficiency estimates between Herefords and Simmentals fed at 795 kJ ME per kg0·75 per day and both breeds fed at this level improved in efficiency as time on test increased.Bulls tended to have greater growth rate, and consume more dry matter than heifers. At ad libitum food intake, bulls were more efficient than heifers and the decrease in efficiency of the two sexes was parallel. Heifers fed at 795 kJ ME per kg0·75 per day had a constant efficiency throughout the test while bulls improved in efficiency.

Area postrema lesion attenuates the long-term hypotensive effects of losartan in salt-replete rats

1998 ◽  
Vol 274 (2) ◽  
pp. R357-R366 ◽  
Author(s):  
John P. Collister ◽  
John W. Osborn
Keyword(s):  
Food Intake ◽  
Sham Group ◽  
Area Postrema ◽  
Recovery Period ◽  
Receptor Blockade ◽  
Conscious Rat ◽  
Sham Surgery ◽  
Ad Libitum ◽  
Access To Food

We reported that the AT1 receptor antagonist losartan decreases arterial pressure in sodium-replete rats and that this response is attenuated in area postrema-lesioned (APx) rats (J. P. Collister, B. J. Hornfeldt, and J. W. Osborn. Hypertension 27: 598–606, 1996). In that study, food intake for the 3-wk period after sham lesion was restricted to that observed in APx rats. Food-restricted sham rats had lower arterial pressures and attenuated responses to losartan compared with control rats fed ad libitum. The present study examined whether these differences persisted months, rather than weeks after APx or sham lesions. Losartan was administered for 10 days to APx and two groups of sham rats 3 mo after APx or sham surgery. The first sham group was food restricted (SFR) for 3 wk after surgery, whereas the second sham group was allowed ad libitum (SAL) access to food. By day 8of losartan administration, both sham groups demonstrated a marked hypotension (SFR: −38 ± 4; SAL: −33 ± 4 mmHg). This response was attenuated ( P < 0.05) on the same day in APx rats (−17 ± 3 mmHg). This trend continued throughout days 9 and 10. Because both sham groups responded similarly to losartan (yet significantly different from APx rats), these results demonstrate that transient decreases in food intake do not affect the response to losartan if rats are allowed an adequate recovery period. We conclude that the area postrema mediates part of the long-term hypotensive effects of AT1 receptor blockade in the conscious rat.

scholarly journals Effects of long-term intervention with low- and high-glycaemic-index breakfasts on food intake in children aged 8–11 years

2007 ◽  
Vol 98 (3) ◽  
pp. 636-640 ◽  
Author(s):  
C. Jeya K. Henry ◽  
Helen J. Lightowler ◽  
Caroline M. Strik
Keyword(s):  
Food Intake ◽  
Energy Intake ◽  
Dietary Fibre ◽  
Glycaemic Index ◽  
Daily Energy ◽  
Food Diaries ◽  
The Mean ◽  
Ad Libitum ◽  
The Difference

The aim of the present study was to investigate the effects of long-term intervention of low-glycaemic-index (GI) v. high-GI breakfasts on energy and macronutrient intakes in children aged 8–11 years. Preadolescent children were assigned to one of two groups in a random cross-over design. Each group was given low-GI and high-GI breakfasts on two non-consecutive days per week for 10 weeks per breakfast type. Each breakfast provided approximately 1273 kJ (300 kcal) and was closely matched for macronutrient and dietary fibre content. Subsequent food intake at an ad libitum buffet lunch was recorded and daily energy and macronutrient intakes were measured by 24 h recall and 3 d food diaries. There was a tendency towards a reduced energy intake at lunch following the low-GI breakfast compared with the high-GI breakfast, although the mean difference of 75 kJ (18 kcal) was not significant (P = 0·406). In particular, there was a trend towards a reduced energy intake in the low-GI arm compared with the high-GI arm among boys. In addition, data from the 3 d food diaries showed that there was a tendency towards a reduced energy intake during the low-GI compared with the high-GI study period. In conclusion, although the difference in energy intake following the low-GI and high-GI breakfasts was not statistically significant, the reduced energy intake following the low-GI breakfast is encouraging. Both dietary fibre and carbohydrate type may affect GI, thus their potential and relative modulating effect on appetite requires further investigation.

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