+ All Categories
Home > Documents > AJINOMOTO 2013 Ideal Amino Acid Profile for Piglets

AJINOMOTO 2013 Ideal Amino Acid Profile for Piglets

Date post: 28-Dec-2015
Category:
Upload: freddy-alexander-horna-morillo
View: 49 times
Download: 3 times
Share this document with a friend
Popular Tags:
28
GO TO ESSENTIALS ® by Ideal Amino Acid Profile For Piglets October 2013
Transcript

G O T O E S S E N T I A L S ®

by

Ideal Amino Acid ProfileFor Piglets

October 2013

Table of Contents

Preface ........................................................................................................................... 3

Amino Acids in Pig Nutrition ....................................................................... 4Nutritional Systems ............................................................................................. 5Methodology ............................................................................................................. 6Tryptophan .................................................................................................................. 8Valine ............................................................................................................................. 10Isoleucine .................................................................................................................. 13Leucine ........................................................................................................................ 15Histidine ...................................................................................................................... 16Phenylalanine and Tyrosine ....................................................................... 17Ideal Amino Acid Profile ............................................................................... 18Low Crude Protein Diets ............................................................................. 20

Conclusion ............................................................................................................... 22References ............................................................................................................... 23

Ideal Amino Acid ProfileFor Piglets

ajinomoto eurolysine s.a.s. | 3

Recent advances and update of the amino acids profile for piglets

The increasing availability of crystalline amino acids (AA), as L-Tryptophan and L-Valine, has definitely changed the piglet feed structure and the way to deal with the nitrogen nutrition issue for these animals. Recently, the availability of L-Valine has been a breakthrough in feed formulation since it allows to match the requirement of this strong limiting AA, and to efficiently move from a formulation based on dietary crude protein (CP) to a formulation based on each essential AA. This increasing practice all over Europe results in a drastic decrease of the dietary CP levels and is the insurance to supply a feed in which AA needs are met with a high degree of precision. This technic enables the improvement of nitrogen efficiency while maintaining the performance of pigs. In these formulas, 7 AA are co-limiting and the dietary AA profile reaches an optimal balance to optimize the growth performance and the economic value of the feed.

Implementing an optimized AA nutrition needs prerequisites on the knowledge of AA requirements. Getting this information is crucial to answer the animal need but also to determine what the limiting AA in each particular situation is. The most limiting AA in a diet represents indeed the axis of progress of the formula and of the overall technico-economic performance. In the past 5 years, AjInomoTo EuRoLysInE s.A.s. (AEL) has implemented various research programs to fill the gap of knowledge concerning the next limiting AA for piglets. A masterpiece of this program has been the work of Gloaguen (2012) about Valine, Isoleucine, Leucine, Histidine, Phenylalanine, Tyrosine and dietary protein reduction in piglets.

These new outcomes, together with the other works supported by AEL in Europe, are now integrated in our recommended Ideal Amino Acid Profile for piglets. In the present document, the focus is made on the recent advances concerning Tryptophan, the branched-chain AA and the next limiting AA. Data about Lys, met and Thr are based on previous works (van milgen and Le Bellego 2003, sève 1994).

This document is a synthesis and more detailed information is available in the reference list. The objective is to make the link between the scientific data and their implementation in piglets feeds to formulate diets which have to support efficiently the growth of variable population of animals.

Étienne Corrent, aude simongiovanni, Éric le Gall and loïc le tutour.

Preface

4 | Ideal Amino Acid Profile For Piglets

amino acids in Pig nutrition

Determining the indispensableamino acids requirements and the nextlimiting dietary amino acidsTwenty AA are the building blocks of proteins. Each AA is encoded in the DNA as codons, which enables the protein synthesis. All AA are critical to life and nine of them are either not synthesized at all or only in small quantities by pigs (Table 1). They must therefore be supplied through the diet and are called indispensable (or essential by usage) amino acids (IAA or EAA). In practice, it is of great importance to control that the minimum requirements of the IAA are met, even more when dietary CP is reduced.

Essential Amino Acids (AA): AA involved in the biological functions that are necessaryfor life supplied through the diet or synthesised de novo by animals

Indispensable AA Semi-dispensable AA Dispensable AA

AA that cannot be synthesised de novo or at a suffi cient

rate to maintain associated biological functions

AA that can be synthesised de novo but could become

indispensable in specifi c situations when the synthesis is not

suffi cient to cover the requirement

AA that can be synthesisedde novo by the animal

in a suffi cient rate

Lysine (Lys) Glycine (Gly)

Threonine (Thr) Serine (Ser)

Methionine (Met) Cysteine (Cys) Proline (Pro)

Tryptophan (Trp) Alanine (Ala)

Valine (Val) Aspartate (Asp)

Isoleucine (Ile) Asparagine (Asn)

Leucine (Leu) Glutamate (Glu)

Histidine (His) Glutamine (Gln)

Phenylalanine (Phe) Tyrosine (Tyr)

Arginine (Arg)

Table 1: usual classification of the 20 amino acids encoded directly by the genetic code for pigs.

With the feed-use AA avail-able on the market it is possi-ble to formulate diets without minimum constraint on the CP level in which at least 7 AA are co-limiting: Lys, Thr, Trp, Met (and Cys), Val and the next one which deter-mines the resulting dietary CP level (Figure 1). Thus, determining AA requirements aims also at identifying the next limiting AA in local sit-uation which then depends on the local feedstuffs used.

0

100

Lys Thr Met+ Cys

Trp Val Ile Leu His Phe+Tyr

Supply and source of dietary AA in % of the AA requirement

■ Amino Acids from feedstuffs ■ Amino Acids from Feed-use AA

L-Lys

L-Thr

DL-M

et

L-Trp

L-Val

Figure 1: Example of the 7 co-limiting AA in a piglet for-mula in which dietary crude protein is reduced, taking into account requirement of EAA, and using feed-grade AA.

ajinomoto eurolysine s.a.s. | 5

nutritional systems

Evaluating amino acids supply:Total vs digestible AA,Apparent vs Standardized digestibilityThe first and only direct way to estimate AA contents in feedstuffs is to analyze samples using specific methods. Total AA contents can be measured with a good precision using reference methods. The repeatability and reproducibility levels are at least similar to those of proximal analyses. Regressions equations based on total Nitrogen (N) are also available and give an accurate prediction of the total AA contents (Bulletin 32, AEL).

