scholarly journals Effect of essential:total nitrogen ratio on protein utilization in the growing pig

1998 ◽  
Vol 80 (6) ◽  
pp. 537-544 ◽  
Author(s):  
Jaroslav Heger ◽  
Samson Mengesha ◽  
David Vodehnal
Keyword(s):  
Amino Acids ◽  
Essential Amino Acids ◽  
Growing Pigs ◽  
Protein Utilization ◽  
Total N ◽  
N Retention ◽  
Growing Pig ◽  
N Utilization ◽  
Nitrogen Ratio ◽  
Crystalline Amino Acids

Two N balance experiments using growing pigs were conducted to study the effect of essential:total (E:T) N ratio on N retention and utilization. Purified diets contained casein and crystalline amino acids as the sole sources of N. E:T values ranged from 0·25 to 0·86 while either the concentration of total N (Expt. 1) or essential N (Expt 2) was kept constant. At a constant concentration of total dietary N, N retention and total N utilization were maximized with an E:T value of approximately 0·6, while essential N utilization gradually decreased as E:T increased. At a constant level of essential N, N retention remained unchanged until the E:T value reached 0·48 and then decreased. In Expt 2, maximum total N utilization was attained with an E:T value of 0·66 while N excretion and essential N utilization decreased with increased E:T value. These results suggest that under conditions of optimal protein utilization, essential amino acids are partially degraded and used for the synthesis of non-essential amino acids.

scholarly journals Evaluation of undehydrated barley feed fractions and dried oat feed fractions from integrated starch-ethanol process in diets of growing pigs

1992 ◽  
Vol 1 (3) ◽  
pp. 291-301 ◽  
Author(s):  
Matti Näsi ◽  
Erkki Aimonen
Keyword(s):  
Latin Square ◽  
Protein Digestibility ◽  
Essential Amino Acids ◽  
Nutrient Digestibility ◽  
Growing Pigs ◽  
Ether Extract ◽  
Protein Utilization ◽  
N Retention ◽  
Extract Content ◽  
Protein Supply

The nutrient digestibility and protein utilization of undehydrated barley fractions: protein (BP), protein fibre mixture (BPF) and distillers solids (DS) at two levels of inclusion in diets fortified to equal lysine content were assayed with growing pigs in a 6 x 6 Latin square. Dried barley fibre (BF), oat protein (OP) and oat fibre (OF) from integrated starch-ethanol production were evaluated as feed ingredients for pigs in three other trials. DS and OP had a higher essential amino acids content than BP, especially with respect to lysine. All fractions had a rather high ether extract content 46-196 g/kg and their fatty acid composition is presented. BP showed higher protein digestibility than DS (0.931 vs. 0.857) and pigs on BP-diet retained more N than on DS-diet. BF showed a low digestibility of OM and CP and 0.1 inclusion of BF mixed with BP depressed CP digestibility and N-retention. A higher protein supply from cereal protein in the diet promoted N-retention but decreased protein utilization. OP had high digestibility and OF was more digestible than BF. The study confirmed the high digestibility and energy values of the proteinous grain fractions and a high protein utilization when adequately fortified with lysine. The fibrous fractions have a rather low nutrient digestibility and their use in pig diets is therefore limited.

scholarly journals The optimum dietary amino acid pattern for growing pigs

1989 ◽  
Vol 62 (1) ◽  
pp. 77-89 ◽  
Author(s):  
T. C. Wang ◽  
M. F. Fuller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Agricultural Research ◽  
Essential Amino Acids ◽  
Growing Pigs ◽  
Amino Acid Pattern ◽  
Single Amino Acid ◽  
N Retention ◽  
Dietary Amino Acid ◽  
Optimum Balance

A series of four nitrogen-balance experiments was carried out with growing pigs to determine the optimum balance amongst the amino acids in the diet. The reduction in N retention when 20 % of a single amino acid was removed from the diet was used to calculate a dietary amino acid pattern in which each amino acid would he equally limiting. A mixture of amino acids simulating the amino acid pattern of casein was used with the same efficiency as casein. From two successive deletion experiments an optimum balance amongst the essential amino acids was derived. Expressed relative to lysine = 100 this had threonine 72, valine 75, methionine + cystine 63, isoleucine 60, leucine 110, phenylalanine + tryosine 120, tryptophan 18. No estimate was made for histidine. Essential amino acids in this pattern were mixed with non-essential amino acids in ratios of 36:64 up to 57:43. The highest efficiency of N retention was achieved with diets having a ratio of at least 45:55. This included (g/16 g N) lysine 6 5, threonine 4.7, valine 4 9, methionine + cystine 4.1, isoleucine 3 9, leucine 7.2, phenylalanine + tyrosine 7.8, tryptophan 12. The N of diets with this amino acid pattern was utilized significantly better than when the pattern proposed by the Agricultural Research Council (1981) was used. The flow of amino acids past the terminal ileum of pigs given the semi-synthetic diet with this amino acid pattern was no greater than that observed with protein-free diets. The proposed pattern thus describes the intrinsic requirements of the growing pig for absorbed amino acids.

