Currently, dry milling ethanol plants produce primarily two co-products — wet corn distiller's grains (WCDG) and corn distiller's liquid solubles (CDLS) — frequently called “syrup.”

Typical production of these co-products is approximately 70% wet corn distiller's grains and 30% syrup.

When these two co-products are mixed together and dried, they produce the popular feed ingredient, corn distiller's dried grains with solubles (CDDGS).

Some ethanol plants have chosen to market some of the syrup separately as a feed ingredient to supplement ruminant or nonruminant diets.

Table 1 lists the typical dry matter analysis for WCDG and CDLS, or syrup. The highlighted values emphasize the amount of a specific ingredient in the WCDG and syrup. Basically, protein (amino acids) and fiber are much higher in the grains (WCDG), while fat and phosphorus are much higher in the solubles (syrup).

Can “Syrup” be Fed to Pigs?

Researchers at the University of Guelph conducted several successful feeding trials in which the syrup was incorporated in swine diets. No significant difference in growth performance was seen when compared to corn-based diets.

Similarly, pork producers with liquid- feeding systems are using the syrup in their feeding programs to significantly reduce feed costs.

Table 2 presents a grow-finish diet utilizing the syrup. Current ingredient prices were used (see Table 2 footnote).

The syrup analysis was converted to “air-dry” analysis for formulation, and the “as-is” liquid soluble price used was $16 and $32/ton.

Diet specifications were: lysine, 1% (digestible lysine, 0.83%); fat, 5.2%; total phosphorus, 0.53% (available phosphorus, 0.27%); and digestible threonine, 0.49%.

As the inclusion rate and the syrup cost increases, considerable savings can be realized if this ethanol by-product can be moved and fed in its liquid form. Basically, each 100 lb./ton (5%) of syrup replaces approximately 11 lb. of 46% soybean meal, 10 lb. of animal fat, 5 lb. of 21% monocalcium phosphate and 74 lb. of corn, with a few minor adjustments to other ingredients.

Cost of the syrup varies from “free” up to $30/ton at the plant. Naturally, shipping and handling costs must be considered, but as inorganic phosphorus prices continue to increase, syrup is a viable alternative feed ingredient if you have the feed facility to incorporate it into the diet.

Table 1. Typical Dry Matter Analysis of Wet Corn Distiller's Grains (WCDG) and Corn Distiller's Liquid Solubles (CDLS)
WCDG (%) CDLS (Syrup)(%)
Dry Matter 34.2 28.5
Protein 33.5 18.5
Lysine 1.04 0.68
Methionine 0.66 0.27
Threonine 1.27 0.71
Tryptophan 0.29 0.20
Fat 9.0 15.7
Fiber 9.5 2.5
Ash 3.1 8.4
Calcium 0.04 0.06
Phosphorus 0.54 1.28
Table 2. Grow-Finish Diet with Corn Distiller's Liquid Solubles (Syrup) Using Current Ingredient Prices*
Ingredient cost/ton
Diet “Air-Dry” Syrup (%) Syrup at $16/ton Syrup at $32/ton
1 0 $222.56 $222.56
2 $217.63 $218.88
3 5 $213.18 $215.68
4 102 $204.16 $209.16
5 22.41 $182.81 $194.02
*Corn, $4.76/bu.; 46% soybean meal, $320/ton; 21% monocalcium phosphate, $450/ton; animal fat, $0.25/lb.; lysine, $1.00/lb.
1Replaces all inorganic phosphorus and phytase
2Replaces all inorganic phosphorus