Can you raise cattle solely on forages?

When raising animals that are designed to exist on a forage diet, producers naturally want to use that to their advantage when managing their cattle. But is a solely grass diet really enough for cattle in the Ozarks to survive and thrive?

Dr. Eric Bailey, University of Missouri Extension Beef Nutritionist: “The question of cows surviving on grass alone is a fascinating one. Is there a world where that is possible? My answer is yes, but it is not going to happen under the current production model. To survive on grass alone would require significant reduction in stocking rate. Think 5 to 6 acres per cow (at least), instead of 3 acres per cow that most stock at.”

Many producers have been taught protein supplementation is the key to beef cattle nutrition, but that’s not always true.

“Our forage/livestock systems are most frequently deficient in energy, not protein,” Bailey said. “Our production system is based upon cool-season perennial grasses, which have greater amounts of protein than western production systems, which are based on warm-season grasses. To me, that means we need to think about supplementation strategies focused on getting more energy in the cows. Corn, soyhulls, wheat middlings, gluten pellets, distillers’ grains, higher quality forage – those are the supplements we should focus on. My preference in supplements is the most cost effective of them at a given time point. The cost of these commodities fluctuates throughout the year. Take advantage and buy individual commodities when possible, even if you’re buying small quantities. Most importantly, do not overlook corn as a supplement. It is energy-dense and highly palatable. Poor quality hay can be “upgraded” significantly by 5 to 6 pounds of corn per cow per day. That will cost you 45 cents per cow per day. Supplements should be provided when grass gets too short (less than 4 inches average height across the entire pasture, not just the tall plants they refuse to eat).”

Other good times to supplement are when cattle nutrient requirements are high. Calving to breeding is the peak nutrient requirement period.

“If you calve in the winter, before fescue takes off, plan to supplement those cows.” Bailey explained. “Going into the breeding season losing weight makes it more difficult for cows to rebreed. Moving calving later in the winter (March/April) improves nutrition but may stretch the breeding season into the heat of the summer. This is one of the reasons fall calving seems to work so well in Missouri. There is high quality forage from September onward, and moderate temperatures. The biggest issue we run into with fall calving is running out of high quality “stockpiled” forage and switching to feeding poorer quality hay. Try to stockpile as much forage as possible and graze as far into the winter as possible if fall calving.

A mineral supplement should be kept out all year. Think of the supplement as an insurance policy, not a means of increasing pregnancy rate in cows or weaning weight in calves. Do not spend too much money on insurance you do not need.”

Dr. Shane Gadberry, University of Arkansas Ruminant Nutrition Specialist: “Our production expectations usually exceed what we often achieve from grass alone. When I think of supplements that should be offered, the first that comes to mind is mineral and vitamin supplements. Grazing systems research suggests that forages can vary in mineral content for a number of reasons, including plant type and maturity, and soil nutrient content. If plants are high in one mineral, it may be low in another or poorly utilized by the animal just because of the way minerals interact. Vitamin content of grass can also depend on whether the grass is growing or has been harvested and stored for later feeding. So, my answer is grass isn’t enough when it comes to minerals and vitamins. Forage deficiencies related to salt, phosphorus, and magnesium can grossly impact herd production.”

Certain areas may also be prone to trace mineral deficiencies like selenium. County Extension agents and veterinarians can provide recommendations on how to assess mineral status of the cow herd and what minerals may be a local problem.

“Another nutrient that can be a problem is protein in truly native pastures, particularly in the fall,” Gadberry said. “We often find producers using supplemental protein in the fall to improve forage digestion. I advise producers to collect forage samples to see if the supplemental protein is really needed. With improved grass species and fertilized fields, there is usually enough protein for the amount of digestible organic matter present. I often look for a total digestible nutrient to crude protein ratio of less than 6:1. If the ratio is greater than 6:1, protein will likely help forage utilization. If the ratio is less than 6:1, the cattle will still respond to the extra nutrients from supplement but not likely from improved forage consumption.”

The last issue to discuss when asking if grass is really enough, relates to forage digestibility. This problem is greatest during the winter when the herd is being fed a harvested grass while nursing a calf.

“Our forage test results indicate about 70 percent of hays do not meet the energy needs for lactation,” Gadberry said. “What we find is when cattle producers use forages that complement one another and extend the grazing season, those operations become less reliant on supplement protein and energy feeds. For those herds, grass is mostly enough but the need for a complete mineral supplement remain.”

Andy McCorkill, MU Extension Livestock Specialist: “With management and the proper genetics, in our environment you could well maintain your cows on a forage diet year-round a lot of the time. First, you have to have enough forage to be able to fit the bill, then you have to have cows that will maintain on it. We use Body Condition Scoring as a tool to evaluate a cow’s nutritional status. If the herd is losing flesh, it’s time to supplement with some better feed. This is mostly a problem in early lactation, when the cow’s nutritional requirements are the highest. On the 1 to 9 scoring system, we like to see the herd maintain a 5 to 7 score.”

McCorkill went on to say mature cow herd nutritional requirements compared to typical fescue pasture are in line much of the year so grass management is more important than managing quantity.

“A managed grazing system to allow for the pasture to rest and regenerate is a good first step,” he said. “Growing stock, on the other hand require a little better management to meet their nutritional requirements for acceptable growth. Grazing grasses in the boot stage, and before they get overly mature, is a must. As plants mature and produce seed, they get more fibrous, reducing energy levels. No matter what species or age, a diverse forage base will help ensure there is something of quality and quantity there for the herd to ear much of the year. The key is matching all the variables up for year-round success.”


Please enter your comment!
Please enter your name here