scholarly journals Utilization of dried microbial cells grown on methanol in a semi-purified diet for growing pigs

1976 ◽  
Vol 36 (3) ◽  
pp. 403-410 ◽  
Author(s):  
J. P. F. D'Mello ◽  
D. G. Peers ◽  
C. T. Whittemore
Keyword(s):  
Amino Acids ◽  
Growing Pigs ◽  
Total N ◽  
Microbial Cells ◽  
Nitrogenous Compounds ◽  
Fresh Food ◽  
N Utilization ◽  
True Digestibility ◽  
Protein Free Diet ◽  
Net Protein

1. Twenty-four pigs (mean body-weight 44 kg) were used to determine the digestibilities of energy, nitrogen and amino acids in dried microbial cells (DMC) grown on methanol and in white fish meal (WFM). N utilization and the excretion of various nitrogenous compounds were also studied.2. Semi-purified diets containing DMC, WFM or no protein source were offered at the rate of 1 kg fresh food/d. Daily N intakes were 26.5, 24.7 and 0.65 g respectively.3. Mean metabolic faecal N determined with the protein-free diet was 1.11 g/d (1.26 g/kg dry matter (dm) eaten) for the two experiments. The corresponding endogenous urinary N value was 2.91 g/d.4. Daily urinary N output of pigs given the diet with WFM was significantly greater than that of pigs given the diet with DMC, with the result that N retention, net protein utilization and biological value were higher for pigs given DMC.5. Apparent and true digestibility of amino acids were higher for the diet with DMC than for the diet with WFM.6. N excretion in the form of ammonia, urea, uric acid and allantoin accounted for 81, 91 and 99% of the total N excreted by the groups given the protein-free diet, DMC and WFM respectively. Pigs given DMC excreted greater quantities of allantoin-N and less urea-N than pigs given WFM.

An optimal dietary amino acid pattern for growing pigs

1997 ◽  
Vol 1987 ◽  
pp. 91-91 ◽  
Author(s):  
T. C. Wang ◽  
M. F. Fuller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Retention ◽  
Essential Amino Acids ◽  
Growing Pigs ◽  
Amino Acid Pattern ◽  
Dietary Amino Acid ◽  
Ideal Protein ◽  
Limiting Amino Acid ◽  
The Ideal

An animal's rate of protein accretion (or nitrogen retention) is determined by the most deficient (or first limiting) amino acid in the diet, in a perfectly balanced (or ideal) protein all essential amino acids and the sum of the non-essential amino acids are equally limiting. If a dietary protein had any amino acids in excess of the ideal pattern, then the removal of any of the excess should not affect nitrogen retention. This principle was used to determine the ideal dietary amino acid pattern for growing pigs.Three nitrogen balance trials were carried out with a total of 64 gilts of weight from 30 to 55 kg. Casein and a mixture of amino acids were used in the semi-purified diets. The animals were given the diets at the rate of 93 g/kg BW0.75/d in three equal meals mixed with 0.3 L water. The feeding times were 08.30, 12.30 and 17.30. All pigs received their experimental diets for 7 days, made up of 3 days preliminary and a 4-day collection, except that the preliminary period before the first collection in the first period was 7 days. Before the first collection bladder catheters were introduced.

scholarly journals The effect of heat on amino acids for growing pigs

1994 ◽  
Vol 72 (2) ◽  
pp. 243-256 ◽  
Author(s):  
R. J. Van Barneveld ◽  
E. S. Batterham ◽  
B. W. Norton
Keyword(s):  
Amino Acids ◽  
Crude Protein ◽  
Growing Pigs ◽  
Quadratic Effect ◽  
Ileal Digestibility ◽  
Protein Deposition ◽  
Growing Pig ◽  
Field Peas ◽  
Forced Air ◽  
Growth Experiments

Two growth experiments were conducted to determine the effect of heat on the utilization of ileal-digestible lysine from field peas (Pisum sativum cultivar Dundale) fed to growing pigs. Five lysine-deficient diets (0.36 g ileal-digestible lysine/MJ digestible energy (DE)) were formulated using raw field peas, and field peas heated to either 110°, 135°, 150°, or 165° for 15 min respectively in a forced-air dehydrator. Additional diets were formulated with supplements of free lysine to verify that lysine was limiting in the diets containing the raw peas, and peas heated to 150° or 165°. The growth performance and retention of ileal-digestible lysine by pigs given the diets was determined over the 20–45 kg growth phase. Heat had a significant quadratic effect (P < 0.01) on growth rate, with responses declining from 543 g/d with pigs given the raw peas, to 407 g/d for those given the peas heated to 165°. Similarly, crude protein deposition declined in a quadratic manner (P < 0.001) from 76 to 36 g/d for pigs fed on raw peas and peas heated to 165° respectively. Retention of ileal-digestible lysine was 0.85 in the pigs given the raw field peas and declined in a quadratic manner (P < 0.001) with the application of heat to 0.48 in those pigs given the peas heated to 165°. Pigs fed on field peas heated to 165° had increased (P < 0.05) liver weights. The results indicate that heat applied to protein concentrates, even at mild temperatures, renders lysine in a form that is apparently absorbed but inefficiently utilized by the growing pig. Consequently, ileal digestibility values for lysine in heat-processed meals are unsuitable for diet formulations.

