Incorporating turn-over in whole body protein retention efficiency in cattle and sheep

2005 ◽  
Vol 80 (3) ◽  
pp. 345-351 ◽  
Author(s):  
C. Z. Roux
Keyword(s):  
Multiple Regression ◽  
General Rule ◽  
The Body ◽  
Whole Body ◽  
Regression Estimate ◽  
Retention Efficiency ◽  
Body Protein ◽  
Protein Retention ◽  
Limit Value ◽  
Turn Over

AbstractIn pigs the quantification of breakdown and synthesis by powers of body protein led to the estimation of turn-over related protein retention efficiency by the equation kP= {1 + [1 − (P/α)(2/9)Q]−1/6}−1, with α the limit value of whole body protein (P) maturity, so that 0 ≤(P/α)≤1. The factor 2/9 is derived from diffusion attributes indicated by cell and nucleus geometries α and Q represents a scaled transformation of intake, 0 ≤ Q ≤ 1, such that a value of Q = 1 may represent ad libitum intake and Q = 0 the intake at the maintenance requirement. Published observations on finishing steers provide estimates of whole body protein synthesis and breakdown at pre-determined levels of intake in confirmation of the theoretical (2/9)Q power associated with (P/α) inkP. Further confirmation of the (2/9)Q power in cattle follows from satisfactory agreement between an estimate of conventional multiple regression retention efficiency and the turn-over related retention efficiency calculated at the given level of intake, for the mid point of the body mass interval covered by the regression estimate. In addition, a simulation experiment on cattle from the literature gives power estimates of protein breakdown and synthesis in general agreement with those accepted for pigs. Examples on both fine and coarse diets are employed to suggest a general rule for prediction on diets causing submaximal efficiency due to suboptimal intakes.In sheep, evidence derived from estimates of conventional multiple regression efficiencies suggests that the rule (a-b) = (2/9) Q for the calculation ofkPshould be reserved for the description of compensatory growth. Protein retention efficiency for ordinary growth should be described by an adaptation of the rule derived for suboptimal intakes.

Incorporating turn-over in whole body protein retention ef.ciency in pigs

2005 ◽  
Vol 80 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Z. Roux
Keyword(s):  
Protein Synthesis ◽  
Growth Factor ◽  
Hormonal Control ◽  
Whole Body ◽  
Insulin Like Growth Factor ◽  
Retention Efficiency ◽  
Body Protein ◽  
Protein Retention ◽  
Limit Value ◽  
Turn Over

The magnitude of the discrepancy between conventional regression estimates of protein retention efficiency and theoretical estimates of synthesis efficiency indicates a major contribution ascribable to protein turn-over in the generally accepted estimates. As protein turn-over is known to be influenced by diet, feeding level and degree of maturity, this suggests the development of an estimator of protein efficiency that can be adapted for such differences. Therefore, based on generally accepted formulas for growth description, a method of estimating protein retention efficiency was developed which is flexible enough to accommodate different diets, feeding levels and degrees of maturity. Moreover, a formula was derived to convert one type of estimate to the other by regarding constant efficiency as equivalent to variable efficiency at the mid point of the estimation interval. Increase in scientific depth to this descriptive approach is provided by a theoretical consideration of a possible mechanism of hormonal control of protein synthesis and breakdown, ultimately expressed as proportionalities to powers of whole body protein (P). Molecular considerations on cellular synthesis and breakdown indicate a difference between breakdown and synthesis powers equal to (2/9)Q. The factor (2/9) is indicated by an argument based on insulinlike growth factor derived activator diffusion attributes by nucleus and body tissue geometries, whileQis equal to the proportion of nuclei activated by insulin-like growth factor. This proportion is likely to be a function of the concentration of growth factor in the blood. Hence, a linear relationship between intake and blood insulin-like growth factor concentration suggests thatQcan be represented by a scaled transformation of intake, 0 ≤Q≤ 1, such that a value ofQ= 1 represents ad libitum intake on a suitable diet andQ= 0 intake at the maintenance requirement. The quantification of breakdown and synthesis power differences by (2/9)Qleads to kP= {1 + [1 − (P/α)(2/9)Q]−1/6}−1, for turn-over related protein retention efficiency (kP), with α the limit value of P at maturity, so that 0 ≤ (P/α) ≤ 1. Experimental estimates, derived from direct estimates of whole body protein synthesis and breakdown at predetermined levels of intake, are in excellent agreement with the theoretical (2/9)Qin the power associated with (P/α) in kP. Furthermore, conventional multiple regression retention efficiencies satisfactorily approximate the turn-over related retention efficiency that can be calculated at a given level of intake for the mid point of the interval covered by the regression estimates.

