A total of 1,036 barrows and gilts were assigned to one of 4 dietary treatments across a 115-day experiment period: a positive control diet using a DDGS source with low levels of DON (~0.8 ppm), a negative control diet using a DDGS source with high levels of DON (~18.6 ppm), and two additional diets containing either Defusion (Akey, Inc., Lewisburg, OH) or Integral (Alltech, Nicholasville, KY) added to the negative control diet. The experiment was conducted in a commercial research barn owned by Iowa Select Farms; research management of the farm was provided by Akey. Pigs were weighed individually at the beginning and end of the experiment and as pen groups in the intermediate periods. Feed was provided as a mash and both feed and water were offered ad libitum. Diets were based on corn and soybean meal, with 20% (phase 1 and 2) or 25% (phase 3 through 6) corn DDGS. Because pigs did not appear to be seriously affected by the DON in phases 1 and 2, the level of DDGS was elevated in all diets to 25%, thereby increasing the level of DON in the negative control diet. Contaminated DDGS ran out prior to the end of the 6th phase, so the experiment was terminated at that time. Thus, carcass information was not recorded, as the pigs had not yet reached market weight.
DON contamination reduced final body weight, ADG, ADFI and feed conversion (P < 0.05). Defusion improved all performance outcomes and resulted in final BW, ADG, ADFI and feed conversion that were not statistically different from the positive control-fed pigs (P > 0.05). The benefit of Defusion was greater in barrows than in gilts. Indeed, gilts failed to respond to Defusion to the same extent as barrows. Defusion also reduced the standard deviation of final BW (P < 0.05), although the magnitude of improvement was small. Integral improved ADG (P < 0.05), but not final BW, ADFI or feed conversion, compared to the negative control-fed pigs (P > 0.05). Integral achieved numerical improvements in final BW and ADFI, but the differences were not statistically significant. The adverse impact of DON-contamination of DDGS on pig performance was clearly demonstrated. The use of mycotoxin binders offers some encouragement to pork producers faced with mycotoxin problems, but there appear to be differences in their effectiveness among products.
An economic analysis of the experiment results was undertaken. Within 4 market ($40, $60, $80 and $100/cwt) and 3 feed ($50, $70 and $90 feed cost/pig) scenarios, the presence of mycotoxins reduced the return over feed by up to $20.68 per pig; even the lowest impact reduced returns by $2.06 per pig. Defusion affected return over feed cost, after including the cost of the product, ranging from a net cost of $0.15 per pig to a net gain of $13.25 per pig. The magnitude of the impact was a factor of market hog prices and feed cost. Integral changed return over feed cost, after including the cost of the product, ranging from a net cost of $1.37 per pig to a net gain of $5.23 per pig. Because neither improvements in market weight nor feed conversion were statistically significant with Integral, the financial benefit must be viewed with great caution. If the numerical increase in body weight and in feed conversion may be due to chance, then so too could be the financial returns.
While mycotoxins were not a problem in the 2010 crop, the results of this experiment will allow pork producers to be much better prepared to deal with DON contaminated feed when it returns the next time.