Kansas State University (KSU) researchers are investigating ways to improve the economics of feeding DDGS from the nursery through grow-finish phases
ver the course of three different research trials, more than 2,000 pigs were fed dried distiller's grains with solubles (DDGS) diets, which varied in a host of different ways.
DDGS + Enzymes in Nursery Diets
Researchers determined that adding commercial enzymes to typical corn-soybean meal-based diets had no effect on nursery pigs' average daily gain (ADG), average daily feed intake (ADFI) or feed/gain (F/G) ratio. Likewise, adding enzymes to diets with 15% or 30% corn or sorghum DDGS had no effect on these performance variables.
The KSU team says the research indicates the use of high levels of DDGS, up to 30%, in nursery pig diets, can be a viable option to reduce diet costs in light of increasing corn prices. However, the higher DDGS levels may reduce growth rates, they add.
In another trial, 1,032 pigs were followed through a 90-day grow-finish experiment to determine the effects of high levels of DDGS and enzyme supplementation on growth performance and carcass characteristics.
Researchers concluded that up to 60% DDGS for grow-finish pigs provides a good option to replace corn in the diet, inhibiting growth slightly, and the inclusion of enzymes had no significant impact on growth or feed efficiency.
If finishing spaces are available to accommodate pigs for several more days and the potential feed cost savings are greater than the extra space costs, using high levels of DDGS in growing-finishing diets is highly feasible.
This study indicates that up to 60% DDGS may be added to diets without adversely affecting growth or carcass yield, as long as DDGS levels are reduced to 20% for at least 12 days before slaughter. High DDGS levels will increase belly fat iodine values, which may affect carcass value.
Europeans use enzymes to improve feed utilization and decrease the cost of gain when pigs are fed high-fiber diets.
Corn is highly digestible and has low fiber, so the addition of enzymes in corn-based diets has not shown an economic improvement in growth performance. However, because the starch fraction is removed, DDGS have a higher fiber fraction than corn, causing researchers to speculate that enzymes may be beneficial in U.S. diets containing DDGS.
KSU researchers evaluated the effects of different commercial enzymes in diets containing DDGS. Three of those trials are summarized below:
Nursery Trial — Experiment #1
The first nursery trial focused on the effects commercial enzymes could have in DDGS-based nursery diets. Two experiments were conducted.
The first utilized 180 pigs in a 27-day trial comparing weanling pig performance when three commercial enzyme products — Easyzyme, Hemicell-W and Porzyme — were added to diets containing 30% DDGS.
Pigs averaging 19.9 lb. were divided into six pens/treatment with six pigs/pen. Ad libitum access to feed and water was provided by one nipple waterer and one feeder/pen.
Enzyme inclusion levels were based on manufacturers' recommendations and guaranteed analysis. The five dietary treatments, fed in meal form, included:
Positive control, corn-soybean meal-based diet;
Control diet with 30% corn DDGS;
Nursery Trial — Experiment 2
30% DDGS diet with 0.05% Easyzyme;
30% DDGS diet with 0.05% Hemicell-W; and
30% DDGS diet with 0.05% Porzyme.
ADG, ADFI and F/G were determined by weighing pigs and measuring feed disappearance on Days 7, 14 and 27 of the trial. See Table 1 for diet analysis.
Overall, pigs fed the corn-soybean meal diet or the corn-soybean meal diet with 30% DDGS, with or without Porzyme, performed similarly for ADG, ADFI and F/G (Table 2). However, pigs fed diets containing Hemicell-W and Easyzyme had poorer ADG than pigs fed the positive control diet. Pigs fed the diet containing Hemicell-W also had lower ADG than pigs fed the control diet or the diet containing Porzyme. There were no differences in ADFI or F/G.
Continue on Page 2: Nursery Trial - Experiment 2
Nursery Trial — Experiment 2
The second experiment in the nursery trial looked at the performance of 350 nursery pigs fed the commercial enzyme, Easyzyme, in diets containing various levels of both corn- and sorghum-based DDGS from different ethanol plants. The pigs, averaging 24.3 lb. at the beginning of the trial, were placed five/pen with seven pens/treatment.
Each pen contained a four-hole, dry self-feeder and one cup waterer, providing ad libitum access to feed and water. Pigs were weighed and feed disappearance was measured on Days 7, 14 and 21 of the trial. The 10 dietary treatments, fed in meal form, included:
Positive control, corn-soybean meal-based diet;
Control, corn-soybean meal-based with 15% corn DDGS;
Control, corn-soybean meal-based with 30% corn DDGS;
Control, corn-soybean meal-based with 30% corn DDGS + 0.05% Easyzyme;
Control, corn-soybean meal-based with 15% sorghum DDGS from Source 1 (Kansas Ethanol, Lyons, KS);
Control, corn-soybean meal-based with 30% sorghum DDGS from Source 1;
Control, corn-soybean meal-based with 30% sorghum DDGS from Source 1 + 0.05% Easyzyme;
Control, corn-soybean meal-based with 15% sorghum DDGS from Source 2 (U.S. Energy Partners, Russell, KS);
Control, corn-soybean meal-based with 30% sorghum DDGS from Source 2; and
Control, corn-soybean meal-based with 30% sorghum DDGS from Source 2 plus 0.05% Easyzyme.