The total AA supplied from feedstuffs cannot be entirely absorbed by the animal’s digestive tract. The amount of each AA that can be absorbed depends on the type of raw material used and on the AA under consideration. The most effective way to formulate feeds for pigs is thus by using the digestible AA values rather than the total ones. This results in a more accurate supply to meet animal requirements and a better economic solution.

Knowledge of the digestibility of each AA in each raw material is therefore essential for the adequacy of the dietary supply of AA (Figure 2). The apparent ileal digestibility (AID) is a first attempt to estimate the AA available for pigs. It represents the difference between the intake and the ileal outflow (excreta). However the ileal outflow contains also endogenous losses with large quantities of endogenous protein and AA. This system can be corrected by considering the basal endogenous losses to give a more accurate value of the feedstuffs digestibility: The standardized ileal digestibility (SID).digestibility: The standardized ileal digestibility (SID).

To

tal

AID

SID

0

100%

74%81%

AID: Apparent ileal digestibilitySID: Standardized ileal digestibilityUndig: Undigestible fractionEL: Endogenous losses

UndigUndigExcreta{

ELEL

➌➋➊

➊ Total AA supply

➋ AID: Total - Excreta

➌ SID: Total - (Excreta - EL)

Figure 2: Representation of the digestibility systems used in pigs. Example based on the Lys digestibility of wheat (InRA, 2004).

For instance, the EvaPig® software proposes coefficients of SID values to apply on total AA and use directly in the feed formulation (www.evapig.com).

6 | Ideal Amino Acid Profile For Piglets

methodology

An usual definition of “the requirement” for practical issues is the minimal amount of the studied nutrient needed to reach optimal or maximum performance, assuming that all the other nutrients are provided in adequate amounts (Hauschild et al., 2010). The practical objective of determining amino acid requirements is to use these values to supply a feed that must support the growth of a heterogeneous population of pigs. However, reported results can be quite variable, and a major part of this variability lies in the methodological aspects which must be taken into account when a review is performed with the objective to assess practical recommendations (Simongiovanni et al., 2012).

Factorial approach vs empirical approach(Haushild et al., 2010)

➔ the factorial approach: Daily requirements are obtained for an individual animal at a specific point in time by combining the estimated requirements for maintenance and production.

➔ the empirical approach: Nutritional requirements are defined as the minimal amount of nutrients needed to maximize or minimize population responses for one or several performance criteria during a given period.

Both methods have strengths and limitations but for practical feeds given to growing animals the definition of the requirement is in the scope of the empirical approach.

In this review, dose-response studies are used to allow estimating AA requirements by depicting the response of a growing population to increased levels of an AA.

Expressing amino acids requirementwithin the ideal protein concept (i.e. ratio to Lys)

In the ideal protein concept, AAs are expressed relatively to Lys. Working with this unit implies that the protocol of a dose-response trial must follow specific conditions: The first limiting factor has to be the studied AA, and the second limiting factor has to be Lys. If not, the AA:Lys requirement estimates will be very variable and undervalued due to unknown factors limiting the response.

In all the trials reviewed here, attention has been paid to assess if the results can be extrapolated as AAs ratio to Lys for practical use.

ajinomoto eurolysine s.a.s. | 7

Digestibility systems and feedstuffs matrixObviously any comparison of dose-response studies must be done within the same nutri-tional system and the result should also be linked to the feedstuffs matrix used in the dose-response.➔ Indeed, AA requirement estimates will be varying depending on the nutritional system as

follow: – Requirement for Total AA > Standardized Ileal Digestible > Apparent Ileal Digestible values, – The gap between each value per system is different for each AA.➔ AA requirement estimates are also very dependent on the reference system (i.e. INRA

2004, NRC 2012, or analyzed values). Direct comparisons should take into account the variability induced by the reference system.

In this review, all values are expressed in SID and were recalculated based on INRA tables (Sauvant et al., 2004).

Models used to interpret the dose-responseA dose-response study must be analyzed with an adequate model to depict the response and estimate the value that maximizes a chosen criteria.➔ The linear-plateau model will always give lower AA requirement values than a curvilin-

ear-plateau model, and has a very poor description of experimental data,➔ The curvilinear-plateau model is superior to determine requirement values to be applied

in practical situation and allows to estimate the marginal efficiency of the response.

In this document, responses and AA requirements are determined based on dose-re-sponse studies using curvilinear-plateau models. They are issued from meta-analysis works when meaningful or review and synthesis of dose-response trials.

8 | Ideal Amino Acid Profile For Piglets

tryptophan

Tryptophan is generally the 4th limiting amino acid in a European cereals based diet. Besides being a constituent of body protein, Trp also plays other important roles in metabolism. It is involved in feed intake regulation,in the immune response and in the animal’s defence system. Increasingthe Trp content in the diet has also been shown to limit the impactof an unfavourable health environment on performance in piglets(Bulletin 30, AEL). Being an indispensable AA for pigs, Trp has to be supplied by the diet in sufficient quantities to cover the animal’s requirement for both growth and health challenged situations.

22% SID Trp:Lys to take advantage of the numerous effects of Trp on piglets’ performanceMore than 130 studies about the effect of Trp on piglets’ performance have been listed by Simongiovanni et al. (2012) who performed a meta-analysis concerning the piglet response to Trp. This AA has been extensively studied due to a practical interest linked to its numer-ous biological functions and its importance for piglet nutrition. Among the 130 studies, 37 have been selected by Simongiovanni et al. (2012) to assess a Trp requirement as a ratio to Lys. Using a curvilinear-plateau model, and based on INRA tables (Sauvant et al., 2004), requirement estimates for ADG, ADFI and G:F have been determined varying from 20 to 22% depending on the criteria to maximize. This level of 22% SID Trp:Lys is the basis of the Trp recommendation proposed by AEL and again confirmed by new dose-responses. Indeed, these new results are in line with the model estimated in the meta-analysis (Figure 3).Indeed, these new results are in line with the model estimated in the meta-analysis (Figure 3).

30

40

50

60

70

80

90

100

SID Trp:Lys (%)

ADG (% of the best performance)

8 10 12 14 16 18 20 22 24 259 11 13 15 17 19 21 23 26

Simongiovanni et al., 2012

Naatjes et al., 2010a Naatjes et al., 2010b

Ma et al., 2010 Petersen, 2011a

Petersen, 2011b

Kluge et al., 2010 Wessels et al., 2011

Figure 3: Effect of Trp on the average daily gain (ADG) of piglets. Comparison of the model determined by simongiovanni et al. (2012) with external Trp dose-reponses (not used in the meta-anlaysis work).

ajinomoto eurolysine s.a.s. | 9

Tryptophan: An amino acid to face efficiently the challenges of the piglet lifeDuring the whole piglet period, diets must enhance feed intake, ensure a maximum growth, support a good health status and avoid stress. The various Trp functions are related to each of these challenges (Figure 4). It is therefore of primary importance to assess an adequate level of Trp in piglet diets.level of Trp in piglet diets.

