Question from Thomas Whatley:
“Most of the literature says that clover planted in fescue forage will help to negate the bad effects of the fescue grass. Will feeding legume hay such as alfalfa have the same positive benefit?”
Answer from Monty Kerley, PhD, University of Missouri beef nutrition specialist
I believe most would conclude that legume interseeding of pastures reduces effects of endophyte-infected tall fescue by diluting consumption of the toxin in the fescue plant. If a legume is available to the animal, grazing cattle typically select for the legume which does not contain toxin present in endophyte-infected tall fescue. The end result is less toxin is consumed, and therefore less toxin is present to reduce growth performance.
The same would be expected if tall fescue hay, or any supplement that did not contain the toxin were fed. My guess is that a difference between interseeding a legume in pasture and feeding legume hay would be that in the grazing situation, all animals would have access to the legumes. If sufficient space is not available for all animals to access the legume hay, then animals not consuming the hay would not benefit.
Nutritionally I would expect the same beneficial response, care would have to be taken to make sure all animals could gain access to the legume hay.
Link to photo of Kerley: http://animalsciences.missouri.edu/faculty/kerley/
Answer from Shane Gadberry, PhD, Extension beef specialist, University of Arkansas
We have to start by thinking how the clover negates the bad effects of Kentucky 31 toxic fescue. The benefit is not from a chemical/physiological response within the animal due to some compound within the clover being able to block or tie-up the toxins.
The benefits of clover are:
1. It is a cool-season legume that grows during the same times of year as fescue.
2. Toxins in fescue reduce intake, so having another forage available that is of high quality will help overall nutrient intake.
3. Cattle will seek out non-toxic plants - so clovers will help support greater performance as they consume less fescue.
4. Because clover fixes nitrogen, using it in conjunction with cool-season grasses can help reduce fertilizer costs.
So, will alfalfa hay have the same positive benefits? The alfalfa hay benefit would be due to:
1. Cattle have something to eat other than toxic fescue.
2. Moving feeding locations around the field will help recycle the nutrients in alfalfa, including its higher nitrogen content compared to grass hays, back to the field.
Then, what we decide to do is based on economics. The reason we continue to grow K31 fescue is because it is persistent, easy to maintain, and provides an abundance of forage during the spring and fall. Feeding hay is very expensive, so in the long-term, it would be more cost effective to focus on managing pastures to minimize toxic fescue problems by incorporating clovers, possibly replacing some of the toxic stands with a new non-toxic, endophyte-infected fescue, and evaluating the mix of cool-season and warm-season forages to provide relief during the summer months.
In the short-term, if you are having severe fescue toxicity problems then you may want to get them off the fescue and onto hay, such as alfalfa or a warm-season grass hay.