Remove The Risks Of Feed Wheat

Wheat has often taken a backseat to barley and corn in feeding beef cattle in western Canada. The latter grains have been in relatively good supply and more economical to put on good weight gains. Furthermore, compared to wheat, barley and corn do not carry a misleading reputation as a “hot grain” for cattle. Therefore, the majority of wheat fed to livestock in the prairie provinces has been traditionally shipped to poultry and hog farms.

However, with the recent wet summer and delayed harvest, an ample supply of competitively priced feed wheat is just around the corner. Wheat can be an excellent nutritious feed for cattle, but interested producers should take precautions to remove its feeding risks.

The nutrient profile of wheat makes it a high protein — high energy feed ingredient amongst the cereal grains and corn. On a dry matter basis, the crude protein content of wheat is about 13 to 13.5 per cent compared to 10 to 11.5 per cent for barley and eight to nine per cent for corn. Its energy value is measured at 89 per cent TDN, while barley and corn are rated at 84 and 90 per cent, respectively.

Further analysis shows it has a comparable starch content (contains most of the grain’s dietary energy) to other common grains; wheat, 62 to 65 per cent; barley, 50 to 60 per cent; and, corn, 70 to 75 per cent. While it appears wheat has a lower starch value than corn, wheat starch is rapidly digested in the rumen with less starch travelling to the small intestine, thereby supplying a more readily available form of energy than corn. It is estimated about 90 to 95 per cent of wheat starch is degraded in the rumen compared to 60 to 75 per cent of corn starch degradation.

Such rapid starch digestion in the rumen makes feeding wheat a little tricky compared to barley or corn. There’s a risk of rumen acidosis developing when either feeding very high levels of wheat or rapidly introducing wheat rations to hungry cattle. It is particularly true when stocker or backgrounding cattle are moved from a forage-based diet onto a more intense grain-based one.

As the amount of forage in these growing-to-finish diets decrease, the acid-buffering ability of each animal also decreases, with potential for a build-up of dangerous digestive acids. As a result, the pH of the rumen contents may become excessively acidic (fall below a pH of 6.0), which could adversely lead to lower feed intake, depressed weight gains, rumenitis (rumen inflammation), hoof problems and increased risk of liver abscesses.

To prevent either sub-clinical or acute acidosis from occurring in cattle fed high-feed wheat rations, several broad feeding guidelines have been established. For example, in moderate to high grain rations (50 per cent or more) for growing cattle, wheat should be fed along with other lower starch or more fibrous grains and be limited to 40 per cent of the total diet on a dry matter basis. As well, supplemented feed wheat should be limited to 0.4 per cent to one per cent of the cattle’s bodyweight.

Both suggestions tend to be subjective, because you have to factor in the amount of forages also being fed. With more forages, more feed wheat can be safely fed. One mid-U. S. field trial showed 700-lb. feeder steers fed 2.5 to 2.75 lbs. of wheat had no adverse effects on a forage-based diet. This amount could be safely increased to about 4.5 lbs./per head/per day, when hay intake was also increased. In this case, wheat was coarse rolled (versus fine-grind) to avoid rapid degradation in the rumen which could lead to acidosis.

Aside from preventing acute acidotic digestive upsets, producers should always be aware that wheat does predispose cattle to liver abscesses, which is acidosis related and particularly for those cattle reared on aggressive high-energy grain rations. Fortunately, the incidences of liver abscesses in high grain fed cattle can be controlled up to 70 per cent by medicating rations with tylosin phosphate.

One last related issue, when feeding wheat to beef cattle, relates to basic grain quality. The wet summer and harvest conditions allowed for two adverse challenges that could significantly lower feed wheat’s otherwise excellent nutrient value, namely, vomitoxin contamination and the prevalence of sprouted grain.

While research shows cattle can tolerate 10 to 21 ppm vomitoxin contaminated grain without adverse effects on health, vomitoxin does affect wheat kernel quality, which is synonymous with its dietary energy content. Producers including vomitoxin wheat into feeding programs should visually inspect a number of wheat samples beforehand (look for shrivelled and white to pink seeds) and then measure the grain’s bushel weight, since heavily contaminated grain (greater than 3.0 ppm vomitoxin) tends to have lower bushel weight and thus lower energy values.

Similar to vomitoxin, sprouted wheat surveys taken from the swath or standing wheat have shown graduated lower bushel weights, which corresponds to a higher percentage of sprouted kernels (NDSU, 2000). Related studies also showed feedlot cattle performance was not affected when sprouted wheat replaced regular wheat in the growing-finishing diets. Although such trials might validate feeding sprouted wheat to feedlot cattle, we have to realize there are varying degrees of sprouted grain, from slight root development to nearly empty kernels showing green sprouts.

Knowing the quality of feed wheat before using it in growing beef cattle diets is no different than testing the quality of other traditional grains such as barley or corn. With this information, it becomes a matter of taking a few precautions to feed it safely. No doubt, feed wheat can put profitable weight gains on growing beef cattle. It’s no longer a “hot grain” for beef cattle, but one that sizzles.

PeterVittiisanindependentlivestock nutritionistandconsultantbasedinWinnipeg. Toreachhimcall204-254-7497orbyemailat [email protected]

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Peter Vitti is an independent livestock nutritionist and consultant based in Winnipeg. To reach him call 204-254-7497 or by email at [email protected]

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