Ghrelin

Proteinsynthesis

TDO IDO

Kynurenine

Metabolites

PlasmaTryptophan

4th limitingamino acids

Trp : LNAA (% CP)

IFNgamma

Acute phaseprotein

Gastrointestinaltract

Brain

Melatonin Serotoninmood, stress response,

ans sleep regulation

Dietarytryptophan

Trp : LNAA (Tryptophan : Large Neutral Amino Acids ratio)CP (Crude Protein)IDO (Indoleamine 2,3 dioxygenase)TDO (Tryptophan dioxygenase)

Trp : LNAA (Tryptophan : Large Neutral Amino Acids ratio)CP (Crude Protein)IDO (Indoleamine 2,3 dioxygenase)TDO (Tryptophan dioxygenase)

Trp : LNAA (Tryptophan : Large Neutral Amino Acids ratio)CP (Crude Protein)IDO (Indoleamine 2,3 dioxygenase)TDO (Tryptophan dioxygenase)

IncreaseRegulate

Feed intake

Growthperformance

Immune response andhealth maintenance

Animal Behavior

Figure 4: Global pattern of biological roles of Trp and their implications for piglet growth (Bulletin 30, AEL).

The versatile effects of Trp due to its numerous biological functions and its importance for protein deposition lead to recommend a level of 22% SID Trp:Lys for practical piglet diets.

10 | Ideal Amino Acid Profile For Piglets

Valine

Valine is the fifth limiting amino acid after Trp in European diets for piglets. Valine is an indispensable amino acid for body protein deposition and growth, and a dietary deficiency in valine affects the utilization of previous limiting amino acids and consequently animal growth. Valine is a branched-chain amino acid (BCAA), together with isoleucine and leucine. Due to their common catabolic pathway, some interactions exist between them. It is therefore very important to well know their requirements and to ensure that the feed supplies a balanced BCAA profile.

Valine requirement in piglets is confirmedto be 70% SID Val:LysWith about 20 publications mostly in piglets, the number of Val dose-response studies is lower than for Trp but is increasing since L-Valine has been made available for feed-use in 2009 by AEL. Using most of the Val dose-responses studies available, van Milgen et al. (2013) determined by a meta-analysis work that there is a response of +5% for the ADG when SID Val:Lys is increased from 64 to 69%. A data set of 10 trials is presented in Figure 5. These trials were selected to allow to express the performance according to dietary Val:Lys levels. It shows that on average, a value of 70% SID Val:Lys enables to obtain the optimal performance.optimal performance.

0

100

200

300

400

500

600

SID Val:Lys ratio (%)

ADG (g/day)

45 50 55 60 65 70 75 80 85

Mavromichalis et al. (2001) - Exp. 5 -Barea et al. (2009)a - Exp. 4 -Barea et al. (2009)b - Exp. 4 -Dusel et al. (2008)Paulicks et al. (2008)Torrallardona et al. (2008)Vinyeta et al. (2010)Millet et al. (2010)Gloaguen et al. (2012)Soumeh et al. (2013)

Figure 5: sID Val:Lys dose-responses in piglets. Effect on average daily gain (ADG).

ajinomoto eurolysine s.a.s. | 11

Since AA cannot be stored, any excess of AA is catabolized. The group of the BCAA shares in common the two first steps of their catabolism (Figure 6). The second step is under the influence of Leu which activates the BCKDH enzyme complex leading to the catabolism of Val and Ile when Leu is in excess. The Val and Ile catabolism is enhanced even if these AA are deficient in the diet (Bulletin 35, AEL). Indeed, it has been shown that when dietary

Impact of the branched-chain AA metabolismon performance

small intestin

e

muscle

PROTEIN SYNTHESIS CATABOLISM

KIV

KMV

KIC

A-CoA1

A-CoA2

A-CoA3

GlucogenicGlucogenic

KetogenicKetogenic

BCAA BCKALYS VAL

ALAGLU NH3

GLN

TRP

LEU THR ILE KIV

KMV

KIC

liver

VAL

ILE

LEU

gut �ow

VAL ILE LEU

VALILE

LEU

BCAT

BCKDH

Figure 6: Global pattern of the branched-chain amino acids metabolism.

12 | Ideal Amino Acid Profile For Piglets

Leu supply is high, the requirement per se of Val is not affected by the Leu content but the response to Val is even more increased (Gloaguen et al., 2012, Figure 7). In addition, piglets avoid (decrease) to eat BCAA imbalanced diet (i.e. Val deficient). Indeed, Gloaguen et al. (2012) shown that a piglet is able to detect within 1 hour after meal the dietary Val deficiency and consequently reduces its feed intake. The combination of the decreased feed intake and feed efficiency results in a drastic decrease of the ADG.and feed efficiency results in a drastic decrease of the ADG.

SID Val:Lys ratio (%)

ADG, % of the best performance FCR, % of the best performance

50556065707580859095

100

55 60 65 70 75 80 85SID Val:Lys ratio (%)

100

102.5

105.0

107.5

110.0

112.5

115.0

55 60 65 70 75 80 85

Barea et al. (2009) Low Leu Glaoguen et al. (2012) High Leu Area of the requirement

Figure 7: Effect of sID Val:Lys on piglets performance with (Gloaguen et al., 2012) or without (Barea et al., 2009) large supply of Leucine.

Among the BCAA,Val is the limiting AA in the piglet diets when no L-Valine is added. It is therefore crucial to control the minimum levels of dietary Val. The use of 70% SID Val:Lys allows to counter act any imbalance in BCAA supply and to maximize feed intake, growth and feed efficiency of piglets.

ajinomoto eurolysine s.a.s. | 13

isoleucine

Isoleucine is a potential limiting AA after Val and its dietary level could determine the dietary protein level in a formula using the complete range of available feed-use AA. It is therefore necessary to consider this AA in the formulation and to assess a safe requirement level. The literature is important concerning Ile but controversial results were published on the requirement estimates. However, the factor of variation has been described and today robust recommendations on Ile levels can be established for commercial diets.

