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Animal Health Notebook

Solve The Short-Energy Forage Problem

Monitor rumen pH to help decide when you need to add a little energy to a forage diet.


Forage tonnage and energy content from standing forage are the major limiting factors to profitability on the vast majority of North American livestock operations.

Properly managed cattle efficiently harvest grass, lay down litter, spread urine and manure, and build soil health and depth. Healthy, deep soil holds moisture and microbes and grows healthy, higher-tonnage plants. In other words, good grazing management solves the problem of tonnage.

In many areas, especially west of Interstate 35 almost all that is needed to get very good gains and production from cattle is sufficient forage and a little soluble natural protein, which I wrote about earlier this month.

East of I-35 in higher-moisture and more poorly mineralized soils, many locations have very low forage energy levels throughout the vast majority of the year. Cool-season grasses have a goodly amount of very soluble sugars for a few weeks each year, but washy grass and scouring cattle do not yield good gains or high profits. Tall warm-season prairie type grasses offer healthier gains but are often less productive in eastern pastures due to the competition from large amounts of cool-season plants and mistakes in pasture management.

Energy supplementation, in addition to soluble protein supplementation, becomes a necessity in many poorly mineralized environments with high annual rainfall or moisture. This is especially true when stocker calves, yearlings, or grass-finished cattle are the centerpiece of the operation.

That's why we have to supplement energy in order to get good gains and productivity in our Tennessee operation, even though we are growing huge amounts of diverse forage.

By energy supplementation, we are referring to sugars, starches, fats, oils, alcohols, and/or fatty acids. When added to the daily diet these increase caloric density.

Cattle do not digest forage. The microbes (bugs) in their rumen do the digestion and they work more efficiently on the cell wall starch of leaves from warm season plants. The microbes which eat forage cannot handle large amounts of energy supplement. But small amounts of additional energy supplement are beneficial. That means one pound or less energy supplement per 250 pounds of body weight. Higher amounts usually result in poorer digestion of the forage. Remember: The forage is what we are selling.

Corn is the king of energy supplements. Small grain seeds that have been processed and rolled will work. Molasses will work. So will apple cider vinegar. Also, very small amounts of vegetable and grain oils can be used successfully. The key is small amounts and really regular consumption.

The need for energy supplement can be monitored partially by checking rumen pH, or the acid-base balance. A pH of 7.2 is neutral and animals function best when their pH is neutral to slightly acidic (pH 6.8). A few years ago we began monitoring the urine pH of steers on grass. We started in mid-May when the steers were on pretty grass/legume/forb pasture. The cattle had had ample amounts of fresh grass daily and were staying full and content, however they were performing pitifully.

Urine pH’s reflect rumen pH’s, although not like a mirror. Our steers were running urine pH’s in the high 8’s and low 9’s in late May. This indicated a quite severe alkalosis. Alkalosis is the opposite of acidosis, but some of the clinical signs are similar. Both conditions are stressful and unhealthy to ruminants. Rumen pH of 6.8 to 7 on forage is the goal for healthy, efficient cattle gains. Urine pH should be close to that.

Be aware that unlike soluble protein, added soluble energy remains in the animal and affects performance for less than twenty-four hours.

After identifying the very high urine pH’s, we began adding molasses to the steers’ daily supplement and/or water. When we got to approximately six ounces of liquid molasses per 500-pound steer per day, the pH’s dropped to the low 7s

and performance and animal health increased dramatically.

The take home message is that small amounts of energy supplement and routine urine pH, manure, and animal monitoring can often yield much better performance and profitable gains in areas with higher rainfall (above 30 inches) or in wet seasons. This is especially true on immature cool-season and cereal-grain pastures. Nutritionist Mark Bader of Free Choice Enterprises says that he sees the same syndrome on washy wheat pastures in the late fall, winter and early spring every year when moisture is plentiful.

The energy supplement is used to tweak animal health and performance upwards a notch without reducing forage utilization. We have successfully used small amounts of molasses, ground corn, byproducts from cereal grains, apple cider vinegar, glycerin, and other vegetable and grain oils. We have used combinations of the above and different delivery systems into our steers. Again, the key is small amounts to all the animals, plus monitoring.

Remember the bottom 30% of the cattle herd needs the supplement the most. We use salt, ag lime and/or sawdust to limit consumption.

Pretty pastures often need a little tweaking to maximize black ink. Lush annual pastures always need help.

Guidelines for checking pH

Check urine pH using pH paper at least once weekly.

Do not allow pH to go below 6.8.

Consider this mix in order to maximize energy supplementation to cattle on forage:

• Ground corn – 2 pounds per 500 pounds of body weight
• Rolled small grains – 2 pounds per 500 pounds of body weight
• Hominy feed – 2 pounds per 500 pounds of body weight
• Wet molasses – 10 ounces per 500 pounds of body weight
• Soybean or vegetable oil – 4 ounces per 500 pounds of body weight
• Apple cider vinegar – 8 ounces per 500 pounds of body weight or 1 gallon per 150 gallons of water


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