scholarly journals 46 How far we could go reducing crude protein with the use of supplemental amino acids

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 22-23
Author(s):  
Candido Pomar
Keyword(s):  
Amino Acids ◽  
Dietary Protein ◽  
Optimal Growth ◽  
Essential Amino Acids ◽  
Growing Pigs ◽  
Growth Stages ◽  
Body Protein ◽  
Low Protein ◽  
Maintenance Requirements ◽  
Protein Reduction

Abstract Feeding growing pigs with diets providing the required amount of essential and non-essential amino acids (AA) reduces energy expenditure and minimizes N excretion. Low protein diets can be obtained by supplementing feeds with crystalline AA. Numerous experiments have evaluated the ideal dietary AA concentration at different growth stages, but reducing dietary protein with the use of supplemental AA is limited by the inaccuracy of the principles used to estimate AA requirements. One of these principles states that growing animals need AA for maintenance and growth. Maintenance requirements are related to BW whereas the efficiency of AA utilization (e.g., 72% for Lys) and body protein AA composition are constant (e.g., 7% for Lys). These parameters are, however, affected by AA restriction, meal frequency, energy supply, genetics, etc. Even when controlling these factors, individual pigs respond differently to the same AA supply. Yet pigs are raised in groups and fed with a unique feed for long periods. Individual pigs within a given population differ in terms of BW, ADG, health status, etc., and consequently, differ in the amount of AA they need at a given time. Therefore, when feeding a group of pigs, the concept of maintenance and growth requirements may not be appropriate. In this situation, nutrient requirements should be seen as the optimal balance between the proportion of animals that needs to be overfed and underfed. Given that for most AA, underfed animals exhibit reduced performance, whereas overfed animals exhibit near-optimal performance, optimal growth is obtained when nutrients are provided to satisfy the requirements of the most demanding animals. There is therefore a trade-off between performance and dietary protein reduction. The inaccuracy of the principles used to estimate AA requirements, both for individual animals and populations, limits how far we can go reducing dietary protein with the use of supplemental AA.

Optimum dietary amino acid pattern and limiting order of some essential amino acids for growing-furring blue foxes (Alopex lagopus)

2004 ◽  
Vol 78 (1) ◽  
pp. 77-86 ◽  
Author(s):  
T. Dahlman ◽  
J. Valaja ◽  
E. Venäläinen ◽  
T. Jalava ◽  
I. Pölönen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Control Diet ◽  
Essential Amino Acids ◽  
Amino Acid Pattern ◽  
N Retention ◽  
Low Protein ◽  
Acid Control ◽  
Blue Fox ◽  
Limiting Amino Acid

AbstractThe optimum pattern and limiting order of some essential amino acids for growing-furring blue foxes were assessed from nitrogen (N) retention responses. Total tract digestibility and N balance trials were carried out on 24 weaned blue fox males in an 8 ✕ 5 cyclic change-over experiment. Eight experimental diets were prepared by removing proportionately about 0·4 of each of the amino acids studied – methionine + cystine, lysine, threonine, tryptophan and histidine – successively from the amino acid control diet. The main source of protein in the amino acid control diet was casein and an amino acid mixture was added to bring the calculated crude protein (CP) content up to the level of 170 g/kg dry matter (DM). Low-protein (CP 95·7 g/kg DM) and high-protein (CP 166·6 g/kg DM) diets, the protein proportion of which was casein protein, served as negative and positive control diets, respectively. The reduction in N retention when one amino acid in turn was deleted from the amino acid control diet was calculated, and a regression analysis was made between N retention and relative amino acid intake. Data on the animals’ intake of each limiting amino acid and those on the amino acid control diet were used. The optimum amino acid pattern, expressed relative to lysine = 100, proved to be: methionine + cystine 77, threonine 64, histidine 55 and tryptophan 22. The first-limiting amino acids were methionine + cystine. Blue fox responses (N retention, weight gain) to deletion of methionine + cystine from the diet were very severe and exceeded those to deletion of any other amino acid. Moreover, removing methionine + cystine from the diet significantly impaired the apparent digestibility of organic matter, reducing it to a level even lower than that of the low-protein diet. After methionine + cystine, the next-limiting amino acid in casein-based diets was threonine, followed by histidine and tryptophan. The results show the importance of verifying the sufficiency of dietary methionine + cystine in the practical feeding of blue foxes.

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