53% SID Ile:Lys is recommended for pigletsIsoleucine belongs to the group of the branched-chain AA together with Val and Leu, but also to the Large Neutral AA group (LNAA) which includes BCAA, Trp, His, Phe and Tyr. This group of AA shares a common saturable transporter at the blood brain barrier level. An analysis of literature about the Ile requirement in piglets must take into account these factors. Van Milgen et al. (2012) ran a meta-analysis work on the response of growing pigs to Ile and concluded that the requirement is influenced by the presence of spray-dried blood-cells (SDBC) in the diet. Indeed, in these products the AA pattern is very imbalanced (Figure 8), and their use increases the Ile requirement level. Due to their poor Ile contents, SDBC have been extensively used in Ile dose-response studies but the requirement estimates used to be very variable and very high in comparison to requirement estimates based on blood-free diets (Bulletin 35, AEL).diets (Bulletin 35, AEL).

Spray dried blood cells

Soybean meal

0

3

5

8

10

13

15Lys:CP

Ile:CP

Leu:CP

Val:CP

His:CP

Phe:CP

Figure 8: Amino acids profile of sDBC vs soybean meal; as % of crude protein (CP).

14 | Ideal Amino Acid Profile For Piglets

A review of the Ile dose-responses in piglets is proposed in Figure 9; only the trials in which blood-free diets were used were selected. Van Milgen et al. (2013) proposed a minimum requirement of 50% SID Ile:Lys when blood-free diets are used. For practical purpose we recommend the use of 53% SID Ile:Lys. When using blood-cells attention must be paid to the dietary level of Ile with an increased requirement.

0

200

100

300

400

500

600

SID Ile:Lys ratio (%)

ADG (g/d)

30 35 70 75 806540 45 50 55 60

Wiltafsky et al. (2009) Exp3.Gloaguen et al.

Gloaguen et al. (2012)

Trautwein et al. (2010)

Millet et al. (2010)

Soumeh et al. (2013)

Noorgard et al. (2012)

Figure 9: sID Ile:Lys dose-responses in piglets, blood-free diets. Effect on average daily gain (ADG).

ajinomoto eurolysine s.a.s. | 15

leucine

Leucine is a BCAA, generally in excess supply in current piglet’s diets. Leucine plays a key role in the catabolism of the BCAA. A Leu excess together with Val and/or Ile deficiencies is described in the literature to be detrimental for piglet performance (Bulletin 35, AEL). Indeed, any imbalance within BCAA dietary supply must be avoided. However, a recommendation of a leucine maximum is not meaningfull since the issue lies in the balance with the others BCAA. The most efficient way is to formulate closer to the leucine requirement and to control the minimum Val and Ile levels. It is therefore necessary to assess the animal response to Leu and the requirement of Leu to determine to what extent Leu levels can be reduced.

Leucine levels can be reducedto 100% SID Leu:Lys in piglet dietsLiterature about Leu requirement in piglets is scarce but recent trials have been performed in Europe and are reported in Figure 10. For instance, Gloaguen et al. (2013) published a study about the Leu requirement in piglets and concluded that 102% SID Leu:Lys was necessary on aver-age to maximize the piglet perfor-mance. However, as shown in Table 2, a 10% deficiency slightly affects the response, which is confirmed by recent trials conducted in cooperation with AEL and shown in Figure 10.

Criteria to maximize ADFI ADG Gain to Feed

SID Leu:Lys requirement estimates (%) 102.4 101.9 97.2

-10% defi ciency affects the response by -1.9% -3.3% -2.0%

Table 2: Results of Gloaguen et al. (2013). sID Leu:Lys requirement estimates and effect of a 10% deficiency on performance, based on a curvilinear-plateau model.

Based on these data a level of 100% SID Leu:Lys is recommended for piglet diets.

to 100% SID Leu:Lys in piglet diets

100

200

300

400

500

600

SID Leu:Lys (%)

ADG (g/d)

60 70 14013080 90 100 110 120

Wessels et al. (2013)

Augspurger and Baker (2004), 1

Augspurger and Baker (2004), 2

Gloaguen et al. (2012), 1

Gloaguen et al. (2012), 2

Soumeh et al. (2013)

Figure 10: sID Leu:Lys dose-responses in pig-lets. Effect on average daily gain (ADG).

16 | Ideal Amino Acid Profile For Piglets

Histidine

Histidine is considered as an essential AA for piglets but its requirement has not been extensively studied. The current dietary levels in piglets’ diets are not limiting and His could be limiting after the BCAA group depending on the structure of the formula (i.e. feedstuffs AA contents). To be complete, an ideal AA profile must account for His level.

Overview of the Histidine dose-response studies in pigletsIn order to express the His requirement within the ideal protein concept, Gloaguen et al. (2013) performed two His dose-responses in piglets (10 to 22 kg LW) in which Lys was sublimiting (1.00% SID). The results of this study are presented in Figure 11 and Table 3, and an average requirement of 32% SID His:Lys has been assessed.and an average requirement of 32% SID His:Lys has been assessed.

100

200

300

400

500

1.25

1.50

1.75

2.00

2.25

SID His:Lys (%)

ADG (g/d) FCR

16 22 26 28 30 34 36 4240 442018 24 32 38 46

Gloaguen et al. (2013), 1

Gloaguen et al. (2013), 2

Criteria to maximize ADFI ADG Gain to Feed

SID His:Lys requirement estimates (%) 32.7 31.6 28.8

-10% defi ciency affects the response by -1.6% -2.6% -1.5%

Table 3: Results of Gloaguen et al. (2013). sID His:Lys requirement estimates and effect of a 10% deficiency on performance, based on a curvilinear-plateau model.

Two other studies had been performed in the past (Table 4) but the requirement estimates are expressed in different units which makes difficult the synthesis. However, considering the response when His is deficient, the estimate of 32% SID His:Lys is safe to be used in low protein diets.

Body weight Response criteria Requirement estimates

Izquierdo et al., 1988 10-20 kg ADFI, ADG, G:F 0.36% total His

Li et al., 2002 10-20 kg ADFI, ADG, G:F 30% AID His:Lys

Gloaguen et al., 2012 10-22 kg ADFI, ADG, G:F 32% SID His:Lys

Table 4: Literature available about the His requirement in piglets.

