With high feed ingredient prices there is renewed interest in pelleting swine diets to capture feed efficiency improvements. Historic data in the literature suggests upwards of a 7 percent improvement in feed conversion and 5-6 percent improvement in daily gain when corn-soybean meal-based diets were pelleted.
The improvements in feed conversion were thought to be due to less wastage at the feeder and improved nutrient utilization due to such factors as starch gelatinization. However, we don’t feed corn-soybean meal based diets anymore. Today our diets are apt to contain various amounts of distillers grains and bakery by-products. In addition, feeder design improvements have lessened feed wastage at the feed trough overall and genetic/nutrition improvements have lowered feed conversions.
In a review of published pellet trials in the US from 1969 through 1999 Kansas State University swine nutritionists concluded that pelleting grow-finish diets improved daily gain 5.6 ercent and feed conversion 7.0 percent. However, when corn was less than $2 per bushel and soybean meal less than $200/ton, pelleting didn’t pay. The commercial charge for feed mill pelleting was often $7-8 per ton with ingredient prices totaling less than $100/ton there was no justification to pellet, especially if pelleting led to a higher incidence of stomach ulcers and pig deaths.