The description of the rate of protein and lipid growth in pigs in relation to live weight

2002 ◽  
Vol 138 (4) ◽  
pp. 415-423 ◽  
Author(s):  
C. T. WHITTEMORE ◽  
D. M. GREEN

The paper seeks to compare the effectiveness of various functions as appropriate to express protein retention and lipid retention as a function of pig live weight. Linear descriptors were adequate for protein growth over the 20 to 120 kg live weight range, but not adequate when higher live weights were included. Linear descriptors were not adequate for lipid growth over any weight range. Quadratic and cubic polynomials, and the logistic function, were faulted on their failure to describe the known biology. Augmentation of the allometric function added nothing to the simple form. The Gompertz function was consistently effective for the description of daily protein retention rate. The Bridges and Richards functions are more flexible than the Gompertz with respect to the point of inflection, but when applied they resembled the Gompertz and therefore did not materially influence the descriptive outcome. The cubic polynomial, augmented allometric, Bridges and Richards functions, although favoured in other reports, were found to add nothing to the more simple functions. It is concluded that protein retention can be well expressed in relation to live weight by linear and Gompertz functions. Lipid retention could be well described by an allometric relationship with pig mass.

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)


1977 ◽  
Vol 25 (2) ◽  
pp. 255-258 ◽  
Author(s):  
A. N. Howard ◽  
W. C. Smith

SUMMARYIn an analysis of data from 211 litters in a Pietrain herd, litter size at birth and at weaning was lower than is generally found in indigenous breeds. Mortality in growing and breeding pigs was high with circulatory failure accounting for 23% and 95% of deaths respectively. Pietrains, fed ad libitum over the live-weight range 27 to 87 kg, grew more slowly by 130 g/day than contemporary Large Whites on the same feeding regime, had higher killing-out percentages (by 3 to 4 units) and larger eye muscles in cross-section (by 9·9 cm2) but tended to have higher feed conversion ratios. There was no breed difference in backfat measurements but Pietrain carcasses were shorter by 83 mm and their muscle quality was markedly inferior to that of the Large Whites.


2009 ◽  
Vol 193 ◽  
pp. 95-110 ◽  
Author(s):  
Giorgio Ottaviani

AbstractWe compute the equation of the 7-secant variety to the Veronese variety (P4,O(3)), its degree is 15. This is the last missing invariant in the Alexander-Hirschowitz classification. It gives the condition to express a homogeneous cubic polynomial in 5 variables as the sum of 7 cubes (Waring problem). The interesting side in the construction is that it comes from the determinant of a matrix of order 45 with linear entries, which is a cube. The same technique allows to express the classical Aronhold invariant of plane cubics as a pfaffian.


1980 ◽  
Vol 31 (2) ◽  
pp. 221-222 ◽  
Author(s):  
R. D. H. Cohen ◽  
D. L. Garden ◽  
J. P. Langlands

ABSTRACTThe incidence of oestrus in 603 Hereford heifers with a mean age of 545 days (range 515 to 575) was related to live weight (range 130 to 376 kg). Observations were ranked in order of ascending live weight and the percentage of heifers showing oestrus was calculated for consecutive 10 kg increments in live weight from 130 to 380 kg. The percentage showing oestrus was subjected to the probit transformation (Y, probit units) and was then related to live weight (X, kg):It was predicted that 50% of the heifers showed oestrus at 231 ± 1 kg, and that 5% and 95% showed oestrus at 187 and 280 kg respectively.


2020 ◽  
Vol 8 (4) ◽  
pp. 994-1010
Author(s):  
Weizhi Xu

This paper investigates one kind of interpolation for scattered data by bi-cubic polynomial natural spline, in which the integral of square of partial derivative of two orders to x and to y for the interpolating function is minimal (with natural boundary conditions). Firstly, bi-cubic polynomial natural spline interpolations with four kinds of boundary conditions are studied. By the spline function methods of Hilbert space, their solutions are constructed as the sum of bi-linear polynomials and piecewise bi-cubic polynomials. Some properties of the solutions are also studied. In fact, bi-cubic natural spline interpolation on a rectangular domain is a generalization of the cubic natural spline interpolation on an interval. Secondly, based on bi-cubic polynomial natural spline interpolations of four kinds of boundary conditions, and using partition of unity technique, a Partition of Unity Interpolation Element Method (PUIEM) for fitting scattered data is proposed. Numerical experiments show that the PUIEM is adaptive and outperforms state-of-the-art competitions, such as the thin plate spline interpolation and the bi-cubic polynomial natural spline interpolations for scattered data.