Figure 11: sID His:Lys dose-responses in piglets. Effect on average daily gain (ADG) and feed conversion ratio (FCR).

ajinomoto eurolysine s.a.s. | 17

Phenylalanine and tyrosine

Phenylalanine and Tyrosine are aromatic AA also classified as indispensable AA and semi-dispensable AA, respectively. The current piglet diets still provide large amount of Phe and Tyr, even after the dietary crude protein reduction which is currently achievable using the available feed-use AA.The requirement of these AA had therefore not been studied.Pioneer works supported by AEL are presented here.

First work to refine a Phenylalanineand Tyrosine requirement in pigletPhenylalanine can be converted to Tyr by irreversible hydroxylation through an enzyme which is activated by Phe itself. Tyrosine is considered as a semi-dispensable AA because a Tyr deficiency could occur when the dietary Phe supply is insufficient to supply Tyr. Because Phe can be used for Tyr synthesis, the requirement for the latter had not been explicitly quantified and the requirement had been usually expressed in recommended AA profile as the sum of Phe + Tyr.

Recommended requirements vary from 54 to 57% SID Phe:Lys and 93 to 111% SID (Phe+Tyr):Lys. Gloaguen et al. (2014) worked on dose-responses to Phe and Tyr and on the possibility to substitute Tyr by Phe. It is shown that the minimum SID Phe:Lys requirement is about 54% and the maximum SID Tyr:Lys requirement is about 43% (Table 5).

Criteria to maximize ADFI ADG Gain to Feed

SID Phe:Lys requirement estimates (%) 54.8 54.2 52.6

-10% Phe defi ciency affects the response by -1.8 -3.0 -1.7

SID Tyr:Lys requirement estimates (%) 42.8 39.7 -

-10% Tyr defi ciency affects the response by -0.6 -0.7 -

Table 5: Results of Gloaguen et al. (2014). sID Phe and Tyr to Lys requirement estimates and effect of a 10% deficiency on performance, based on a curvilinear-plateau model.

Nevertheless, it seems that considering the sum of Phe+Tyr to assess the requirement is not relevant since the substitution of Tyr by Phe was not successful in this work (data not shown here). This could be linked to the particular usage (oxidation) of the Tyr obtained from Phe in comparison to the dietary Tyr. More research is needed on this issue, and for practical feeds we still recommend a minimum of 95% SID (Phe+Tyr):Lys with minimum SID Phe:Lys of 55%.

18 | Ideal Amino Acid Profile For Piglets

ideal amino acid Profile

The review of the available amino acids dose-responses and the very new trials concerning the less studied AA are a basis to refine recommendation of an ideal AA profile for practical piglets diets. However, in addition to the scientific data available, making a decision on which dietary AA levels have to be used must take into account others parameters inherent in feed formulation. AEL’s nutritionists work in close collaborations with institutes all over Europe to be able to recommend a robust amino acid profile that ensures the best performance of piglets raised in variable commercial conditions in Europe.

Update of the Ideal Amino Acid Profilefor PigletsIn growing animals, the concept of “ideal protein” or ideal AA profile is a concept where AA pattern (defined as a percentage of lysine) maximizes growth, nitrogen retention or another response criterion of interest. In this profile, all indispensable amino acids are equally limiting for performance, just covering the requirements for all physiological functions. Lysine has traditionally been used as a reference because it is the first limiting AA for growth in pigs. It is frequently assumed that the ideal protein profile does not change for a given growing stage. In practical nutrition, this offers the advantage that the lysine requirement will vary (per kg of feed or per MJ of energy), but not the ideal amino acid profile expressed relative to lysine. Each of these ratios can thus be directly introduced as a constraint in feed formulation.

SID ValuesBSAS (2003)

UKNRC (2012)

USA(1)VSP (2013)

DKINRA

(2013)(2) FRAjinomoto

Eurolysine (2013)

Lys:Lys 100 100 100 100 100

Thr:Lys 65 59 61 65 65

Met:Lys 30 29 32 30 30

(Met+Cys):Lys 59 55 54 60 60

Trp:Lys 19 16 20-22 22 22

Val:Lys 70 63 67 70 70

Ile:Lys 58 51 53 52(3) 53(3)

Leu:Lys 100 100 102 101 100

His:Lys 34 34 32 31 32

Phe:Lys 57 58 57 54 55

(Phe+Tyr):Lys 100 93 111 - 95

Tyr:Lys - - - 40 -

Indicatives recommended SID Lys levels: From 1.35 to 1.15% for 6-12 and 12-25 kg piglet live weight respectively.1) AA profi le recalculated from the factorial approach used by NRC (2012)2) Gloaguen et al. (2013)3) Requirement is given for blood-free diet

Table 6: AjInomoTo EuRoLysInE s.A.s. Amino Acids profile for piglets and comparison to other profiles.

ajinomoto eurolysine s.a.s. | 19

A comparison of the different AA profiles (Table 6) shows that there is still variability between the different institutes. This is due for instance to different methodological approaches, as already discussed. As an example, an important difference between NRC (2012) and INRA (2013) can be explained by the factorial method used by NRC and the empirical approach used by INRA. The AA levels calculated by NRC maximize nitrogen retention, while the AA profile given by INRA maximizes growth performance (dose-response studies).Others factors that lead to recommend an AA profile are listed in Figure 12. Apart from the methodological aspects, the difference between recommended AA profiles lies in the global risk management of the feed formulation. In a context of general usage of low protein diets as it is in Europe, the risk is taken on each AA instead of crude protein, which is more relevant since crude protein is not a predictor of the piglet’s performance. Then, by using AEL AA profile, the feed formulation can be done safely without minimum on dietary crude protein.

Experimentaldata Reference

feedstuffsmatrix of the

trials

Statisticalmodels

Factorial vsempirical approach

Responseto the AA

Riskmanagement

Variabilityof the

pig populationto feed

Accuracyof the userfeed matrix

Use of LowProtein Diets

Interactionsbetween AA

Criteriato optimize

Ideal AApro�le

for practice

Figure 12: Example of factors to consider to assess an amino acid profile for piglet commercial diets.

20 | Ideal Amino Acid Profile For Piglets

low Crude Protein Diets

Knowing the amino acid contents of feedstuffs, their digestibility, using net energy values, and implementing the AEL ideal AA profile, allow to implement efficiently low protein diets in piglets. The use of low CP levelsin piglets’ diets is increasing in Europe for health, economic and environmental reasons. This technic is already known and furthermore implemented since the range of available feed-use AA has increased(i.e. L-Valine). There is still room for further dietary CP reduction in practical feeds without compromising growth performance.

