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% improvement in feed conversion and 5-6% 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% and feed conversion 7.0%. 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.
Today we have diets that contain 20-40% DDGS and total ingredient costs well above $300/ton. Suddenly everyone is talking about pellets and pellet quality. With less starch in the diet, does pelleting return a 7% improvement in conversion? What about health issues such as ulcers, etc?
At the Midwest American Society of Animal Science meeting a few weeks ago there were several papers on the topic. Nutritionists with Hubbard Feeds reported a 5.6% improvement in feed conversion for the late nursery period with diets containing 20% DDGS when the pellets were screened (i.e. good quality pellets with minimal fines). As the amount of fines in the diet increased, the improvements in feed conversion lessened. This highlights the challenge for many considering pellets. A good quality pellet slows down mill through-put.
How many fines can you accept in a pelleted diet and still see an sufficient improvement in feed conversion (and maybe daily gain) to pay the cost of the pellet process? The answers aren’t clear for all the combinations of diet ingredients, eating behaviors associated with different genetic lines and ingredient pricing. However I know many of the private research sites in the US are examining this question very diligently as they try and capture small but significant cost of production advantages in a period of low margins.
I’ve also talked with many toll mill managers who are trying to decide if their mills should upgrade to pellet capabilities in order to maintain a strong customer base.