"Interest in alternative feed ingredients spikes every five to six years, every time costs go up," said Professor Nick Dale of the University of Georgia at a panel on Alternative Feed Ingredients in Atlanta organised by Watt.

Professor Dale said, "The use of corn and soy in poultry feed didn't just happen. They are the main ingredients in the US, Canada, Argentina and Brazil because they lead to efficient production." Corn is a good energy source, and soy is a good protein, he said.

"Alternatives have to swim uphill," he explained.

Professor Dale considered that there are three types of alternative feed ingredients: those that have not been used before on a regular basis; those for which our knowledge of the nutrient composition is incomplete; and those for which the maximum inclusion rate has not been established.

New Ingredients

Some feedstuffs in this category are truly new ingredients, for example, biofuel by-products, which come in many different varieties. However, the majority are, in fact, used quite widely at low levels of inclusion, like bakery by-products. Quality control can be an important issue as they may also be very variable.

Some of these materials are new to a particular area. Professor Dale gave examples from Georgia state of sorghum, peanut meal, cottonseed meal and pearl millet. The last three have been little used in poultry feeds because of known anti-nutritive factors. Cottonseed meal, for instance, is not used at all in layer diets because of the risk of egg yolk discoloration.

Millet can be used in poultry diets but, as Professor Dale explained, "The quail people took it away from us as they pay more." So the price or availability of some materials may rule them out of consideration.

Ingredients with Incomplete Nutrient Composition

"Alternative feed ingredients need proper quality control from the outset to define the nutrient content for a particular source," said Professor Dale.

He went on to explain that while distillers dried grains with solubles (DDGS) can contain anywhere from 26 to 29 per cent crude protein, soya 44 and soya 48 are distinct products. The lysine content of tilapia meal from central and South America has been found to be anywhere between 3.0 and 3.9 per cent, making it impossible to incorporate in a least-cost diet without analysis of each sample.

Recognition of Inclusion Limits

Experience is required in setting limits of inclusion for unusual raw materials.

Professor Dale said that he has found peanut meal to be a very good ingredient with its carbohydrate fraction well utilised and a high arginine content despite a low lysine level.

The problem with peanut meal is the possibility of aflatoxin contamination. First recognised in 1962 as the cause of Turkey X disease, aflatoxins have negative effects on poultry health. But at what level of aflatoxin should peanut meal be rejected for poultry? Although there is no safe level of aflatoxins, Professor Dale recommends using no more than three parts per billion in the final feed. So a peanut meal of 100 ppb could be included at a level no higher than three per cent.

Taking Advantage of Opportunities

Professor Dale recommended being aware of niche uses for alternative feed ingredients. He cited the example of using cottonseed meal for heavy breeder pullets. The aim is to have these birds growing strongly and uniformly. The low lysine content of cottonseed meal - around half that of soya and only 60 per cent of it available - means the birds can be offered more feed and achieve these aims. Feeding this diet should cease at 16 weeks of age to ensure there are no problems with gossypol affecting the eggs during the breeding phase.

Professor Dale summed up, saying that new feed ingredients can be useful for poultry feeds. Caution is required regarding quality control, especially for those ingredients that vary widely from different sources. Nutritionists should keep in mind niche uses, although they may not necessarily led to significant costs savings.

"Don't wait for a crisis before you evaluate and gain understanding of alternative feed ingredients." warned Professor Dale in his conclusion.

February 2009