All indications point to a bumper cereal crop this year. Wheat, in particular, appears to be in one of its best years, with several growers reporting up to double their normal yield. As it happens, in all cases of such abundance, ample quantities of soft and hard wheat will overflow to the animal feed industry. This bounty will reach regions and animal producers who have not previously used wheat, at least in large enough concentrations in their feeds.
And, unlike corn, the more traditional staple cereal for broilers, wheat has a few extra quirks that require attention at formulation, manufacturing and handling of feed containing more than 30 percent of this cereal. The discussion below is meant to highlight these nuances that must be addressed by a nutritionist after examining the wheat at question.
1. Wheat increases gut viscosity
The high presence of non-starch polysaccharides (NSP) in wheat increases gut viscosity. Pentosans (arabinans and xylans), in particular, can absorb 5 to 10 times their weight in water. Assuming an average quality wheat contains about 5 percent NSP, this means a diet with 30 percent wheat will have the ability to absorb and retain up to an extra 15 percent water. This has negative effects on litter quality and nutrient digestibility. To this end, it might be beneficial to consider an enzyme that destroys the undesirable NSP fraction. However, finding an enzyme that actually works the way it claims appears to be more difficult than it should be.
2. Protein in wheat is extremely variable
In general, wheat contains more protein than corn, and hard wheat contains more protein than soft wheat. In practice, however, the actual concentration of wheat can be extremely variable. In extreme cases, wheat protein concentration can be 100 percent different from the average value given in books. Not only growing conditions (weather, soil, fertilization) affect protein levels, but also the specific wheat hybrid markedly affects actual levels. To this end, it is even more important than in the case of corn to subject incoming batches of wheat into chemical analyses. For large operations, it is profitable to separate and store incoming wheat loads into at least two storage bins: one for above average and one for below average protein wheat. Feed formulation can then be adjusted accordingly, with obvious benefits in terms of feed cost and uniformity in animal performance.
3. Wheat gluten protein is pasty
Grinding wheat too finely is not required in broilers. In fact, the opposite is true. Not only do broilers not benefit from a finer grind, like pigs do, but also their digestive system is impacted negatively. In addition, wheat gluten is a sticky protein that causes feed to have reduced flowability; it tends to stick onto beaks causing problems in the bird’s feed intake ability. A medium to coarse grind size is preferable. In fact, it is even possible to feed whole wheat in addition to a supplemental feed, but this is a totally different approach.
4. Wheat has virtually no bioavailable biotin
The bioavailability of biotin in wheat is virtually zero, compared to about 75 percent in corn. Other cereals also have low bioavailability, such as barley and sorghum (10 and 20 percent, respectively). Biotin is a vitamin that acts as a coenzyme essential in lipid, protein and energy metabolism — in other words, it plays a central role in metabolism. Molds, choline chloride, trace minerals, and feed rancidity also destroy biotin. Biotin deficiency results in a number of clinical symptoms with the most obvious being leg disorders (perosis). More practically, biotin deficiency reduces lesion healing leading to reduced footpad heath, especially in wet litter conditions. Diets based on corn usually benefit from the addition of about 100 micro-grams biotin per kilogram finished feed. When wheat is the main cereal, it has been reported that up to 300 micro-grams supplemental biotin might be required. Biotin, however, is a very expensive vitamin and, as such, it is best left to the discretion of the nutritionist to decide how much to use based on actual wheat usage.
Field reports indicate that diets based on wheat favor the development of necrotic enteritis.
5. Necrotic enteritis is favored by wheat
Field reports indicate that diets based on wheat favor the development of necrotic enteritis. This is probably a combination of increased viscosity and fine grinding that appear to provide a desirable medium for the proliferation of bacteria. Indeed, coarse grinding or roller-milling of wheat results in reduced incidences of necrotic enteritis. The problem is exacerbated in nutrition programs that have removed growth-promoting antibiotics from broiler feeds. Nevertheless, necrotic enteritis is a multi-factorial problem, only partially addressed through nutritional interventions.
6. Wheat makes harder pellets
This is old news for feed manufacturers, but it is perhaps interesting to consider removing an additive pellet binder when increasing wheat concentration in broiler feeds. In fact, increasing pellet durability (and consequently crumble size) and reducing the amount of fines is a desirable trait for broiler feeds, but extra-hard pellets will take more energy to crumble at the feed mill.
7. Mycotoxins in wheat can be different compared to corn
If corn is the usual cereal in an operation, switching to the unknown wheat entails a further consideration. Wheat is affected by similar molds but at a different way compared to corn. Thus, the presence and levels of most known mycotoxins might be different in wheat than in corn. To this end, it is best consulting with your supplier of anti-mycotoxin agents to test your incoming wheat and decide which product is best suited for your particular profile. Indeed, such advice is sound for all cereals at all times!
Wheat is an excellent cereal that can outprice corn in traditional broiler formulas, especially in years of bumper yields. But, it takes some extra consideration at formulation, manufacturing, and handling of wheat-based diets to make the transition smooth and problem free.