The influence of dietary protein and caloric content on thyroid function and hepatic thyroxine 5′-monodeiodinase activity in rainbow trout, Oncorhynchus mykiss

1992 ◽  
Vol 70 (8) ◽  
pp. 1526-1535 ◽  
Author(s):  
J. G. Eales ◽  
D. L. MacLatchy ◽  
D. A. Higgs ◽  
B. S. Dosanjh
Keyword(s):  
Rainbow Trout ◽  
Protein Content ◽  
Thyroid Function ◽  
Dietary Protein ◽  
Protein Intake ◽  
Caloric Intake ◽  
Metabolizable Energy ◽  
Caloric Content ◽  
Substrate Affinity ◽  
Isocaloric Diets

The influence of dietary protein and caloric intake on thyroid function of immature rainbow trout (6.5 °C; 12 h L: 12 h D photocycle) fed a daily ration of 0.97% of body weight was studied. In experiment 1, trout fed four isocaloric diets (~ 3300 kcal of estimated metabolizable energy/kg; 1 cal = 4.1855 KJ) of identical digestible carbohydrate content (15.2%) but with varying percentages of lipid (7.5–17.6%) and protein (25.6–47.5%) exhibited negligible or modest changes in plasma L-thyroxine (T4) or 3,5,3′-triiodo-L-thyronine (T3) after 7 or 35 days. After 14 days, activity of hepatic 5′-monodeiodinase (5′D), which converts T4 to the active T3 form, was unaltered. However, at 38 days the functional level (Vmax) of 5′D was directly related to the level of protein intake. Substrate affinity (Km) was unchanged. In experiment 2, trout fed four isocaloric diets (~ 3575 kcal/kg) of similar lipid content (15.8%) but with varying percentages of digestible carbohydrate (3.6–54.2%) and protein (0.32–47.1%) generally showed unaltered plasma T4 after 7 or 35 days, but plasma T3 was depressed by the lowest dietary protein levels. Activity of 5′D was unaffected at 14 days, but at 38 days Vmax was directly related to the level of protein ingested; Km was not changed. Trout pair-fed diets of the highest protein content to achieve levels of protein intake equivalent to those of trout fed diets of lower protein content showed a depressed Vmax but no changes in Km or plasma T4 or T3 levels. We conclude that the level of protein intake in trout mainly determines the activity of 5′D, which is a more sensitive index of chronic thyroidal adjustment than plasma T4 or T3 levels. However, the amount of ingested protein relative to total available dietary energy and (or) the absolute intake levels of one or more nonprotein nutrients change 5′D activity, possibly by influencing the balance between protein synthesis and degradation.

The effects of dietary protein content on growth and maturation in deer mice

1999 ◽  
Vol 77 (11) ◽  
pp. 1822-1828 ◽  
Author(s):  
Andrew G McAdam ◽  
John S Millar
Keyword(s):  
Protein Content ◽  
Dietary Protein ◽  
Maternal Diet ◽  
Natural Populations ◽  
Female Offspring ◽  
Deer Mice ◽  
Nestling Growth ◽  
Protein Levels ◽  
In Captivity ◽  
Isocaloric Diets

Growth and female maturation appear to be limited by the availability of dietary protein in natural populations of deer mice (Peromyscus maniculatus borealis) in the Kananaskis Valley, Alberta. We examined the effects of dietary protein content on nestling growth rates and sexual maturation of female deer mice in two laboratory experiments. In the first, mice whose mothers were fed a low-protein mixture of sunflower seeds and oats (14% protein) exhibited slow growth prior to weaning and those fed high-protein cat food (30% protein) postweaning showed compensatory growth. Preweaning but not postweaning diet quality affected the proportion of females who were sexually mature at 42 days of age. Therefore, while deficient nestling growth can be compensated for, the effects of a low-quality maternal diet during lactation may have lasting effects on the maturation of female offspring. In the second experiment, mice raised on isocaloric diets of 14, 20, and 30% protein did not differ in growth as nestlings or juveniles. Differences among the three diets in the proportion of mature females at 42 days did not correspond to dietary protein levels as predicted. Dietary protein content from 14 to 30% appear to be sufficient for juvenile mice raised in captivity.