1968 ◽  
Vol 64 (3) ◽  
pp. 655-658 ◽  
Author(s):  
K. McCann ◽  
K. S. Williams

Some recent work by the authors (1) on the distribution of the residues of a cubic polynomial modulo an odd prime p led to the conjecture that, in general, two cubic polynomials with integer coefficients possessing the same residues modulo p (not necessarily occurring to the same multiplicity) are equivalent, that is are related by a linear transformation modulo p. The purpose of the present paper is to prove this conjecture. We establish the following theorem.


1978 ◽  
Vol 27 (2) ◽  
pp. 181-189 ◽  
Author(s):  
E. Hind

ABSTRACT1. Eight-one British Friesian and 44 Jersey steers was slaughtered at 1. 12, 24, 48 or 72 weeks of age. Those aged 24 weeks and over were reared on a standard complete diet offered ad libitum, and individual food intakes were recorded until slaughter when carcasses were dissected on an anatomical basis.2. From 1 to 72 weeks British Friesians were on average 50% heavier than Jerseys and consumed 47% more food. Total lean tissue (L) increased 11-fold to 137 + 6·4 kg in the British Friesians and 16-fold to 84 ± 4·7 kg in the Jersey. L as a percentage of live weight rose to 32% ±0·6 in the British Friesians and to 29% ±0·8 in the Jerseys. Breeds did not differ significantly in average efficiency of growth of lean tissue in any period.3. From 24 to 72 weeks, an allometric relationship held between L and total food consumed postnatally, F. The two breeds had the same allometric coefficient of 0·61. Current efficiency, 0·61 L/F, was thus proportional to cumulated efficiency, L/F. Allowance was made for the prenatal input, Fo, required to produce the newborn calf. An optimum slaughter point at which overall efficiency, L/(F+F0), reached a maximum occurred in each breed when postnatal input was 58% higher than prenatal input (F = 1·58F0). When the breeds had equal maximum efficiency the British Friesian: Jersey ratios for prenatal input, total food consumed and total lean produced were all 2·6:1.


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.


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.


1993 ◽  
Vol 57 (2) ◽  
pp. 253-261 ◽  
Author(s):  
J. E. Vipond ◽  
G. Swift ◽  
R. C. Noble ◽  
G. Horgan

AbstractThe effect of grazing clover on ewes and lambs was studied using nitrogen-fertilized grass (G) and grass/white clover pastures (GC) containing proportionately 0·18 clover. Carcasses of lambs grazed on GC were significantly heavier than carcasses of lambs grazed on G pastures. An interaction with weaning occurred. Carcasses from lambs grazed on GC for 53 days post weaning were 2·3 kg heavier (F < 0·01) but lambs slaughtered at weaning had similar carcass weights. Diet had no effect on relative joint components of carcasses. The effect of clover in the diet on carcass weight was attributed to higher levels of protein retention.Analysis of the fatty acid composition of intramuscular and subcutaneous and perirenal lipids indicated small but significant effects of diet. Lean tissue lipids of lambs grazing clover showed significant increases in C18:2 and reduced C20: 5 fatty acids. In tissue fats there were small increases in C14:0, C16:0 and C18:2 with reduced C18:1 content.Twin suckled lambs grazing GC for 94 days from turn-out in early April showed increased live-weight gain over lambs on G of 336 v. 287 g/day (s.e.d. 84; P < 0.001). Post weaning live-weight gain of lambs was 173 and 221 g/day on G and GC respectively. Sward height was maintained at 5.18 and 5.24 (s.e.d. 0.075) cm on G and GC paddocks by adjusting ewe numbers. GC pastures carried proportionately 0.82 of the stock on G pastures but output of lamb was similar at 1289 and 1247 kg/ha for G and GC respectively.Results showed that the production penalty of lower stocking rate associated with grass/clover v. grass fertilized with 190 kg nitrogen per ha was ameliorated by higher lamb live-weight gain and carcass weight without change in joint composition or nutritionally significant change in fatty acid composition of carcass tissues.


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