K N O W L E D G E C E N T R E

C AN 100% ORGANIC D IET S WORK FOR POULTRY?Jason Gittins from ADAS investigates

Organic diets for poultry mayneed to be formulated withoutany non-organic materials infuture.

This has focused attention on thepossible impacts of such a moveand in particular on raw materialavailability and cost and theimpacts on the health, welfareand performance of the birds. Inaddition, there may be widerimplications, due to changes inland use and crop rotation as wellas environmental considerations.

EU legislation currently allowsorganic poultry (and pig) farmersto use a limited proportion ofnon-organic feed material whereit is not possible to obtain feedexclusively from organicproduction. At present, thisallowance is widely utilised. Themaximum allowance for theinclusion of non-organic feedmaterials was originally set at10% in 2009. This was reducedto 5% in 2010 with an end dateof December 2014. In July 2014,it was announced that the 5%allowance would be extendedthroughout the EU for a further 3years i.e. until the end ofDecember 2017. Whilst this extension has removedsome of the time pressure fromrecent discussions, the issueremains relevant for the futureand also for any businesseswishing to pre-empt possiblefuture controls by assessing theiroptions at an earlier stage.

Nutritional ChallengesOf the 22 amino acids used inprotein synthesis in poultry, tenare ‘essential’, meaning that they

cannot be manufactured by thebird and they must therefore besupplied in the diet. For poultry,methionine and cysteine areregarded as the main or firstlimiting amino acids, followed bylysine. Any imbalance inessential amino acid supply couldresult in reduced productivity orgrowth, together with reducedfeed intake or utilisation. Inaddition, there could be impactson bird health and welfare.

Compared to conventionalrations, 95% organic rations arelikely to contain higher levels ofprotein, in order to meetminimum methionine and cysteinerequirements and a move from95% to 100% organic diets islikely to exacerbate this effect.Any nitrogen consumed by birdsin excess of their requirementswill be excreted. Litter qualitymay deteriorate with resultantimplications for health andwelfare and there are risks ofleaching and increased emissionsof nitrous oxide and ammoniafrom storage and spreading ofmanure.

In conventional poultry diets, soyabean meal is typically the mostimportant protein source,supplemented with syntheticamino acids to meet the requirednutritional specifications. Inorganic production, the goal is toobtain feed from the holdingwhere the animals are kept orfrom other holdings in the sameregion. The definition of ‘sameregion’, whilst inexact is unlikelyto extend to the use of soya whichis imported from non-Europeancountries. In addition, an

increasing proportion of soyabean meal is now derived fromgenetically-modified (GM) soyabeans which cannot be used inorganic rations, whilst chemically-extracted soya bean meal is alsoprohibited. Finally, EU organiclegislation prohibits the use ofsynthetic amino acids. Against this background,alternative protein sources haveto be used in organic production.Fish meal can be a potentiallyimportant material, helping tomaintain essential amino acidlevels without the use of excessivelevels of soya. However, thereare restrictions in terms of its use.For example, multi-species feedmills which also produce feeds forruminants are unable to use anyfish meal in rations produced forpoultry and pigs, but it is anoption for mills which producemonogastric (pig and poultry)rations only. If used, fish mealmust be derived as a by-productof fish for human consumption orfrom fisheries that have beenindependently certified assustainably managed. It isimportant that the quantity used isconsistent with avoiding the riskof taint developing in eggs ormeat. At present, theselimitations and high material costs generally mean that fishmeal is either not used at all or its use is restricted to high-specification diets and where feed consumption is low (e.g.chick feeds).

Health and Welfare ImplicationsDietary imbalances may causestress in laying hens, which inturn can lead to unwantedbehaviours such as feather

pecking. Dietary factors mayalso affect immune-competence,the bird’s ability to respond todisease challenges and to ensureeffective uptake of live vaccines.

There is a view that pullets andlaying hens fed on 95% organicrations are already on a‘nutritional knife-edge’ and that amove to 100% organic rations atpresent, using the same basic rawmaterials (particularly in theabsence of fish meal) wouldincrease the risk of health andwelfare problems occurring.

Formulating 100% OrganicRations for Pullets and LayingHensIn addition to whether fishmealcan be included or not, a keyconsideration is the range oforganic materials which areavailable for formulation andtheir quality and reliability. Forexample, organic maize glutenmeal (prairie meal) appears tooffer good scope for helping tomeet nutritional requirements in100% organic rations but atpresent, it is unlikely to beavailable in sufficient quantity tomeet all EU needs. Concernshave also been expressed over

quality consistency and the needfor importation from thirdcountries (such as China), whichagain is not consistent withregional sourcing. At individualfeed compounder level and alsofor on-farm ‘home mixers’,available storage capacity mayalso limit the range of rawmaterials that can be used.

Whilst noting these practicalconstraints, the following examplespecifications assume theavailability of a relatively widerange of raw materials, but notmaize gluten meal. Separateoptions are provided, accordingto whether fish meal can be usedor not.

Comparative pullet growerspecifications for conventional,95% organic and 100% organicfeeds are summarised asexamples in Table 1 below.

The table shows that in order tomaintain key amino acid levels,moving from 95% to fully organicrations without the inclusion offish results in a two-percentageunit increase in crude protein,from 18.7% to 20.8%. In theseexample specifications, this

increase in crude protein washowever associated with asubstantial increase in theinclusion rate of soya bean meal (from around 9% to 24%).Whilst the addition of fish mealwould enable the crude proteincontent to be reduced, additionalcosts would almost inevitably be incurred.

