Supplementation for fall grazing livestock - supporting a rancher’s renewable resources


VALLEY — Ranchers have two primary renewable resources they utilize. One is the forage they graze and the other is the calves, lambs or other market products they produce. 

The forage resource supports the livestock resource by providing for the nutrition needs of the animal. Sometimes, the forage resource is lacking some of the nutritional needs for the animals. Supplemental feeds provide additional nutrients to support the available forage. Existing forage is not taken away to make room for the supplemental feed.

On average, almost 40 percent of a ranch’s operating costs in cow-calf operations are related to nutrition. Harvested, purchased or concentrate feeds make up most of that cost. This makes the nutritional program a major target to reduce costs. 

A ranching program is basically a forage harvesting enterprise. Cows or other livestock are used to harvest available forage. The calves and cull animals are the income to support the forage harvesting enterprise. 

When forage production and grazing management is going good, few purchased feeds are needed. There are times however, when forage production and quality don’t meet the cow’s needs. Supplementation will then make up for the nutrients that are short. The supplements can help increase the body condition of the animal if it’s needed. 

Even though forage quality is often lower in the fall than spring and summer, it will often be all the nutrition a cow needs. With some grasses or grazing plans, supplements are needed to meet the cow’s needs.

Most ranchers have a spring calving program. With this program they usually wean calves in the fall. Once calves are weaned it is easier to increase the body condition of the cows if it’s needed. The need to increase body condition increases nutrient needs. This may increase the need for supplemental feeds.

Ranchers need to determine when and if supplemental feeds are needed. Step one of the process is to determine the nutritional needs of the animal. There are many charts that will show an animal’s needs based on the reproductive stage of the female. The nutritional status of the female is closely correlated to reproductive performance. If the feeding program is short on a nutrient it can have a severe impact on pregnancy or calving rates.

Step two is to estimate the nutrients the animals receive from the forage. Tests can be done to show the actual forage value but few producers spend the money. The forage quality will change as the seasons progress. This means an additional round of testing would be needed every few days.

Step three is to subtract the animal needs from the forage available. If there is extra forage, then no supplements are needed. If the animal needs are not met, then supplements should be added to the diet.

Step four is to determine which supplements are available that will meet your animal’s needs.

Often in the fall and winter, ranchers will use a protein and energy supplement.  These are the two nutrients most often short. Mineral supplements are often available to an animal year round.

Once the four steps are complete, then a rancher will select the supplement that works best with their management style and will fill the nutrient needs of their livestock.   

For more information on this and other topics of interest to you, contact the San Luis Valley Extension Office at 719-852-7381 or email Marvin Reynolds at [email protected]    

Extension programs are available to all without discrimination, Colorado State University Extension, U.S. Department of Agriculture and Colorado counties cooperating.

Caption: Supplemental feeds provide additional nutrients to support available forage. Courtesy photo


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