FEED Business Worldwide - June 2012

 

Using wheat as an alternative to corn in Southeast Asia  

 

by Alexandre Péron1 and Ahmed Amerah²

¹ Danisco Animal Nutrition, Singapore

² Danisco Animal Nutrition, UK

 

 

Corn is usually the main ingredient used in pig and poultry feeds produced in Thailand and other parts of Southeast Asia. What happens though when prices are high and there are concerns over corn supplies? Having a strategy in place to enable replacement of one type of feedstuff with another in animal diets is an excellent way to alleviate inherent market volatility risks in raw material prices and supply. Replacing all or some of the corn in diets with imported wheat can present an interesting opportunity in order to reduce feed costs and maintain profitability. Being prepared with the correct information and feed additives, when implementing such a strategy, will ensure a successful, productive and profitable outcome.

 

The inclusion of high levels of wheat (>50%) in feed formulation is a very common practice in northern Europe, Canada and Australia. However, in Asian markets, limited experience in dealing with wheat as a feed ingredient leads to some concerns over its use in livestock feeds. This is mainly related to the fact that wheat's inherent nutritional value varies more than that of corn. Therefore, its use represents a risk in terms of maintaining consistent animal performance. However, the use of enzymes in the diet can alleviate and cancel-out many of the perceived risks of using wheat to replace corn.

 

 

 

As shown in Table 1, wheat has more protein than corn, but it contains less starch and more non-starch polysaccharides. As a result, wheat digestible or metabolisable energy value is lower than corn.

 

 

Protein and amino acid levels in wheat vary more widely than in corn. In addition, besides having a higher protein content, wheat also has a different amino acid profile than corn (e.g. it contains approximately 30% more lysine). As a consequence, diets formulated with wheat should be balanced on a digestible amino acid basis, not a crude protein basis.

 

Arabinoxylans represent the main non-cellulosic non-starch polysaccharides (NSP) component of both grains. However unlike corn, wheat contains significant amounts of soluble NSP. High levels of soluble NSP are responsible for increased gut viscosity and lead to reduced nutrient utilization and animal performance (see figure 1). They can also result in increased microbial proliferation in the gut and poor litter quality (Choct and Annison, 1992; Steenfeldt, 2001; Carré et al., 2002; Barletta, 2003).

 

Swine have more dilute digestive contents than poultry, and this characteristic appears to make them less sensitive to the negative effects of feed wheat's viscosity. Therefore, pig diets may allow for higher inclusion levels of wheat than can be tolerated in poultry feeds. Nonetheless, high soluble NSP levels have been shown to be an exacerbating factor in the development of non-specific colitis in pigs.

 

For both animal species, the insoluble NSP fraction of wheat and corn is responsible for nutrient encapsulation, leading to lower accessibility of starch and protein. In addition, the water-holding capacity of insoluble NSP-based fibre reduces both the availability of water-soluble nutrients and feed intake itself. Importantly, all these issues can be easily alleviated by the use of an appropriate NSP-degrading enzyme.

 

Regarding essential minerals, wheat contains more phosphorus than corn and, more importantly, it has a greater proportion of available phosphorus.  Moreover, endogenous phytase activity is higher in wheat grain than in corn.