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<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.

scholarly journals The influence of proanthocyanidin-rich bean hulls and level of dietary protein on energy metabolizability and nutrient digestibility by adult cockerels

1993 ◽  
Vol 70 (1) ◽  
pp. 355-367 ◽  
Author(s):  
M. A. Longstaff ◽  
D. Feuerstein ◽  
J. M. McNab ◽  
C. McCorquodale
Keyword(s):  
Protein Content ◽  
Dietary Protein ◽  
Nutrient Digestibility ◽  
Metabolizable Energy ◽  
Starch Digestibility ◽  
Maize Starch ◽  
Low Levels ◽  
Significant Regression ◽  
Field Beans ◽  
Lipid Digestibility

Cotyledons and hulls were prepared from twelve varieties of field beans (Vicia faba L.). Adult cockerels were tube-fed either beans, cotyledons or hull diets containing high or low levels of protein. Metabolizable energy coefficients and starch digestibility coefficients were determined for beans, cotyledons and hull diets. Lipid digestibility coefficients from hull diets were also determined. When cotyledons were fed there were no significant differences in the way in which adult cockerels metabolized energy or digested starch from the proanthocyanidin-free and proanthocyanidin-rich varieties (0·780, 0·908, 0·775 and 0·918 respectively). When beans were fed, however, both energy metabolizability and starch digestibility decreased due to the presence of hulls, with proanthocyanidin-rich hulls decreasing values the most to 0·660 and 0·819 respectively, and proanthocyanidin-free hulls decreasing values to a lesser extent to 0·709 and 0·886 respectively. Diets composed of proanthocyanidin-rich hulls depressed metabolizable energy and maize starch digestibility. Their effect on maize starch digestibility, however, was considerably less than that on bean starch. Lipid digestibility was enhanced by proanthocyanidins but only when the protein content of the diet was high. There was a significant correlation (P < 0·05) between the vanillin and anthocyanidin formation methods for the estimation of proanthocyanidins (r 0·779). There was also a highly significant regression of bean starch digestibility v. proanthocyanidin content of coloured-flowered bean hulls (P < 0·001). The regression of maize starch digestibility v. hull proanthocyanidins was also significant at P < 0·005.

Human Milk—Protein—Prematurity

PEDIATRICS ◽  
1963 ◽  
Vol 31 (2) ◽  
pp. 342-342
Author(s):  
WALTER B. OMANS ◽  
LEWIS A. BARNESS ◽  
CATHERINE S. ROSE ◽  
PAUL GYÖRGY
Keyword(s):  
Human Milk ◽  
Protein Content ◽  
Protein Intake ◽  
Recent Article ◽  
Milk Protein ◽  
Weight Curve ◽  
Isocaloric Diets ◽  
Human Milk Protein

Sometimes, in order to make an article brief, authors quote others, but the interpretations of the new authors may not reflect the context of the original observers. This has occurred in the quotation of several of our papers in a recent article by Pincus et al. First we are quoted as agreeing "that small infants where fed isocaloric diets gain weight more rapidly on a diet having a higher protein content" (author references 12 and 16). In reference 12,2 we state that infants fed 3.0 to 8.0 gm of protein per kilogram gained equally well. Only when the protein intake was below 2.0 gm/kg did the weight curve not rise as well. Indeed, in this paper, we noted a few babies taking more than 8 gm/kg protein who gained very poorly.

scholarly journals The effect of the preceding day's protein intake on basal metabolic rates in young adults

1988 ◽  
Vol 60 (3) ◽  
pp. 425-431 ◽  
Author(s):  
M. J. Soares ◽  
Jennifer Sequeira ◽  
P. S. Shetty
Keyword(s):  
Young Adults ◽  
Individual Differences ◽  
Protein Content ◽  
Dietary Protein ◽  
Protein Intake ◽  
Significant Interaction ◽  
Training Effect ◽  
Metabolic Rates ◽  
Period Analysis ◽  
Significant Difference

1. Changes in basal metabolic rates (BMR), following alterations in the preceding day's dietary protein (8.6, 11.5 and 14.0% of energy) were studied in eight, young, healthy adults over 4d.2. Results showed a significant training effect, with BMR values 4.8 % lower on day 4 of the study period. Analysis of the results by ANOVA revealed a significant interaction between subjects and diets (P<0.005), a significant difference between subjects but no differences in BMR due to the protein content of the diets.3. Mean coefficient of variation (CV) for intra- and inter-individual differences in BMR from day-to-day was of the order of 4 and 9% respectively.4. Changes in protein content of the preceding day's diet do not influence variations in BMR which appear to be random in nature with a true CV of 3.8%.