Resistance training reduces whole-body protein turnover and improves net protein retention in untrained young males

2006 ◽  
Vol 31 (5) ◽  
pp. 557-564 ◽  
Author(s):  
Joseph W. Hartman ◽  
Daniel R. Moore ◽  
Stuart M. Phillips
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Nitrogen Balance ◽  
Protein Turnover ◽  
Whole Body ◽  
Body Protein ◽  
Protein Retention ◽  
The Impact ◽  
Net Protein ◽  
Urinary Nitrogen

It is thought that resistance exercise results in an increased need for dietary protein; however, data also exists to support the opposite conclusion. The purpose of this study was to determine the impact of resistance exercise training on protein metabolism in novices with the hypothesis that resistance training would reduce protein turnover and improve whole-body protein retention. Healthy males (n = 8, 22 ± 1 y, BMI = 25.3 ± 1.8 kg·m–2) participated in a progressive whole-body split routine resistance-training program 5d/week for 12 weeks. Before (PRE) and after (POST) the training, oral [15N]-glycine ingestion was used to assess nitrogen flux (Q), protein synthesis (PS), protein breakdown (PB), and net protein balance (NPB = PS – PB). Macronutrient intake was controlled over a 5d period PRE and POST, while estimates of protein turnover and urinary nitrogen balance (Nbal = Nin – urine Nout) were conducted. Bench press and leg press increased 40% and 50%, respectively (p < 0.01). Fat- and bone-free mass (i.e., lean muscle mass) increased from PRE to POST (2.5 ± 0.8 kg, p < 0.05). Significant PRE to POST decreases (p <0.05) occurred in Q (0.9 ± 0.1 vs. 0.6 ± 0.1 g N·kg–1·d–1), PS (4.6 ± 0.7 vs. 2.9 ± 0.3 g·kg–1·d–1), and PB (4.3 ± 0.7 vs. 2.4 ± 0.2 g·kg–1·d–1). Significant training-induced increases in both NPB (PRE = 0.22 ± 0.13 g·kg–1·d–1; POST = 0.54 ± 0.08 g·kg–1·d–1) and urinary nitrogen balance (PRE = 2.8 ± 1.7 g N·d–1; POST = 6.5 ± 0.9 g N·d–1) were observed. A program of resistance training that induced significant muscle hypertrophy resulted in reductions of both whole-body PS and PB, but an improved NPB, which favoured the accretion of skeletal muscle protein. Urinary nitrogen balance increased after training. The reduction in PS and PB and a higher NPB in combination with an increased nitrogen balance after training suggest that dietary requirements for protein in novice resistance-trained athletes are not higher, but lower, after resistance training.

scholarly journals Use of theoretical efficiencies of protein and fat synthesis to calculate energy requirements for growth in pigs

2008 ◽  
Vol 101 (6) ◽  
pp. 895-901 ◽  
Author(s):  
Carl Z. Roux
Keyword(s):  
Experimental Evidence ◽  
Heat Production ◽  
Energy Requirements ◽  
Regression Estimate ◽  
Retention Efficiency ◽  
Body Protein ◽  
Approximate Equality ◽  
Fat Synthesis ◽  
The Cost ◽  
Fasting Heat Production

From the observation that fasting heat production includes the cost of body protein resynthesis and the evidence that protein resynthesis is included in the regression estimate of protein retention efficiency it is conjectured that the estimate of maintenance from fasting heat production must be conceptually equal to the regression intercept estimate of maintenance plus the cost of body protein resynthesis. Experimental evidence for comparable situations shows an approximate observational equality in agreement with the conjectured conceptual equality. This approximate equality implies that the theoretical (stiochiometric) efficiency of protein synthesis should be used in conjunction with the estimate of maintenance from fasting heat production for the prediction of growth energy requirements. The approximate maintenance equalities suggest furthermore approximate equality of theoretical fat synthesis efficiency and regression fat retention efficiency. This conjecture is also supported by experimental evidence. Some practical nutrition and pig breeding implications of the foregoing conclusions are indicated.

Level of cottonseed meal but not frequency of feeding regulates whole-body protein synthesis and growth of sheep fed a roughage diet

2009 ◽  
Vol 49 (11) ◽  
pp. 1023
Author(s):  
L. P. Kahn ◽  
Somu B. N. Rao ◽  
J. V. Nolan
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Cottonseed Meal ◽  
Whole Body ◽  
Body Protein ◽  
Protein Supplements ◽  
Protein Retention ◽  
Medium Quality ◽  
Protein Rich

An incomplete factorial experiment was conducted to determine the effect of level and frequency of feeding of a protein-rich supplement on the growth and whole-body protein metabolism of young sheep fed a medium quality roughage diet. Cottonseed meal (CSM) was used as the protein supplement and provided at 0, 0.2 or 0.4% liveweight per day at a frequency of 1 or 3 times each week and chopped oaten (0.95) and lucerne (0.05) hay was the roughage. Growth rate more than doubled (P < 0.01) following provision of CSM but there was no advantage of feeding CSM at the highest level. Frequency of feeding CSM did not alter growth rate. Intake of hay was little affected by CSM and as a consequence the food conversion ratio declined (P < 0.01) favourably from 22 : 1 (nil CSM) to 9 : 1 as a result of supplementation. The rate of whole-body protein synthesis increased (P < 0.01) in response to the highest level of CSM with no apparent change in protein degradation, underpinning an increase (P < 0.01) in protein retention. These results highlight the role of protein supplements for promoting growth of young sheep on roughage diets and indicate that these supplements need to be provided only once a week.