Using low protein diets in piglets: Efficient and safe➔ A lower supply of dietary CP reduces the global amount of undigested protein supplied

in the distal intestine of piglets and results in a better acidification (and digestion) of the bolus. This ends by a lower proliferation of the pathogenic bacteria and significantly reduces the occurrence of diarrhea (Lordelo et al., 2008).

➔ By formulating on each EAA instead of minimum dietary CP, the most balanced AA profile is supplied to the animal avoiding lack and excess of AA, the amount of protein rich feedstuffs is reduced in the formula and substantive cost savings are achievable. By applying a precise AA profile, risk management can be implemented and the best opportunities of using local feedstuffs and co-products can be taken.

➔ Reducing dietary CP is one of the best available technics to reduce nitrogen output into the environment: -1 point of dietary CP results in -10% of nitrogen excretion.

Using the ideal AA profile recommended by AEL and the available feed-use AA, dietary CP can be reduced safely and efficiently as shown in the following trials presented (Table 7).can be reduced safely and efficiently as shown in the following trials presented (Table 7).

Body weight

(kg)

Dietary CP (%)

SID Lys (%)

ADFI (g/d)

ADG (g/d)

FCR PAEL

Ideal AA profi le

Lordelo et al.(2008)

7-2320.5 1.12 932 583 1.60

ns17.0 1.12 941 571 1.65 ✓

Jansman et al. (2008)

10-2519.0 1.03 869 567 1.54

ns16.0 1.03 866 568 1.52 ✓

Norgaard and Fernandez (2009)

9-2119.0 1.10 627 445 1.40

ns17.0 1.10 635 449 1.41 ✓

Vinyeta et al.(2010)

8-2517.5 0.94 857 564 1.52

ns15.5 0.94 873 567 1.54 ✓

Gloaguen et al. (2013)

12-2317.6 1.00 766 450 1.70

ns15.6 1.00 775 454 1.71 ✓

Jansman et al. (2013)

8-2516.8 1.00 835 548 1.49

ns15.4 1.00 816 564 1.48 ✓

Table 7: Effect of lowering dietary crude protein (CP) on piglet performance (diets using only available feed-use AA).

AJINOMOTO EUROLYSINE S.A.S. | 21

A pioneer work: Formulating dietsfor piglets without soybean mealAfter a complete review and work on AA requirements, Gloaguen et al. (2013) proposed to test to what extent the CP content of piglets diets can be reduced by substituting soybean meal by wheat, barley, corn and free AA, without affecting performance. The study is based on the AEL AA profile. In the first 4 diets, soybean meal was still used and CP decreased from 17.6 to 11.8%. In additional 2 diets, only cereals and free AA were used to test the effect of nitrogen addition (13 vs 14% CP by L-Glu addition in treatment 6). The formulas and results are summarized in Table 8.

Treatments 1 2 3 4 5 6

Feedstuffs used CEREALS - SBM - L-AA CEREALS & L-AA

Cereals (%) 50 60 80 85 80 80

Soybean Meal (%) 25 20 10 2 0 0

L-Lys HCL (%) 0.28 0.46 0.70 0.92 1.00 1.00

DL-Met, L-Thr, L-Trp + ++ +++ ++++ ++++ ++++

L-Val - + ++ +++ ++++ +++

Others L-EAA - - + ++ +++ +++

Others L-NEAA - - - - + ++

SID Lys (%) 1.00 1.00 1.00 1.00 1.00 1.00

Ideal AA pro� le ✓ ✓ ✓ ✓ ✓ ✓

Crude Protein (%) 17.6 15.6 13.5 11.8 13.0 14.0 P

BWi, kg 12.7 12.7 12.6 12.6 13.0 12.8 0.60

BWf, kg 22.2a 22.2a 21.9a 20.1b 21.8a 22.3a <0.01

ADFI, g/d 766 775 779 734 810 782 0.55

ADG, g/d 450a 454a 442a 358b 450a 451a <0.01

G:F, g/g 0.59a 0.59a 0.57a 0.49b 0.52b 0.58a <0.01

Table 8: Effect of reducing dietary crude protein content on performance of piglets(Gloaguen et al., 2013).

➔ The feed intake is not influenced whatever is the protein level,➔ Growth performance are maintained till the level of 13.5 – 14.0% CP (treatments 1, 2,

3 & 6)➔ Comparing diets 5 and 6 shows that at 13% CP, nitrogen was limiting: Adding a N source

up to 14% CP allows to recover performance as in treatment 1,➔ This trial indicates that efficiency of utilizing AA is not lower for free AA compared with

protein bound AA in pigs offered feed ad-libitum,➔ In the successful treatment 6, 78% of the SID Lys was supplied by L-Lys-HCL.

This trial shows that there might be a minimum of N between 13 and 14% CP (for 1.00% SID Lys). However, it confirms that tremendous dietary protein reduction is achievable in current piglet feeds. It indicates also that when using the AEL ideal AA profile, dietary CP can be reduced efficiently in piglet diets by using feed-use AA.

22 | Ideal Amino Acid Profile For Piglets

Conclusions

Ideal Amino Acid profile for piglets(up to 25 kg live weight) expressed in

standardized ileal digestible (SID) values.

SID ValuesAjinomoto

Eurolysine (2013)Lys:Lys 100Thr:Lys 65Met:Lys 30(Met+Cys):Lys 60Trp:Lys 22Val:Lys 70Ile:Lys 53*Leu:Lys 100His:Lys 32Phe:Lys 55(Phe+Tyr):Lys 95

*Ile requirement for diets free of blood-meal or blood-cells

☛ indispensable amino acids, as essential nutrients, must be supplied in the diets for piglets. as they predict performance they represent factors of variability of the growth and must be monitored with care to get the best performance in variable conditions. as a first step, amino acid contents in feedstuffs have to be estimated and digestible values used as predictors. Beside chemical analyses, table values, regressions equations based on nitrogen, and coefficients of digestibility contribute to estimate the supply and quality of amino acids in feedstuffs.

☛ the increasing knowledge about amino acid nutrition allows to recommend a robust ideal amino acid profile that supports feed intake, growth, nutrients efficiency and health challenges of the piglets.