The digestion of two diets of differing protein content but with similar capacities to sustain wool growth

1967 ◽  
Vol 18 (6) ◽  
pp. 973 ◽  
Author(s):  
JP Hogan ◽  
RH Weston
Keyword(s):  
Organic Matter ◽  
Protein Content ◽  
Dietary Protein ◽  
Protein Intake ◽  
Crude Protein ◽  
Alimentary Tract ◽  
Soluble Carbohydrate ◽  
Cellulose Digestion ◽  
Low Protein ◽  
Wool Growth

Measurements were made of the digestion in sheep of two diets of differing protein content but known to support similar levels of wool growth. When offered to the sheep at 500 g/day, the high protein (HP) diet provided 13.8 g nitrogen (N), while the low protein (LP) diet provided 5.5 g. With the HP diet, approximately 8.8 g N in forms other than ammonia passed daily through the pylorus; 6.8 g of this N was apparently digested in the intestines. The corresponding values for the LP diet were 8.1 and 6.2. The similarity in wool growth recorded with these diets, despite large differences in dietary protein intake, is consistent with the hypothesis that wool growth is limited by the quantity of amino acid N absorbed from the alimentary tract. The stomach was the site of 72–73 % of the organic matter digestion and more than 90% of the cellulose digestion that occurred in the whole alimentary tract. In addition, approximately 90% of the dietary soluble carbohydrate was apparently digested in the stomach. It was calculated, by making several assumptions, that the quantity of microbial crude protein synthesized in the rumen did not exceed 44–49 g/day, equivalent to 15–16 g/100 g organic matter digested in the rumen. The implications of this calculation in the protein nutrition of ruminants are discussed. The retention time of a soluble marker in the rumen was 15–18 hr, and rates of flow of digesta from the rumen and abomasum were comparatively low.

Thermogenesis in response to various intakes of palatable food

1986 ◽  
Vol 64 (7) ◽  
pp. 976-982 ◽  
Author(s):  
Jacques LeBlanc ◽  
Diane Lupien ◽  
Pierre Diamond ◽  
Marcos Macari ◽  
Denis Richard
Keyword(s):  
Caloric Intake ◽  
Metabolizable Energy ◽  
Cafeteria Diet ◽  
Caloric Content ◽  
Stock Diet ◽  
Palatable Food ◽  
Average Value ◽  
Brown Adipose ◽  
Significant Difference ◽  
The Cost

Complete energy balance studies were made on groups of overfed (A) and underfed (B) Wistar rats. In experiment A one group was fed cafeteria diet ad libitum (the intake was 29% larger than the control), two other groups were fed the same diet but in restricted quantities (18 and 9% above control), and a fourth group, fed a stock diet, served as control. In experiment B, caloric intake was restricted by 12 and 31% in two groups fed cafeteria diet, and by 21 and 34% in two other groups fed stock diet. The experiments lasted 41 days and during that period the protein gain was comparable between the control and the cafeteria-29% group (643.4 ± 33.3 vs. 578.1 ± 25.0) but the fat gain was significantly different between the two groups (863.2 ± 81.6 vs. 1663.2 ± 99.8 kJ). When energy expenditure (EE) (metabolizable energy less storage added to the cost of storage) is expressed as a percentage of metabolizable energy (ME) intake no significant difference was found among the groups. The average value was [Formula: see text]. This finding would not support the presence of dietary-induced thermogenesis in animals overfed on the cafeteria diet. However, since the obligatory cost associated with storing energy would not explain the higher EE of the overfed groups, it is suggested that the level of ME intake exerts continuous proportional regulatory action on EE and, as a result, energy is spared by underfeeding and it is wasted by overfeeding. Rats fed the cafeteria diet, independent of whether they are overfed or restricted were shown to increase both brown adipose tissue (BAT) protein content and thermogenic capacity in response to norepinephrine. For that reason it is suggested that it is not the caloric content of the diet which affects BAT but instead other factors such as fat content or palatability of the food. The results also suggest that BAT is not directly implicated in the regulatory responses associated with various intakes of food. Indeed in the underfed experiment, although the capacity of the BAT was enhanced in the cafeteria groups, the EE was not different from that of the animals fed the stock diet.

scholarly journals A comparison of choice and phase feeding for growing–finishing pigs