Influence of protein intake on whole body and splanchnic leucine kinetics in humans

1997 ◽  
Vol 272 (4) ◽  
pp. E584-E591 ◽  
Author(s):  
M. Cayol ◽  
Y. Boirie ◽  
F. Rambourdin ◽  
J. Prugnaud ◽  
P. Gachon ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Intake ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
The Body ◽  
Whole Body ◽  
Body Protein ◽  
Leucine Kinetics ◽  
Protein X ◽  
Pool Model

The influence of the protein content of the meal on protein turnover was investigated in the splanchnic bed and in the remaining parts of the body in humans. Two groups of five subjects consumed every 20 min a liquid formula providing either 1.5 g protein x kg(-1) x day(-1) (P) or no protein (PF). L-[1-(13)C]leucine and L-[5,5,5-(2)H3]leucine were administered by vein and gut, respectively. An open two-pool model was developed to calculate leucine kinetics in both compartments, with the assumption that the enrichment of the tracers incorporated into very low density lipoprotein apolipoprotein B100 at isotopic steady state could reflect the leucine labeling in the splanchnic region. Nonsplanchnic uptake and release of leucine were not significantly different in the two groups. Within the splanchnic area, leucine uptake was 2.1 times higher in the P than in the PF group (P < 0.01), whereas leucine release was reduced but not significantly (-19%) in the P group compared with the PF group. Moreover, data derived from this model showed that protein intake induced an increase in whole body protein synthesis and no change in whole body protein breakdown. Albumin synthesis, as well as its contribution to whole body protein synthesis, was significantly enhanced by protein intake.

Compensatory growth in immature sheep: I. The effects of weight loss and realimentation on the whole body composition

1975 ◽  
Vol 85 (2) ◽  
pp. 193-204 ◽  
Author(s):  
K. R. Drew ◽  
J. T. Reid
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Body Fat ◽  
Good Predictor ◽  
Dry Matter ◽  
Body Water ◽  
The Body ◽  
Whole Body ◽  
Body Protein ◽  
Ad Libitum

SUMMARYForty-eight cross-bred wether lambs were used to measure the effects of severe feed restriction and realimentation on the body and carcass composition of immature sheep. Ten of the total number of sheep were used as an initial slaughter group, 12 were continuously fed (six at the ad libitum level of intake and six at 70% ad libitum), 26 were progressively underfed and 18 of them were realimented after a mean loss of about 25% empty body weight (EBW).Shrunk body weight (SBW = weight after an 18-h fast with access to water) was a good predictor of empty body weight (EBW = SBW minus gastro-intestinal contents) and the EBW of continuously growing sheep was a good predictor of body water, protein, fat, energy and ash, but it was not precise after realimentation, particularly in the early stages of refeeding. Restricted continuous supermaintenance feeding did not alter the body composition of the sheep from that of the sheep on the ad libitum intake at any given EBW except slightly to increase the carcass protein content.Although underfeeding to produce an EBW loss of 25% generally produced changes in the chemical body components which were similar to a reversal of normal growth, body fat did not decrease during the first half of the submaintenance feeding and did not increase during the first 2 weeks of realimentation. Under all circumstances percentage body fat was very closely related to percentage body water.Sheep realimented at 26 kg (after losing 25% EBW) contained, at 45 kg EBW, more bodywater and protein and less fat and energy than continuously-fed animals of the same EBW. The treatment effects were greater in the carcass and had little effect on the non-carcass EBW, with th e result that the refed sheep had 1800 g more water × protein in a carcass that weighed 700 g more than one from a normally grown sheep of the same EBW. The regression of calorific value of th e ash-free dry matter on body fat as a percentage of ash-free dry matter gave calorific values of body protein and fat as 5·652 and 9·342 kcal/g of ash-free dry matter, respectively.

A note on the effect of ageing on whole-body protein turn-over in goats

1988 ◽  
Vol 46 (3) ◽  
pp. 479-481 ◽  
Author(s):  
T. Muramatsu ◽  
Y. Ueda ◽  
T. Hirata ◽  
J. Okumura ◽  
I. Tasaki
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Mammalian Species ◽  
Weight Basis ◽  
Dynamic State ◽  
Whole Body ◽  
Body Protein ◽  
Turn Over

In ruminants a dynamic state of protein turn-over has been poorly understood although the methodology of measuring the rate of protein turn-over has recently been advanced to a great extent (Waterlow, Garlick and Millward, 1978). Available evidence suggests that ruminants such as sheep and cows are no exception among various mammalian species when whole-body protein synthesis of adult animals is compared on a metabolic body-weight basis (Waterlow et al., 1978; Reeds and Lobley, 1980).

scholarly journals 189 Efficiency of utilizing standardized ileal digestible Thr for whole body protein retention in pregnant gilts during early, mid and late gestation.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 303-303
Author(s):  
R Navales ◽  
J Dunn ◽  
J Htoo ◽  
K Touchette ◽  
R Thaler ◽  
...  
Keyword(s):  
Late Gestation ◽  
Whole Body ◽  
Body Protein ◽  
Protein Retention
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