Two ruminally cannulated cows fed a ration of 30 percent concentrate and 70 percent roughage were used to determine the in situ ruminal digestibility and intestinal digestibility of raw soybeans and soybeans extruded at three different temperatures (145, 155 & 165° C).  The degradation of dry matter and crude protein was determined using nylon bags suspended in the rumen for different lengths of time.  Effect ruminal degradabilities were calculated assuming an outflow from the rumen of 0.06/hour.  Soybean extrusion at all temperatures decreased the effective protein degradability (P>0.05).  Extrusion at the highest temperature significantly decreased effective protein degradabilities (44%); where as the values for the other two processing temperatures were similar (50.8 and 50.3%).  The intestinal digestibilities were estimated at 87.2, 89.7, 92.0 and 92.6% for the raw soybeans and soybeans extruded at 145, 155 & 165° C., respectively.  These results provide insight into temperatures needed for rumen by-pass and the high digestibility of soy protein in the intestine of dairy cows.

Nowak, W., S. Michalak and S. Wylegala.  2005.  In situ evaluation of ruminal degradability and intestinal digestibility of extruded soybeans.  Czech J. Animal Sci. 50(6): 281-287.

DDGS for Pigs
A growth performance and carcass evaluation study was conducted to determine the maximal inclusion rate of corn distillers grains with solubles (DDGS) that could be used in grower-finisher pig diets when formulated on a total amino acid basis.  Two hundred and forty pigs were allotted to twenty-four pens and then to four diet treatments (0, 10, 20 & 30% DDGS).  All diets were formulated to contain similar levels of total lysine, metabolizable energy, calcium and phosphorus.  The pigs were slaughtered and carcass data collected when the pigs reach 114 kg.  The pigs fed the 20 and 30% DDGS diets had reduced average daily gains (>0.05) compared to the pigs on the 0 and 10% DDGS diets.  Average daily feed intake was unaffected by treatment and pigs fed 30% DDGS had lower feed efficiency (P>0.05).  Dietary treatment did not seem to have any major effect on carcass quality.  The authors conclude that the results of this study indicate that diets for growing-finishing pigs fed 10% DDGS had no detrimental effects on pig performance, carcass quality, or pork quality.  When diets are formulated on a total amino acid basis, inclusion of 20% or more resulted in decreased growth performance and the 30% inclusion level will probably affect carcass-processing traits.  NOTE: The key is to make sure the amino acids are sufficient to meet the pig’s daily requirements for optimum performance.  A high quality soybean meal is needed to balance the amino acid levels in the diets high in corn products.  In these growing-finishing diets, about seven plus pounds of corn, two pounds of soybean meal and a half-pound of soybean oil were replaced by including ten pounds of DDGS in the ration formulation.

Whitney, M.H. and co-workers.  2006.  Growth performance and carcass characteristics of grower-finisher pigs fed high-quality corn distillers dried grains with solubles originating from a modern Midwest ethanol plant.  J. Animal Sci. 84: 3356-3363.

In the November issue of Pork Magazine, a leading nutritionist from the University of Minnesota discussed the use of distillers dried grain with solubles (DDGS) in swine rations.  He indicates that up to ten percent DDGS can be included in swine diets with excellent results, if the diets are formulated on a total-lysine basis.  If higher inclusion rates are used, the diets should be formulated on a digestible-amino acid basis to achieve satisfactory performance.  The article provides maximum DDGS levels that could be included in swine diets for nursery pigs (25%), growing/finishing pigs (20%), gestating sows (50%), and lactating sows (30%).  Again, assuming all amino acids are met for optimum performance.

The article also included several factors that are preventing widespread use of DDGS.  These include:

• Variability in DDGS nutrient content and digestibility;
• Low particle size and flowability problems with some DDGS sources;
• Ability to pellet DDGS diets;
• Managing the effects of increased corn oil in DDGS on pork-fat quality;
• Possible palatability issues and feed intake at high DDGS inclusion rates;
• Fast, accurate and cheap methods to estimate amino acid digestibilities of DDGS sources; and
• Need for accurate net energy values for DDGS sources.

Jerry Shurson.  2006.  Ethanol production is here to stay...so let’s figure out how to use the byproducts. Pork Magazine, November issue, page 8-9.