January 24, 2011

 

US study focuses on glycerin in swine diets

 

US researchers from the University of Illinois (U of I) are expanding their assessment of the glycerin use in swine diets after an increasing need to discover alternatives of cost-effective livestock feed.

 

This study, led by U of I graduate research assistant Omarh Mendoza, was published in the Journal of Animal Science and reports that swine diets may include up to 15% glycerin and achieve similar performance to a conventional corn/soybean diet. 

 

"Glycerin is not a new product, but little is known about its role as a feed ingredient for swine," said Michael Ellis, U of I professor in the Department of Animal Sciences. "Previous studies have shown variable results," he added.

 

Glycerin is a major co-product of biodiesel production. This resulting liquid energy source is sweet and palatable, Ellis said. While it's more commonly used by humans, it has the potential for greater inclusion in livestock diets.

 

"We performed a standard feedstuff digestibility evaluation," Ellis said. "We determined its energy digestibility and metabolising energy value. We used this value to formulate diets in a controlled study here at the U of I Swine Research Centre."

 

The study determined that glycerin could be fed up to levels of 15% of the swine diet.

 

"We didn't test it at higher levels because the efficiency of use of the energy may decrease so we don't recommend using glycerin at levels higher than 15%," he said.

 

Previous studies suggested that feeding glycerin could improve meat quality, Ellis added. However, the U of I study revealed no effect of feeding glycerin on meat quality. The glycerin diet had comparable results to the corn/soy diet.

 

Although glycerin looks to be a promising alternative, as with any feedstuff, it depends upon current market prices.

 

"Glycerin has alternative uses beyond being used as a feed ingredient," Ellis said. "It is available, but the demand for this ingredient sometimes causes it to be too expensive to use in a diet. But there are occasions when it's economically feasible to use. If the biofuels industry keeps growing, that could make it even more accessible in the future."

 

Aaron Gaines, co-researcher and Vice President of Production Resources & Operations at The Maschhoffs, said feed-flow issues need to be considered when using glycerin.

 

"Glycerin is available to the swine industry as crude glycerin," Gaines said. "Crude glycerin is a viscous liquid, and dietary inclusion rates of 5% or greater can result in feed-flowing ability issues."