Alternative raw materials in poultry feeds – an ever-diversifying pallet of options brings opportunities and challenges

In addition, the general consensus on what constitutes good poultry feed is being questioned. Does good feed just need to fulfil the nutritional requirements of the animal, or should other parameters be taken into account, such as sustainability and spreading risk to avoid sudden disruptions in availability or feed safety?

Sustainability and safety

In Europe, the issue of sustainability and responsible feeding has led to new concepts such as soybean-free feed and circular feed. Soybean-free feed usually means replacing SBM either wholly or partially with sunflower and rapeseed meals. These concepts have had varying success and often result in significant cost increases. One circular feed concept was investigated by researchers at LIFE Food for Feed (Life F4F) in Greece, part of the EU Action Plan for a Circular Economy. In this study, they investigated the possibility of using human food waste of varying compositions in poultry feed and successfully raised broilers with this feed. Despite this result, safety is crucial in any such waste-to-feed process. In the past, there have been reports of food-waste-based feeds being contaminated with viruses such as African swine fever (ASF). Furthermore, accurate information on the actual nutritional composition of these food wastes needs to be available in order to formulate recipes.

Continued use of SBM

Interestingly, there has been less discussion about soybean-free feed since the implementation of the EU's Regulation on Deforestation-free Products (EUDR). This is because SBM can be purchased from certified sources. Moreover, replacing SBM is costly, and with favourable raw material prices, SBM continues to be used at normal levels in conventional poultry feed.

Conventional broiler feeds are nutrient-dense feeds with a high protein requirement. Therefore, broiler feeds produced without, or with a minimum of, SBM, are more diverse in their composition. This is because available alternatives, such as sunflower seed meal and rapeseed meal, present various challenges, such as lower digestibility due to variability in crop yields, the presence of anti-nutritional factors (ANFs), and a different nutritional composition including a different amino acid composition.

Shift towards local sourcing

In African countries, similar changes are seen with an increasing trend towards using locally available raw materials. A strong motivator here is the need to avoid sudden disruptions in SBM imports from South America or wheat byproducts from Europe. Both layer and broiler feeds are diversified by using sorghum as an alternative to corn and wheat, rice bran instead of wheat bran and groundnut cakes, cottonseed and byproducts from ethanol production as alternative sources for protein. Here too, the alternatives present various challenges such as lower digestibility due to variability in crop yields, post-harvest processing, the presence of ANFs, and varying nutritional compositions.

Sunflower meals have been noted to vary between 24% and 41% crude protein. Which results in a lysine variation from 0.9% to 1.44% (!) This is because sunflower seed producers in different countries extract oil and sell their byproducts with varying quality of sunflower meals or even cakes (when oil has been extruded and not extracted by solvents). Protein, fat and fibre content in the by-products will vary greatly, depending on the extraction process used and the quality of the sunflower seeds themselves.

Diversifying the raw materials used in broiler and layer feed is a way of spreading risk. For example, in a standard SBM-corn based diet, the broiler starter feed will contain approximately 60% corn and 30% SBM. If the corn used is of lower quality than usual, either starch is reduced or mycotoxins are present due to poor storage conditions. In turn, much of the feed will suffer the same negative consequences. This will have a negative effect on animal performance as well. If however, only a smaller part of the diet is made up of corn, and the rest is made up of different raw materials, then the potential damage is much less.

When formulating with these alternative raw materials, one must keep in mind that there can be a lot of variation among different raw materials of the same nutritional category. Below is an overview of some commonly used raw materials as an example.

Impact on performance

Replacing corn one-to-one with wheat will result in significant changes in the complete feed for poultry. Even a partial replacement has an impact and the larger the inclusion of either material the greater the impact on the nutritional profile of a feed. See the table above for differences in content of macro nutrients, between corn and wheat.

When the corn in a corn-based diet is replaced by wheat, the nutritional composition of the feed will change. Neither corn nor wheat nor sorghum are included in broiler or layer feeds for their protein content, however, due to their relatively large inclusion rate, they contribute a significant part of their protein content to the feed. More interesting is the influence they have on the amino acid profile of the feed: corn contains 2.2 g/kg lysine and 3.6 g/kg valine while wheat contains 3.1g/kg lysine and 4.7 g/kg valine. In practice, this results in a 41% increase in lysine (when corn is replaced by wheat), which could disturb the ratios of lysine to other essential amino acids. For this reason, it is not advised to simply interchange raw materials, either fully or partially, without considering the actual nutritional composition of both the raw materials and the final feed.

Different raw materials also have different ANFs. In wheat for example, the non-starch polysaccharide (NSP) content is high. The right NSP enzymes need to be added  at the correct dosage to support the gastrointestinal tract in properly digesting these NSPs without viscosity challenges or preventing the bioavailability of essential nutrients.

Inclusion of NSPs and crude fibre-rich raw materials, like sunflower meal or cake, in layer feeds can result in wet litter and dirty eggs. Here, the right combination of enzymes has been proven necessary to reduce the viscosity of the digesta and mitigate or control wet litter and dirty egg challenges. Moreover, sunflower meals or cakes also have a different amino acid profile compared to SBM. Lysine content is relatively low, while other essential amino acids, such as methionine, are high when compared to SBM for example. This means that including sunflower products tends to reduce the lysine in feed thereby changing the amino acid composition of the feed.

Sorghum exists in different varieties: the well-known red and white types for example. These different varieties also have varying levels of tannins, critical ANFs in sorghum. Tannins have a negative impact on bird performance including reduced feed intake and poor nutrient absorption. In high amounts, they are known to have poisonous effects. Proper processing of the small grains, monitoring of the tannin levels and using a low-tannin variety are therefore strongly recommended when using sorghum in poultry feeds. Recently tannin-free varieties have been developed, realising a higher digestibility and therefore inclusion of sorghum as a serious alternative to corn and wheat in poultry feeds. 

So, how to use different raw materials in poultry feed?

Keep the different characteristics and nutritional values of different raw materials in mind. Remember that different raw materials will influence the feed both in terms of specific nutrients and the nutritional composition, but also in terms of anti-nutritional factors and further potential challenges. Talk to our poultry specialists to learn more about adapting the amino acid profile and mitigating challenges such as ANFs, when striving for more diverse and cost-efficient layer or broiler diets.