A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T From crude protein to precision protein: implications for the ideal protein concept Jaap van Milgen, Mathieu Gloaguen, Alberto Conde, Roberto Barea, Ludovic Brossard and Nathalie Le Floc’h

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Introduction Expressing amino acid requirements and interpreting the response to the amino acid supply Responses to the supply of branched-chain amino acids (Val and Ile) How far can we go with precision protein? Conclusions Outline

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Introduction Expressing amino acid requirements and interpreting the response to the amino acid supply Responses to the supply of branched-chain amino acids (Val and Ile) How far can we go with precision protein? Conclusions Outline

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Reducing the CP content in the diet: reduces the risk of digestive problems increases the efficiency of N utilization reduces N excretion With the use of L-Lys, DL-Met, L-Thr, L-Trp, and L-Val, more amino acids potentially become colimiting Little is known about the “requirements” of secondary amino acids Introduction

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T The CP content of amino acids is rather “crude”

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Using free AA allows improving the AA profile no free AA, 1.0% SID Lys CP = 21.6% cost = 100

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T with free AA, 1.0% SID Lys CP = 17.1% cost = 87 Using free AA allows improving the AA profile

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T with free AA, 1.0% SID Lys CP = 15.5% cost = 89 Using free AA allows improving the AA profile

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Introduction Expressing amino acid requirements and interpreting the response to the amino acid supply Responses to the supply of branched-chain amino acids (Val and Ile) How far can we go with precision protein? Conclusions Outline

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Expressing AA requirements (AID, SID, % of Lys) Experimental considerations Estimating “the” requirement vs the response Expressing amino acid requirements and interpreting the response to the amino acid supply

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T available minimum oxidation excess retained diet ileal indigestible specific endogenous losses standardized ileal digestible Expressing amino acid requirements apparent ileal digestible maintenance basal endogenous losses

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T AIDBasal endogenous lossesSID Lys100 Met Met+Cys Thr Trp Val Ile Leu Phe Phe+Tyr His Amino acid requirements are typically greater when expressed on a SID basis

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T The second-limiting factor in a dose-response study should be known

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T The second-limiting factor in a dose-response study should be known Expressing the amino acid requirement relative to Lys is valid only when Lys is second-limiting in the study

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Estimating “the” requirement vs the response

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T The amino acid requirement will typically decline during the experiment response no response partial response

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Introduction Expressing amino acid requirements and interpreting the response to the amino acid supply Responses to the supply of branched-chain amino acids (Val and Ile) How far can we go with precision protein? Conclusions Outline

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T INRA (1993)NRC (1998)BSAS (2003) Lys100 Val68 70 Ile Leu Ideal amino acid profile: all amino acids are equally limiting

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T leucinevalineisoleucine  -keto-  -methylvalerate (KMV)  -ketoisovalerate (KIV)  -ketoisocaproate (KIC) BCAA amino transferase  -methylbutyryl CoA (glucogenic + ketogenic) isobutyryl CoA (glucogenic + ketogenic) isovaleryl CoA (ketogenic) BCKA dehydrogenase Metabolism of branched-chain amino acids

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T ValIleLeu Publications20221 (+1) -peer-reviewed9121 (+1) -other1110 Dose response experiments28462 (+2) -peer-reviewed15242 (+2) -other1322 What do we know about BCAA requirements in growing pigs?

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T BW range (kg)Reported requirementRelative to NRC (1998) Jackson et al., % Val51% Lewis and Nishimura, % AID Val80-105% Liu et al., g SID Val/d98% James et al., % SID Val90-97% Mavromichalis et al., g SID Val/MJ ME101% “ g SID Val/MJ ME105% Gaines et al., % SID Val114% “ % SID Val114% Paulicks et al., % SID Val:Lys99% Torrallardona et al., >65% SID Val:Lys>96% Jansman et al., % SID Val:Lys97% Barea et al., > 70% SID Val:Lys>103% Wiltafsky et al., % SID Val:Lys96-99% Trautwein et al., % SID Val:Lys99-103% Nemecheck et al., % SID Val:Lys96% Sloth et al., % SID Val:Lys96% Millet et al., % SID Val:Lys % Gloaguen et al., % SID Val:Lys106% Gaines et al., % SID Val:Lys96% Vinyeta et al., % SID Val:Lys103% Waguespack et al., % SID Val:Lys99-103% Lohmann et al., % SID Val>120% Reported information about the Val requirement Most work done in the last 10 yrs Almost all work concerns pigs < 30 kg Most requirements estimated by the linear-plateau model Reported requirements are around the NRC estimate

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T A Val deficiency reduces both feed intake and growth Barea et al., 2009

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Wiltafsky et al., 2010 Excess Leu aggravates the effect of a Val deficiency

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Meyer, 2012 Excess Leu aggravates the effect of a Val deficiency

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Excess Leu aggravates the effect of a Val deficiency Barea et al., 2009 Gloaguen et al., 2011

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T 16:00 fasting 8:30 Val+ or Val- test meal (70 g) ad libitum Val+ Test meal, 70 g Ad libitum intake of Val+, g Val-217 Val+252 9:3016:00 The pig rapidly detects a Val deficiency 16:00 fasting 8:30 Val+ or Val- test meal (70 g) ad libitum Val+ 12:3016:00 Gloaguen et al., 2012 (in press)

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T 46 dose-response studies since the 1950s Suitable for meta-analysis Criteria for selection: Supplementation with ≥ 4 levels of D-Ile or L-Ile Diet composition Intake and growth response Reported information about the Ile requirement

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Meta-design of Ile response studies

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Response to Ile supplementation Standardization of the responses: within-study response (Y-axis) relative to the NRC (1998) requirement (X-axis)

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Response to Ile supplementation Is there a response (P < 0.25)? 33  13

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Protein sources used to study the Ile requirement 27% of BCAA 3% of BCAA

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Response to Ile supplementation 1  9 32  4 Ile supply, % of NRC requirement Relative daily gain, %

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T The Ile requirement depends on the supply of the other branched-chain amino acids The NRC (1998) Ile requirement appears too high for diets without blood cells 50% SID Ile:Lys appears sufficient An Ile supply 10% below the requirement reduces feed intake by 15% and daily gain 21%

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T Introduction Expressing amino acid requirements and interpreting the response to the amino acid supply Responses to the supply of branched-chain amino acids (Val and Ile) How far can we go with precision protein? Conclusions Outline

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T IngredietsCereals – SBM – AACereals – AA CP, % L-Lys HCl DL-Met, L-Thr, T-Trp L-Val L-His, L-Ile, L-Leu, L-Phe L-Glu+++ L-Arg, L-Gly, L-Pro++ Gloaguen et al., unpublished How far can we go with precision protein? (12-22 kg BW pigs; 1.0% SID Lys)

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T IngredietsCereals – SBM – AACereals – AA CP, % Feed intake, g/d Gain, g/d450 b 454 b 442 b 358 a 420 b 451 b G:F0.58 c 0.56 bc 0.46 a 0.52 b 0.57 c How far go we go with precision protein? Gloaguen et al., unpublished

A L I M E N T A T I O N A G R I C U L T U R E E N V I R O N N E M E N T There is still a great potential to reduce the protein content in the diet Knowledge about the requirements (and responses) of secondary amino acids and nitrogen is limited There is variation among pigs in the response to a limiting amino acid supply: Some “safety margin” will be required to fulfill the needs of all animals A potential for precision feeding systems? Conclusions