The source of lysine in your ration may or may not be something you’ve given serious consideration to. However, lysine is one of the first two limiting amino acids in a lactating cow’s diet and plays a critical role in milk production potential.

Lysine is available to the animal through feedstuffs, with blood meal as one of the more common sources of lysine in the diet. The rising price of blood meal is giving dairy producers and nutritionists a reason to look at rumen protected lysine products. That’s according to Dr. Andy Mueller, manager of dairy nutrition and technical support with Purina Animal Nutrition in Minnesota.

Selecting an alternative lysine source isn’t as easy as it sounds though, says Mueller. “Not all lysine sources are created equal and in the last several years the market has been flooded with protected lysine sources. As a result, determining the best source doesn’t come without some serious evaluation.”

In his experience, Mueller says, too often dairy producers and nutritionists will look at price per ton when evaluating alternative lysine sources, but that’s not the only thing to look at.

“What are you getting per ton is the better question to ask,” he says. “Evaluating cost per gram of metabolizable lysine may provide better insights into what you’re getting.”

For example, one source may contain 44 percent metabolizable lysine, with 200 grams per pound and costs $3.37 per pound, which figures out to be $0.017 per gram of metabolizable lysine. In comparison, another source with 7.4 percent metabolizable lysine, containing 34 grams per pound, costs $1.43 per pound, or $0.031 per gram.

“The cost per gram of metabolizable lysine you receive from a product can be a bit deceiving if you only look at cost per ton,” notes Mueller.

With the price of blood meal tracking around $1,400 per ton, looking at alternative lysine sources is definitely appealing, Mueller noted. At the current price of $1,400 per ton, the price per pound of metabolizable lysine from blood meal $10.62.

“Alternative lysine sources definitely have the edge right now,” notes Mueller.

For more information, contact Dr. Andy Mueller at (320) 260-0843 or email:

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