scholarly journals Partitioning of limiting protein and energy in the growing pig: testing quantitative rules against experimental data

2005 ◽  
Vol 93 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Fredrik B. Sandberg ◽  
Gerry C. Emmans ◽  
Ilias Kyriazakis

Literature solutions to the problem of protein and energy partitioning in the growing pig are quantitatively examined. Possible effects of live weight, genotype and food composition on the marginal response in protein retention to protein and energy intakes, on protein and energy-limiting foods are quantified. No evidence was found that the marginal response in protein retention to ideal protein supply, when protein intake is limiting, is affected by live weight, genotype or environmental temperature. There was good evidence that live weight does not affect the marginal response in protein retention to energy intake when protein intake is not limiting. Limited data for different genotypes suggested no effects on this response. A general quantitative partitioning rule is proposed that has two key parameters;ep* (the maximum marginal efficiency for retaining the first limiting amino acid) andR* (the maximum value ofR, the energy to protein ratio of the food, MJ metabolisable energy (ME)/kg digestible crude protein (DCP), whenep* is just achieved). WhenR<R* the material efficiency of using ideal protein is (ep*/R*)×R. The value ofep* was determined to be 0·763 (se 0·0130). There was no good experimental evidence thatep* is different for different amino acids. The best estimate ofR* was 67·9 (se 1·65) MJ ME/kg DCP. Live weight, genotype and temperature did not affect the values of either parameter. A more general understanding of partitioning, including the effects of ‘stressors’ such as disease, may be achieved by using the preferred rule as a starting point.

2005 ◽  
Vol 93 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fredrik B. Sandberg ◽  
Gerry C. Emmans ◽  
Ilias Kyriazakis

A core part of any animal growth model is how it predicts the partitioning of dietary protein and energy to protein and lipid retention for different genotypes at different degrees of maturity. Rules of partitioning need to be combined with protein and energy systems to make predictions. The animal needs describing in relation to its genotype, live weight and, possibly, body composition. Some existing partitioning rules will apply over rather narrow ranges of food composition, animal and environment. Ideally, a rule would apply over the whole of the possible experimental space (scope). The live weight range over which it will apply should at least extend beyond the ‘slaughter weight range’, and ideally would include the period from the start of feeding through to maturity. Solutions proposed in the literature to the partitioning problem are described in detail and criticised in relation to their scope, generality and economy of parameters. They all raise the issue, at least implicitly, of the factors that affect the net marginal efficiency of using absorbed dietary protein for protein retention. This is identified as the crucial problem to solve. A problem identified as important is whether the effects of animal and food composition variables are independent of each other or not. Of the rules in the literature, several could be rejected on qualitative grounds. Those rules that survived were taken forward for further critical and quantitative analysis in the companion paper. (Sandberget al.2005)


1983 ◽  
Vol 50 (3) ◽  
pp. 605-617 ◽  
Author(s):  
R. G. Campbell ◽  
A. C. Dunkin

1. The effects of feeding either a high-protein (HP) diet or a low-protein (LP) diet between 1·8 and 15 kg live weight (LW) and a low-energy (LE) or a high-energy (HE) intake but at the same protein intake subsequent to 15 kg LW on the performance and body composition of pigs growing to 75 kg LW were investigated.2. During the LW period 1·8–15 kg, pigs given the LP diet exhibited poorer growth performance (P < 0·01) and at 15 kg contained more fat (P < 0·01) in their empty bodies than pigs given the HP diet.3. On the LE treatment subsequent to 15 kg LW, pigs previously given the LP diet deposited protein at a faster rate and exhibited more rapid and efficient growth to 60 kg LW than those given the HP diet before 15 kg. However, on the HE treatment, pigs previously given the LP diet deposited protein at a slower rate and exhibited poorer growth performance (P < 0·05) between 15 and 45 kg LW but grew at a faster rate between 45 and 60 kg LW than pigs previously given the HP diet.4. On the LE treatment subsequent to 15 kg LW the differences in body composition between the two protein groups were no longer significant at 45 kg. However, on the HE treatment, pigs previously given the LP diet remained fatter (P < 0·05) to 60 kg LW than those previously given the HP diet.5. The results suggested that restricting protein intake between 1.8 and 15 kg LW reduced, temporarily, the upper limit of protein retention and growth performance during subsequent development. This finding is discussed in relation to the effects of protein nutrition in early life on the hyperplasic development of muscle tissue.