In the event that maize glutenmeal was available in addition to fish meal in 100% organicrations, the crude protein levelcould be reduced to around 18%, whilst still maintaining the required levels of essentialamino acids.

Example early layer rationspecifications for laying hens are set out in Table 2 on thefollowing page.

The table shows that in theabsence of fish meal, a movefrom 95% to 100% organic feedswould result in a further reductionin methionine, compared to anon-organic (conventional) feed.This is in spite of an increase incrude protein. The energy levelwould also be lower in theabsence of fish meal. As before,

Table 1: Comparison of nutrient levels in non-organic, 95% and fully organic replacement pullet grower feeds

MJ/kg

Non Organic95% plusfish

95% no fish100% plusfish

100%no fish

Metabolisable Energy (ME) % 11.50 11.80 11.80 11.80 11.73

Crude Protein % 15.0 17.9 18.7 18.3 20.8

Digestible lysine % 0.60 0.60 0.60 0.67 0.86

Digestible methionine % 0.30 0.30 0.30 0.30 0.30

Dig. methionine + cysteine % 0.55 0.55 0.58 0.55 0.60

Linoleic acid % 1.10 2.03 2.24 2.14 2.67

increased inclusion rates of soyabean meal would be expected,particularly in the absence of fishmeal. Soya inclusion could beapproaching 30% in 95% organicfeeds and close to 40% in fullyorganic feeds. Increased levels oflinoleic acid are likely to lead toincreased egg weight, which mayin turn be a contributor to stress.

In the event that maize glutenmeal was available in addition tofish meal in 100% organicrations, the crude protein levelcould be reduced to around 19%,whilst still maintaining therequired levels of essential aminoacids.

An additional consideration inrations for laying hens is the needto achieve an acceptable yolkcolour. In current 95% organicrations, small amounts of maizegluten meal are typically usedtogether with maize, lucerne andnon-solvent-extracted marigoldand paprika meals. In 100%organic diets, it is suggested thatonly maize and lucerne would beavailable in sufficient commercialquantities. If so, this could makethe achievement of an acceptableyolk colour more challenging.

Alternative Protein Sources andOther ApproachesMeeting essential amino acidrequirements is central to thechallenge of moving to 100%organic rations for poultry, hencethere has been increased interestin identifying suitable proteinsources for the future which canbe grown closer to home. Acurrent initiative, involvingresearchers in ten differentEuropean countries aims toproduce profitable, 100% organicfeeds for poultry and pigs.Within this, the use of a range ofmaterials is being considered,including unprocessed seeds ofgrass pea and sainfoin, musselmeal and algae. A number ofother recent and current studiesfocus on animal protein sourcesincluding insects and earthworms,in addition to other plant-originmaterials.

A recent study in Denmarkreported on the feasibility ofgrowing more climate-robustsoya bean cultivars in future, bothin southern and northern Europe.It was concluded that there ispotential to grow soya beans inEurope and to date, the levels ofprotein and methionine appear to

be at least similar to those foundin beans from USA, Brazil andChina. However, there is a needfor new cultivars and for thedevelopment of appropriate cropmanagement techniques inEurope to achieve a higher andmore stable yield.

Attempts are being made toenhance the methionine contentof plants such as lupins, beansand peas through plant breedingprogrammes, so that these canplay a more prominent role infuture organic rations for poultry.The use of specialist laying hengenotypes, such as those selectedfrom low-protein diets and moresuited to organic managementand feeding regimes is also apossibility.

Attention has also focused onenhancing the contribution madeby range land to the diets ofpoultry. This is consistent with theethos of organic systems and infavourable conditions,considerable amounts of herbagecan be consumed but seasonalvariations are inevitable. Thiscan make feed planning difficultand adversely affect foodconsistency and consumer appeal.

Table 2: Comparison of nutrient levels in non-organic, 95% and fully or-ganic laying hen feeds

MJ/kg

Non Organic95% plusfish

95% no fish100% plusfish

100%no fish

Metabolisable Energy (ME) % 11.50 11.50 11.50 11.50 11.30

Crude Protein % 15.3 19.0 21.8 20.7 22.7

Digestible lysine % 0.70 0.70 0.84 0.87 0.99

Digestible methionine % 0.35 0.34 0.34 0.33 0.31

Dig. methionine + cysteine % 0.60 0.61 0.65 0.59 0.60

Linoleic acid % 1.45 2.48 3.78 3.71 4.61

Whilst a move to 100% organicrations for poultry wouldundoubtedly present a challengeto nutritionists and producersalike, these initiatives offer hopefor the future. However, it will beimportant to fully understand theeconomic implications and toconsider wider issues such aslegislative constraints,environmental concerns andconsumer acceptance. n

AcknowledgementThis article is based on workcurrently being undertaken withinDefra Project OF0397 (100%Organic Diet Mixes forMonogastrics – Impacts on UKProduction) by ADAS, inconjunction with Premier Nutritionand St. David’s Poultry Team Ltd.This study will also be assessingthe economic implications of amove to 100% organic rations(based on likely changes in feedprices, flock performance andother factors) and the resultantenvironmental consequences. n

Jason Gittins, ADAS