WASHINGTON — Wet distiller's grain with solubles (W.D.G.S.) could serve as an inexpensive alternative to traditional feed ingredients when fed to livestock, Agricultural Research Service (A.R.S.) studies reveal.
A.R.S. writer Sharon Durham explains W.D.G.S. is a common ethanol byproduct that could replace more costly traditional feed ingredients, such as corn, soybean meal, urea and mineral supplements. When used as livestock feed, W.D.G.S. typically costs approximately10% less than corn.
The effects of feeding W.D.G.S. to cattle have been studied by A.R.S. scientists at the U.S. Meat Animal Research Center (U.S.M.A.R.C.) in Clay Center, Neb. Feedlot performance, energy utilization efficiency, post-harvest meat characteristics and cattle manure emissions were investigated.
In one study, growth rate, feed intake and feed efficiency for cattle in the "finishing phase" — the approximately 120 to 140 days leading up to slaughter — were monitored. In steers, fed diets of 20% to 40% W.D.G.S., performance in those areas was equal to or better than that of a group of cattle that did not receive the W.D.G.S.
Feed efficiency was examined by another study; specifically, the amount of heat animals produced while digesting their food was studied. Researchers found no significant difference in heat production between cattle fed 0%, 20%, 40% or 60% W.D.G.S. However, they did observe lower energy utilization efficiency at the highest rate, a factor that could reduce feedlot performance.
Regarding meat quality, researchers found feeding a diet of 20% or 40% W.D.G.S. produced carcasses that were the same or better for yield and quality traits than carcasses of cattle that did not eat the W.D.G.S., Ms. Durham wrote. Cattle fed 60% W.D.G.S. diets were lighter, leaner, less marbled and had lower yield grades than cattle in the groups that consumed lower quantities of W.D.G.S. or none at all.
One microbiologist confirmed that as the concentration of W.D.G.S. increased in the diet, greater concentrations of nitrogen, phosphorus and sulfur appeared in manure, mostly due to excess crude protein. Researchers also examined how W.D.G.S. diets affected persistence of E. coli bacteria in cattle feces and manure.