2002 ◽  
Vol 2002 ◽  
pp. 26-26
Author(s):  
D. M. Green ◽  
C. T. Whittemore

The proposed model may be considered as an advance upon previous models; giving a synthesis of the contemporary information base and having a structure with maximum flexibility and minimum usage of fixed coefficients. It is distinctive in that it includes: (1) linkage from dietary nutrients to tissue retention via algorithms for main-stream biochemical processes; (2) a unified driver allowing compatible calculation of (i) the nutrient costs of energy and of protein cycling, (ii) the nutrient costs of maintenance and protein retention, and (iii) the interactions between energy and protein usage; (3) prediction of the rate and composition of tissue retention during growth, and of the cost of thermoregulation; (4) reversal of the role of conventional model parameters such that they become out-turns, rather than inputs, of the model, including (i) the metabolisability of energy, (ii) the ideality of protein and the efficiency of use of ileal digested ideal protein, (iii) the efficiency of utilisation of energy (k) for maintenance (kM), for protein (kPr) and lipid (kLr) retention, which are accepted as variables derived from calculation of efficiencies of production of ATP.


1984 ◽  
Vol 18 (1) ◽  
pp. 75-80 ◽  
Author(s):  
A. López ◽  
C. García

A 3 × 3 factorial experiment was carried out, in which natural ingredient diets formulated at 3 digestible energy levels (DE) (100, 90 and 80% of NRC, 1978 recommendations) and at 3 energy: protein ratios (EPR) (63, 71 and 79 kJ DE/g crude protein (CP)) were fed to 8 weanling male Wistar rats/group. Half of these animals were sacrificed at the end of the 6-week experimental period and their body composition analyzed. Retentions of protein and energy were assessed by difference from a similar group of 8 rats killed and analyzed at the beginning of the experiment. No interaction was found between the 2 factors studied. Main results showed a decrease in intake and retention of both energy and protein, without affecting the efficiency of retention when energy level of diets was reduced by 20%. An increase in the EPR of the diets led to a decrease in protein intake and to an increase in efficiency of protein retention, without affecting the amount retained. No changes in body composition, nor in composition of live weight gains were found as a result of treatments. It is concluded that a 10% reduction in DE level of the diet is of no consequence, and that an EPR of 79 kJ/g leads to more efficient use of the dietary protein without detrimental effects over any other nutritional indicator.


1992 ◽  
Vol 68 (3) ◽  
pp. 615-625 ◽  
Author(s):  
I. Kyriazakis ◽  
G. C. Emmans

The objective of the experiment was to define the form of the relationship between varying levels of protein and energy intake and the performance of young pigs. Forty-four young pigs were assigned at 12 kg live weight for 6 weeks either to an initial slaughter group (n 8) or to one of the nine feeding treatments (n 4); three allowances of a high-protein food with 355 g crude protein (nitrogen × 6.25; CP)/kg (P1, P2, P3) at three levels of feeding (L, M and H). Each feeding level was met by supplementing the allowance of feed P with the appropriate amount of starch and each treatment had two males and two females. The rate of protein deposition was not affected by feeding level at the two lowest allowances of basal feed P (P1 and P2), but it increased with increasing the feeding level for the pigs on treatment P3. Males deposited more protein than females, but this effect was more pronounced with treatment P3. The rate of lipid deposition increased with each increase in the level of feeding and decreased with increasing the allowance of feed P. The calculated efficiency of protein utilization (ep) was expressed as a function of the energy: protein ratio in the feed (MJ metabolizable energy/kg digestible CP). The best model to describe the relationship was a linear-plateau model, with the maximum value for ep of 0.814 at 73 MJ/kg. This relationship provided the basis of a model that could predict the response of a growing pig to its diet as rates of protein and lipid retention


1991 ◽  
Vol 53 (3) ◽  
pp. 383-393 ◽  
Author(s):  
S. A. Beech ◽  
R. Elliott ◽  
E. S. Batterham

AbstractThe effects of dietary sucrose, glucose and starch were compared to determine whether sucrose as an energy source affected energy or protein metabolism of growing pigs given food either frequently or once daily. Three experiments were conducted using three diets (0·8 g lysine per MJ digestible energy (DE)) containing sucrose, starch or glucose, respectively. In the first experiment, the DE contents of the diets were determined. In the second, the diets were given either once daily (08.00 h) or frequently (3-h intervals) to growing pigs (20 to 45 kg live weight) and growth responses, blood characteristics and energy, protein and fat retention measured. In the third experiment, the three diets were given to seven pigs (50 kg live weight), either once daily or frequently to monitor further the effects on plasma triglycerides, glucose, urea and insulin levels.Growth rate, on a carcass basis, was slightly lower in pigs given glucose relative to starch (P < 0·05) but there was no effect of carbohydrate source on the retention of energy, protein or fat. Plasma triglyceride levels were lower in pigs given starch (P < 0·05) whilst plasma glucose and insulin concentrations were higher immediately after feeding in pigs given food once daily (7 < 0·05, P < 0·01). All three carbohydrate sources were used less efficiently by the pigs for energy, protein and fat deposition with once daily compared with frequent feeding (V < 0·01). Overall, these results indicate that sucrose as an energy source does not effect energy or protein metabolism by the growing pig. It appears that the metabolism of fructose within sucrose had no effect on metabolism.