1995 ◽  
Vol 75 (1) ◽  
pp. 93-98 ◽  
Author(s):  
D. S. Nam ◽  
F. X. Aherne
Keyword(s):  
Weight Gain ◽  
Protein Content ◽  
Feed Intake ◽  
Dietary Protein ◽  
Protein Intake ◽  
Finishing Pigs ◽  
Feeding System ◽  
Three Phase ◽  
Choice Feeding ◽  
Feeding Systems

A growing-finishing trial using 72 crossbred gilts (19.7 kg initially) was conducted to evaluate the effectiveness of choice feeding in the production of pigs. Six pens of three gilts were assigned to each of the following feeding systems: (1) conventional three-phase feeding (18–16–14% crude protein; P3), (2) one-phase feeding (16%; P1), (3) three-phase choice feeding (24–14, 22–12, 20–10%; C3) of two diets differing in protein level, and (4) one-phase choice feeding (24–10% throughout; CI). The three growth periods were 20–50, 50–70 and 70–105 kg live weight. All diets were based on barley and soybean meal and contained the same energy level (13.7 MJ DE kg−1). Choice feeding systems (C1 and C3) during the grower period (20–50 kg) increased (P < 0.05) feed intake (1.52 vs. 1.33 kg d−1) and weight gain (801 vs. 731 g d−1) compared with those of phase feeding (P1 and P3). In the 50–105 kg growth phase, feeding systems had no effect on pig growth performance. Feed intake over the entire period (20–105 kg) was higher (P < 0.05) with choice feeding (2.55 kg d−1) than with phase feeding (2.27). Dietary protein intake increased (P < 0.05) by 18% in choice-fed pigs, and more dietary protein was required (P < 0.05) for weight gain from choice feeding than from phase feeding. There were no significant differences in the protein content of the diets selected by C1 and C3 pigs for any period or for the overall experiment. There were no significant effects of feeding system on carcass traits, except that carcass dressing percentage was highest (P < 0.05) for C3 pigs. These results suggest that choice-fed pigs consumed more dietary protein and required more protein for weight gain than pigs in a phase feeding system. Also, growing–finishing pigs do not have the ability to select a protein intake to meet their requirement for protein when they are provided a choice of diets differing in protein content. There was no advantage to using a three-phase choice feeding system rather than a singe-phase choice system. Key words: Choice feeding, protein selection, performance, carcass characteristics, pigs

scholarly journals The effect of dietary protein content and feeding level on the rate of protein deposition and energy utilization in growing Iberian pigs from 15 to 50kg body weight

2002 ◽  
Vol 88 (1) ◽  
pp. 39-49 ◽  
Author(s):  
R. Nieto ◽  
A. Miranda ◽  
M. A. García ◽  
J. F. Aguilera
Keyword(s):  
Body Weight ◽  
Protein Content ◽  
Dietary Protein ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Feeding Level ◽  
Protein Deposition ◽  
Ideal Protein ◽  
Feeding Regimen

The effects of dietary protein content and feeding level on the utilization of metabolizable energy (ME) and on the rates of gain, protein and fat deposition have been studied in seventy-two Iberian pigs growing from 15 to 50 kg body weight (BW) by means of comparative slaughter experiments. The animals were fed on six diets providing 223, 192, 175, 156, 129 and 101 g crude ideal protein (N×6·25; CP)/kg DM and 14·64, 14·14, 14·37, 14·80, 15·36 and 15·53 MJ ME/kg DM respectively. Each diet was offered at three levels of feeding: 0·60, 0·80 and 0·95×ad libitum intake. Protein deposition (PD) increased significantly (P<0·01) with each decrease in dietary CP content and reached a maximum value (74·0 g) when the diet providing 129 g CP/kg DM (6·86 g digestible ideal protein/MJ ME) was offered at the highest feeding level. This feeding regimen resulted in average values for live-weight gain and retained energy (RE) of 559 g/d and 10·9 MJ/d respectively. RE increased significantly (P<0·001) from 480 to 626 kJ/kg BW0·75 with each decrease in dietary CP content from 192 to 129 g/kg DM. Raising the level of feed intake led to significant linear increases in PD and RE irrespective of the diet fed (P<0·001). When diets approaching an adequate supply of CP were given, the net efficiency of use of ME for growth (kw) and the maintenance energy requirements were 58·2 % and 422 kJ/kg BW0·75 per d respectively.

Sign in / Sign up

Export Citation Format

Share Document