LEXINGTON, Ky. — Four quadrillion calories may be lost each year because of the inefficient digestion of feed grains by livestock.

That sounds like an incomprehensible number, but 25 percent of nutrients in grains like corn, wheat, barley, sorghum, soybean, rapeseed, cottonseed and other grains are trapped by fibre that animals cannot digest, said Alltech scientist Kyle McKinney at the company’s international conference held recently in Lexington.

“If we look at all the grains produced in the year, it is about three billion tonnes of grain. If we look at the calorie loss of the grains because of inefficiency, four quadrillion calories are lost,” he said in an interview.

Enzymes must be added to feed mixes to aid that digestive process. An enzyme attaches to the fibre substrate and degrades it to release calories and nutrients for the animal.

Using nutrients more efficiently is one way to avoid waste, which limits the amount of land needed for agricultural purposes.

McKinney works mostly with monogastric animals such as swine and poultry but some feed trials showed enzymes added to cattle diets can improve weight gain and efficiency.

Enzymes have been used for about 25 years to release nutrients but in the last five years more research has focused on the loss of calories.

About 100 grams of enzymes mixed into a tonne of feed seem sufficient to release nutrients and build performance of the animal and improve gut health and weight gain.

McKinney suggested producers talk with their nutritionists to learn what enzymes are being fed and what is being targeted in the diet.

There are dozens of fibre substrates so more varieties of enzymes may be needed.

“If I can add a complex of enzymes, it allows me to change the nutrients I am adding to a diet, which means I save money,” he said.