1972 ◽  
Vol 14 (1) ◽  
pp. 47-55 ◽  
Author(s):  
G. A. Lodge ◽  
M. E. Cundy ◽  
R. Cooke ◽  
D. Lewis

SUMMARYForty-eight gilts by Landrace sires on Large White × Landrace females were randomly allocated to eight pens and within pens to six treatment groups involving three diets and two levels of feeding from 23 to 59 kg live weight. All diets were formulated to have approximately the same ratio of digestible energy to crude protein (160 kcal DE/unit % CP) but different energy and protein concentrations: (A) 3500 kcal/kg DE and 21 % CP, (B) 3150 kcal/kg DE and 19% CP, and (C) 2800 kcal/kg DE and 17% CP. Amino acid balance was maintained relatively constant with synthetic lysine, methionine and tryptophan. The levels of feeding were such that the lower level of diet A allowed an intake of energy and protein similar to the higher level of diet B, and the lower level of B was similar to the higher level of C.On the lower level of feeding, growth rate, efficiency of feed conversion and carcass fat content increased linearly with each increment in nutrient concentration; on the higher level of feeding growth rate and EFC increased from diet C to B but not from B to A, whereas carcass fat content increased linearly with diet from the lowest to the highest concentration. There was a non-significant tendency for the higher density diets at a similar level of nutrient intake to give better EFC and fatter carcasses than the lower density diets.


2021 ◽  
Vol 28 (2) ◽  
pp. 187-192
Author(s):  
F. OLALERU ◽  
T. A. ADEGBOLA

The effects of cotton seed cake (CSC) or urea in supplying either 12% or 16% crude protein on sorghum stover utilization by Yankasa rams was studied for twelve weeks, using a 2 x 2 factorially designed experiment. Nutrient intake, digestibility, weight gain and feed conversion ratio (FCR) were monitored. In vitro volatile fatty acid (VFA) and ammonia-nitrogen (NH,-N) concentrations were also determined. The result of the study indicated that the source and/or level of nitrogen (or crude protein) significantly (P<0.05) affected crude protein intake (CPI), digestible crude protein intake (DCPI) and in vitro NH,-N concentration. Total feed intake, live weight gain (LWG), FCR and DCPI were significantly (P<0.05) affected by source x level interaction. Acid detergent fibre (A DF) and neutral detergent fibre (NDF) intakes, CP, ADF and NDF digestibilities, digestible ADF and NDF intakes, stover intake and in vitro VFA concentration were not significantly (P>0.05) affected by either main effects of CP source and level or their interaction. The rams on the 16% CSC and 12% urea ration gained more weight and had lower FCR than those on the 12% CSC and 16% urea. The 16% CSC ration gave the best result in terms of sorghum stover supplementation. The 12% urea treatment which also had a good result in terms of weight gain and FCR could also be recommended for use.


Author(s):  
D Dotas ◽  
I Kyriazakis ◽  
D H Anderson ◽  
G C Emmans

It has been suggested (Kyriazakis and Emmans, 1992a, b) that the material efficiency with which the pig can retain protein (ep), is directly proportional to the energy:protein ratio of the diet (R), so that ep = k.R. This hypothesis accounts for the finding that the rate of protein deposition can sometimes be increased by increasing the energy supply at a constant rate of protein supply.It is also possible that the constant of proportionality, k, is a genetic variable, although it was proposed, partly for the sake of simplicity, that there would be no genetic effects on the value of k. To test the propositions: (i) that ep is proportional to R, and (ii) that k does not differ between genotypes, an experiment was designed and carried out on two pig breeds which were expected to be very different from each other.


1984 ◽  
Vol 38 (2) ◽  
pp. 233-240 ◽  
Author(s):  
R. G. Campbell ◽  
M. R. Taverner ◽  
D. M. Curic

ABSTRACT1. Eight diets of similar energy content, ranging in crude protein concentration from 95 to 256 g/kg, were given at either 2·5 or 3·2 times the energy level for maintenance to entire male pigs growing from 45 to 90 kg live weight.2. Growth rate improved with increase in feeding level and with increasing dietary crude protein up to 164 g/kg (P < 0·05). The food conversion ratio improved with each increase in dietary CP up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05). It was also improved with increase in level of feeding of the lower-protein diets but deteriorated with increase in level of intake of the higher-protein diets (P < 005).3. Rate of protein deposition improved with increasing dietary crude protein up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 005). The results showed that, for pigs given diets deficient in crude protein, rate of protein deposition was linearly related to protein intake (P < 0·001) but independent of energy intake. For pigs given a diet adequate in crude protein, rate of protein deposition was related to energy intake and independent of crude protein intake.4. Body fat content at 90 kg decreased with increasing dietary crude protein up to 210 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05), and was increased by raising the level of intake of the higher-crude protein diets (P < 0·05). However, the influence of feeding level on body fat diminished as dietary crude protein was reduced.


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