written by: dr. jacquie jacob, university of kentucky
wheat (triticum aestivum) is often used in poultry diets in western canada and parts of europe. the husk of wheat detaches from the grain during threshing (in conventional barley and oats, the husk remains attached), reducing the grain’s fiber content. the energy content of wheat is 94% to 96% that of corn. wheat is higher in protein and the amino acids lysine and tryptophan than corn. wheat contains gluten, which is advantageous in the making of pellets because it eliminates the need for pellet binders.
wheat varieties are categorized according to three classifications.
- wheat varieties can be classified as soft or hard depending on their gluten content. hard wheat varieties tend to have high protein content, while soft wheat varieties have a high starch content. durum wheat, used most often for human consumption, is the hardest of the wheat varieties.
- wheat types are also classified as red or white depending on the grain color.
- the third classification reflects the variety’s growing season. winter wheat, planted in the fall, becomes dormant to tolerate winter temperatures until spring. spring wheat lacks the dormancy capability and can be planted only in the spring.
different wheat varieties contain different types of starches, some of which are difficult for the foregut to digest. these starches become food sources for lower gut bacteria that may form waxy pbeplayapp网页 and lead to sticky fecal material. the use of supplemental feed enzymes helps alleviate this problem in chickens.
recently there has been interest in feeding whole grains to poultry. some experts believe feeding whole wheat feeds to chickens improves their digestive tracts, increasing the birds’ ability to resist coccidiosis challenge. including a high percentage of ground wheat in feed can result in flour buildup in feeders, so producers who do so must take extra care to prevent mold contamination.
table 1. nutrient content of hard and soft wheat (source: feedstuffs ingredient analysis table: 2016 edition of the feedstuffs reference issue, by amy batal and nick dale, university of georgia)
| nutrient | hard | soft |
|---|---|---|
| dry matter, % | 88 | 86 |
| metabolizable energy, kcal/kg | 3170 | 3210 |
| metabolizable energy, kcal/lb | 1440 | 1460 |
| crude protein, % | 13.5 | 10.8 |
| methionine, % | 0.25 | 0.14 |
| cysteine, % | 0.30 | 0.20 |
| lysine, % | 0.40 | 0.30 |
| tryptophan, % | 0.18 | 0.12 |
| threonine, % | 0.35 | 0.28 |
| crude fat, % | 1.9 | 1.7 |
| crude fiber, % | 3.0 | 2.8 |
| ash, % | 2.0 | 2.0 |
| calcium, % | 0.05 | 0.05 |
| total phosphorus, % | 0.41 | 0.30 |
| non-phytate phosphorus, % | 0.12 | 0.11 |
wheat by-products
- wheat bran consists mainly of the outer coatings of wheat kernels.
- wheat red dog, sometimes referred to as “light shorts,” is a product from the tail of the mill that consists mainly of the aleurone layer with small pbeplayapp网页 of bran, germ, and flour.
- wheat middling consists of fine pbeplayapp网页 of bran and germ, with very little red dog.
- wheat shorts consist of bran, germ, flour, and tailings.
- wheat screenings consist of thin, broken, and shrunken wheat kernels, weed seeds, and other contaminants, including straw, chaff, and dust. commercial products should have at least 35% grain, less than 8% small weed seeds (for example, wild and domestic mustard, flax, rapeseed), and not have more than 8% wild oats.
table 2. comparing the nutrient content of wheat and wheat by-products
| ingredient | dm | energy | cp | ee | cf | ca | met | lys |
|---|---|---|---|---|---|---|---|---|
| wheat, hard | 88 | 3170 | 13.5 | 1.9 | 3.0 | 0.05 | 0.25 | 0.40 |
| wheat, soft | 86 | 3210 | 10.8 | 1.7 | 2.8 | 0.05 | 0.14 | 0.30 |
| wheat bran | 89 | 1300 | 14.8 | 4.0 | 10.0 | 0.14 | 0.20 | 0.60 |
| wheat shorts | 89 | 2530 | 16.0 | 4.2 | 6.0 | 0.11 | 0.18 | 0.78 |
| wheat germ meal | 89 | 2820 | 25.0 | 7.0 | 3.5 | 0.01 | 0.42 | 1.37 |
| wheat middlings | 89 | 2090 | 15.0 | 3.6 | 8.5 | .015 | 0.12 | 0.70 |
| wheat grain screenings, #1 | 89 | 2780 | 14.8 | 2.6 | 6.2 | 0.18 | 0.17 | 0.40 |
| wheat grain screenings. #2 | 92 | 2650 | 12.5 | 3.9 | 7.6 | 0.13 | 0.12 | 0.48 |
dm = dry matter, %; energy = kcal/kg; cp = crude protein, %; ee = crude fat (ether extract), %; cf = crude fiber, %; ca = calcium, %; met = methionine, %; lys = lysine, %
(source: feedstuffs ingredient analysis table: 2016 edition of the feedstuffs reference issue, by amy batal and nick dale, university of georgia)