☛ the proposed amino acid profile by ael is based on a strong scientific background, taking also into consideration the practical issues of animal production and particularly feed production. this profile provides a tool to optimize feedon each essential amino acid instead of crude protein.this technic enables to reach the best solution regarding the ingredients used in the formula. last but not least, this profile is a tool to reduce safely and efficiently the crude protein content in piglets diets by using the available feed-use amino acids in combination with the local feedstuffs which makes possible substantial feed costs reduction.

ajinomoto eurolysine s.a.s. | 23

references

n Augspurger N.R., D.H. Baker, 2004. An estimate of the leucine requirement for young pigs. J. Anim. Sci., 79, 149-153.

n Barea, R., L. Brossard, N. Le Floc’h, Y. Primot, D. Melchior, and J. van Milgen. 2009a. The standardized ileal digestible valine-to-lysine requirement ratio is at least seventy percent in postweaned pig-lets. J. Anim. Sci. 87, 935-947.

n Barea, R., L. Brossard, N. Le Floc’h, D. Melchior, L. Le Bellego, and J. van Milgen. Détermination du besoin en valine chez le porcelet. 41, 109-116. 2009. Paris. JRP. 3-2-2009b.

n British Society of Animal Science 2003. Nutrient requirement standards for pigs. British Society of Animal Science, Penicuik, UK.

n Bulletin 30. Primot, Y. and D. Melchior. 2008. Tryptophan in young pigs: An essential nutrient with numerous biolog-ical functions. Ajinomoto Eurolysine s.a.s.

technical information 30.

n Bulletin 32. Relandeau, C. and M. Eudaimon. Ajinomoto Eurolysine formu-lator’s handbook, measuring and predict-ing amino acid contents in feedingstuffs. Ajinomoto Eurolysine s.a.s. technical infor-mation 32. 2008.

n Bulletin 35. Corrent, E., A. Simongiovanni, and Y. Primot. Branched-Chain ami-no acids nutrition in piglets. Ajinomoto Eurolysine s.a.s. technical information 35. 2010.

n Gloaguen, M. 2012. Identification des acides aminés limitants secondaires pour la croissance des porcelets dans des régimes à basse teneur en protéines et

des mécanismes de régulation de la con-sommation volontaire lors d’une carence en valine. Thèse de Doctorat d’Agrocam-pus Ouest. France.

n Gloaguen M, N. Le Floc’h, L. Brossard, R. Barea, Y. Primot, E. Corrent and J. van Milgen. 2011. Response of piglets to the valine content in diet in combination with the supply of other branched-chain amino acids. Animal 5, 1734-1742.

n Gloaguen M, N. Le Floc’h, Y. Primot, E. Corrent and J. van Milgen. 2012. Providing a diet deficient in valine but with excess leucine results in a rapid decrease in feed intake and modifies the postpan-drial plasma amino acid and α-keto acid concentrations in pigs. J. Anim. Sci. 90, 3115-3142.

n Gloaguen M, N. Le Floc’h, Y. Primot, E. Corrent and J. van Milgen. 2013. Response of piglets to the standardized ileal digestible isoleucine, histidine and leucine supply in cereal-soybean meal-based diets. Animal, 6, 901-908.

n Gloaguen M, N. Le Floc’h, Y. Primot, E. Corrent and J. van Milgen. The use of free amino acids in piglet diets allows the for-mulation of very low crude protein diets. 134, 161-162. 2013. Sacramento, CA, USA. EAAP. Energy and protein metab-olism and nutrition in sustainable ani-mal production. Wageningen Academic Publishers, Wageningen, the Netherlands.

n Gloaguen M, N. Le Floc’h, and J. van Milgen. 2013 Le point sur la couverture des besoins en acides aminés chez le porcelet dans des régimes à basse teneur en protéines. INRA Prod. Anim. 26 (3), 277-288.

24 | Ideal Amino Acid Profile For Piglets

n Gloaguen M, N. Le Floc’h, Y. Primot, E. Corrent and J. van Milgen. 2014 Response of performance of piglets fed with low protein diets containing vari-able levels of phenylalanine and tyrosine. Submitted.

n Hauschild, L., C. Pomar, and P.A. Lovatto. 2010. Systematic comparison of the empirical and factorial methods used to estimate the nutrient requirements of growing pigs. Animal. 4, 714-723.

n Izquierdo OA, KJ. Wedekind and DH. Baker. 1988. Histidine requirement of the young pig. Journal of Animal Science 66, 2886-2892

n Jansman, A. J. M. and J. Th. M. van Diepen. The requirement of valine and isoleucine in young piglets. 06NL03. 2008. Trial report.

n Jansman, A. J. M. Low dietary crude pro-tein diets in piglets. 13NL01. 2013. Trial pre-report.

n Kluge, H., J. Bartelt, and G. Stang. Studies on the Trp requirement of piglet. 9 Boku Symposium Tiërernährung. 2010.

n Li DF, ZH. Zhang and LM. Gong. 2002. Optimum ratio of histidine in the piglet ideal protein model and its effects on the body metabolism II. Optimum ratio of histidine in 10-20 kg piglet ideal pro-tein and its effects on blood parameters. Archives of Animal Nutrition-Archiv Fur Tierernahrung 56, 199-212

n Lordelo, M. M., A. M. Gaspar, L. Le Bellego, and J. P. B. Freire. 2008. Isoleucine and valine supplementation of a low-protein corn-wheat-soybean meal based diet for piglets: growth per-formance and nitrogen balance. J. Anim. Sci 86:2936-2941.

n Ma, L., Z. P. Zhu, R.B. Hinson, G. L. Allee, J. D. Less, D. D. Hall, H. Yang, and D. P. Holzgraefe. 2010. Determination of SID Trp:Lys ratio requirement of 11- to 22- kg pigs fed diets containing 30% DDGS. J. Anim. Sci. Vol. 88, E-Suppl. 3

n Mavromichalis, I., B. J. Kerr, T. M. Parr, D. H. Albin, V. M. Gabert, and D. H. Baker. 2001. Valine requirement of nursery pigs. J. Anim. Sci. 79:1223-1229.

n Millet, S., J. De Boever, M. Aluwé, M. De Paepe, and D. De Brabander. Optimal ileal digestible valine/lysine ratio for the per-formance of piglets. EAAP Conference (Heraklion, Greece). 2010.

n Millet, S., J. De Boever, M. Aluwé, and D. De Brabander. Effect of increasing ileal digestible isoleucine/lysine ratio on perfor-mance of piglets. Trial report 10BE01.

