The nutrient composition of maize and wheat differ significantly. Maize typically contains around 8% protein and 3350 kcal metabolisable energy (ME) per kg. In contrast, wheat is higher in protein (10 – 14%) and lower in ME (3100 kcal/kg). Therefore, the grains need to be analysed for protein and properly formulated into the diet for broilers and breeders. When introducing an alternate grain such as wheat this should be phased in slowly, typically 10% increments replacing maize over a 3 or 4 week period until the target wheat level is reached.
An important issue with wheat is the composition of non-starch polysaccharides (NSP’s). Wheat is particularly high in soluble arabinoxylans which can have anti-nutritional effects, such as increased gut viscosity, on digestion and bird performance. The typical NSP composition compared with maize and soymeal is shown in the table below.
The relative content of NSP components (%) in feed ingredients
The composition of NSP’s varies widely. Generally, arabinoxylan, B-glucan and cellulose are important in cereal grains while pectins, cellulose and oligosaccharides are significant in oilseeds meals. Adapted from Ward (2014).
Although a combination of maize and wheat greatly reduces the risk of NSP-related performance effects, it is important to include a xylanase-based feed enzyme in diets which contain more than 20% wheat. The xylanase enzyme breaks down the arabinoxylans in wheat (and other grains), removes the anti-nutritional effect and improves ME and performance of the diet.
Xylanase enzyme is stable under normal steam pelleting conditions.
Wheat can be highly effective in broiler diets in combination with maize. Recommended inclusion levels would be 20-40% of the diet depending on least-cost diet formulation values for each grain. Clearly, wheat needs to be priced competitively and reduce feed cost compared with an all-maize diet.
Wheat can also be used in Parent Stock diets, both rearing and production. The level of inclusion is recommended up to 20%, keeping in mind incremental changes in the grain composition so as not to affect gut health and performance. Xylanase enzyme is recommended in all cases.
Your nutritionist is best positioned to help evaluate wheat versus maize cost/benefit in the diet formulation process and ensure the above performance conditions are put in place.