n Naatjes M, JK. Htoo, KH. Tölle and A. Susenbeth. 2010. Effect of dietary tryptophan to lysine ratio on perfor-mance of growing pigs fed wheat-bar-ley or corn-soybean meal based diets. In Energy and protein metabolism and nutrition EAAP Publication No. 127, 605-606. Wageningen Academic Publishers, Wageningen, the Netherlands.

n National Research Council. 2012. Nutrient Requirements of Swine. National Academy Press, Washington, DC.

n Noblet, J., A. Valancogne, G. Tran, and Ajinomoto Eurolysine s.a.s. EvaPig®. [1.0.1.4]. 2008.

n Nørgaard, J. V. and J. A. Fernandez. 2009. Isoleucine and valine supplemen-tation of crude protein-reduced diets for pigs aged 5-8 weeks. Anim. Feed Sci. Tech. 154:248-253.

ajinomoto eurolysine s.a.s. | 25

n Nørgaard, J. V., A. Shrestha, U. Krogh, N. M. Sloth, K. Blaabjerg, H. D. Poulsen, P. Tybirk, and E. Corrent. 2013. Isoleucine requirement of pigs weighing 8 to 18 kg fed blood cell-free diets. J. Anim. Sci. 2013.91:3759–3765.

n Paulicks, B. R. Experimental estimation of valine requirement of weaned piglets (12-25 kg). TUM. 08DE01, 1-7. 2008. Munich. Trial report.

n Petersen, G. 2011. Est imat ion of the ideal standardized ileal digestible Tryptophan:Lysine ratio in 10 to 20 kg pigs. Doctor of philosophy, University of Illinois at Urbana Champaign, USA.

n Sauvant D, Perez J-M and Tran G 2004. Table of composition of nutritional value of feed materials. Pigs, Poultry, Cattle, Sheep, Goats, Rabbits, Horses, Fish. 2nd ed. INRA Editions, Paris.

n Seve B., 1994. Alimentation du porc en croissance: intégration des concepts de protéine idéale, de disponibilité digestive des acides aminés et d’énergie nette. INRA production animal, 7, 275-291.

n Simongiovanni A., E. Corrent, N. Le Floc’h, J. van Milgen, 2012. Estimation of the tryptophan requirement in piglets by meta-analysis. Animal, 6, 594-602.

n Simongiovanni, A., E. Le Gall, Y. Primot, E. Corrent. Estimating amino acid require-ments through dose-response exper-iments in pigs and poultry. Ajinomoto Eurolysine Technical Note, 2012. www.ajinomoto-eurolysine.com

n Soumeh, E.A., J. van Milgen, N. M. Sloth, E. Corrent, H. D. Poulsen, and J. V. Nørgaard 2013. Estimation of the opti-mum ratio of standardized ileal digestible

isoleucine to lysine for 8 to 19 kg pigs in diets based on wheat, barley and soy protein concentrate. Trial report.

n Soumeh, E.A., J. van Milgen, N. M. Sloth, E. Corrent, H. D. Poulsen, and J. V. Nørgaard 2013. Estimation of the opti-mum ratio of standardized ileal digestible valine to lysine for 7 to 18 kg pigs in diets based on wheat, barley and soy protein concentrate. Trial report.

n Soumeh, E.A., J. van Milgen, N. M. Sloth, E. Corrent, H. D. Poulsen, and J. V. Nørgaard 2013. Estimation of the opti-mum ratio of standardized ileal digestible leucine to lysine for 6 to 17 kg pigs in diets based on wheat, barley and soy protein concentrate. Trial report.

n Trautwein, J., G., Dusel and J. Bartelt. Valine requirement of weaned piglets fed low-protein diets. In Energy and protein metabolism and nutrition EAAP Publication No. 127, 631-632 Wageningen Academic Publishers, Wageningen, the Netherlands.

n Trautwein, J., G., Dusel, Bartelt, J. and E. Corrent. Valine and Isoleucine require-ment of weaned piglets fed low-protein diet (Bedarfsermittlung von Valin und Isoleucin in Niedrig-Protein-Rationen bei Absetzferkeln) 9 Boku Symposium Tiërernährung. 2010.

n Torrallardona, D. Valine:Lysine ratio for piglets between 0 to 4 weeks post wean-ing. IRTA. 08SP04 Trial Report. 2008.

n Van Milgen, J. and L. Le Bellego. 2003. A meta-analysis to estimate the optimum threonine to lysine ratio in growing pigs. J. Anim. Sci. Suppl. 81 – 140: 553.

26 | Ideal Amino Acid Profile For Piglets

n Van Milgen J., M. Gloaguen, N. Le Floc’h, L. Brossard, Y. Primot, and E. Corrent. 2012. Meta-analysis of the response of growing pigs to the isoleucine concentra-tion in the diet. Animal, 6, 1601-1608.

n Van Milgen J., M. Gloaguen, N. Le Floc’h, L. Brossard, Y. Primot, and E. Corrent. Meta-analysis of the response of grow-ing pigs to valine content of the diet. 134, 339-340. 2013. Sacramento, CA, USA. EAAP. Energy and protein metab-olism and nutrition in sustainable ani-mal production. Wageningen Academic Publishers, Wageningen, the Netherlands.

n Vinyeta, E. and J. van de Klis. Pilot study on valine requirements of weaned piglets. Schothorst Feed Research. 09NL02 Trial Report. 2010.

n Vinyeta, E., R. Gerritsen, M. Rovers and E. Corrent. Le besoin en valine des por-celets (Valine requirements of weaned pig-

lets). 2011. Journées Recherche Porcine, Paris, France 43. 131-132.

n VSP. P. Tybirk, N. M. Sloth and L. Jørgensen. Nutrient requirement standards. 18th edition of nutrient Danish standards. 2013.

n Wiltafsky, M. K., J. Bartelt, C. Relandeau, and F. X. Roth. 2009. Estimation of the optimum ratio standardized ileal digestible isoleucine to lysine for 8- to 25-kilogram pigs in diets containing spray-dried blood cells or corn gluten feed as a protein source. J. Anim. Sci. 87:2554-2564.

n Wessels, A., H. Kluge, and G. Stang. 2011 Effect of Trp on piglet performance. Trial report. Martin-Luther-Universität Halle-Wittenberg Germany. AEL 10DE02.

n Wessels, A., H. Kluge, and G. Stang. Leucine requirement in piglet. Trial report. Martin-Luther-Universität Halle-Wittenberg Germany.

www.ajinomoto-eurolysine.com

153, rue de Courcelles75817 Paris Cedex 17 – France

Phone: + 33 1 44 40 12 12


Recommended