The corn DDGS had lower crude protein and fiber content, but higher crude fat content than sorghum DDGS. Sorghum DDGS from Source 1 had higher crude protein, fat, fiber and ash content than sorghum DDGS from Source 2. Dietary analysis for Experiment 2 is listed in Table 3.
Overall, there were no interactions between enzymes and DDGS source for any of the growth variables (Table 4). Pigs fed diets with higher levels of corn DDGS grew nearly as well and as efficiently as those fed the control diet.
Pigs fed diets with increasing sorghum DDGS had poorer F/G than pigs fed the control diet, but daily gains were similar. Pigs fed diets containing sorghum DDGS had poorer F/G than pigs fed diets containing corn DDGS.
The source of sorghum DDGS had minimal effects on growth traits. However, pigs fed diets containing 30% DDGS had ADG, ADFI and F/G similar to those fed diets with 30% DDGS plus 0.05% enzyme. The poorer feed efficiency of pigs fed the sorghum DDGS diets may be a result of their lower energy content.
Growing Pig Trial
KSU researchers also conducted a 56-day study in which Agri-King's REAP enzyme product's energy replacement value was studied.
Pigs were assigned to one of six dietary treatments, fed in three phases. The dietary treatments had increasing levels of fat from 0, 2.5 and 5%, with or without added enzyme at 0.05% or 0% of the Agri-King REAP enzyme product.
The Phase 1 diet was fed from approximately 75 to 110 lb., Phase 2 from 110 to 160 lb., and Phase 3 from 160 to 200 lb. The diets were based on corn and soybean meal with 15% added DDGS and balanced to a constant lysine-to-calorie ratio at 2.98, 2.68, and 2.38 g/Mcal ME (metabolizable energy) for Phases 1, 2 and 3, respectively.
At the conclusion of the 56-day study, the researchers found the addition of the commercial enzyme did not affect growth performance, but ADG and F/G improved with the addition of fat in the corn-soybean meal-based diets with 15% DDGS (Table 5 and Table 6).
Continue on Page 3: Grow-Finish and Carcass Study
Grow-Finish and Carcass Study
KSU researchers conducted a 90-day grow-finish trial using 1,032 pigs with an initial weight of 101.5 lb. The goal was to determine the effects of high levels of DDGS and enzyme supplementation on growth performance and carcass characteristics of grow-finish pigs.
Pigs were randomly allotted to one of seven dietary treatments (Table 7), with six pens/treatment. The trial was conducted in a commercial research finishing barn with 18 × 10 ft., totally slotted pens with deep pit manure storage. Each pen contained one self-feeder and one cup waterer. The barn was equipped with a robotic feeding system capable of providing and measuring feed amounts on an individual pen basis.
The control diet contained 30% DDGS. The remaining treatments were arranged based on a DDGS level of 45 or 60%, and enzyme inclusion consisting of none, Product A or Product B.
Product A was a commercial enzyme blend containing protease, amylase, xylanase, Beta-glucanase, pectinase, cellulose and phytase. Product B was an experimental proprietary blend of enzymes selected to have maximum activity for the non-starch polysaccharides (NSP) in DDGS.
Diets were fed in four phases. During the first two weeks (Phase 1), the 60% DDGS treatments contained only 45% DDGS and were fed from approximately 100 to 128 lb. Phase 2 was fed from 128 to 185 lb., Phase 3 from 185 to 230 lb., and Phase 4 from 230 to 270 lb.
Pigs allotted to the 60% DDGS treatment were fed 45% DDGS during the first two weeks of the experiment. DDGS levels for all treatments were decreased to 20% from Day 78 until the end of the trial.
Overall, enzyme supplementation did not affect ADG, ADFI or F/G. Regardless of enzyme treatment, ADG decreased as DDGS increased due to the reduction in ADFI. After topping out the pen and adding Paylean to the diets at Day 78, ADFI tended to increase in pigs previously fed 45 and 60% DDGS. The decrease in ADFI during the first 78 days of the trial lowered overall ADFI with increasing DDGS levels, but did not affect overall ADG, F/G or final weight. Results are illustrated in Table 7, Table 8, and Table 9.
Belly fat samples were collected from 18 randomly selected pigs (six pigs/treatment), from the three non-enzyme-supplemented DDGS treatments to determine fat iodine value. There were no differences in carcass weight, carcass yield, backfat, loin eye depth, percent lean and fat free lean index after adjusting to a common carcass weight.
Because DDGS contains high amounts of corn oil, which contains a higher percentage of unsaturated fatty acids, DDGS-fed pigs tend to have softer fat in their carcasses as measured by increased iodine value. This research showed increasing dietary DDGS increased iodine value of belly fat.
The absence of enzyme effect on pig performance in this study was similar to the results of other KSU research with DDGS-containing diets. The researchers say it is possible that the products used in this study may not have the optimal balance of enzyme activities specific for the substrates present in the DDGS used in the experimental diets.
Other factors that can affect the efficacy of the enzyme products include the amount of enzyme used, age of the animal, overall nutrient density of the diet, and particle size.
Researchers: Cassie K. Jones, Jay Jacela, Jon Bergstrom, Mike Tokach, Joel DeRouchey, Jim Nelssen, Steve Dritz and Robert Goodband, Kansas State University; K.J. Prusa, Iowa State University; and P. Brown, Agri-King, Inc. Contact Jacela or Jones at (785) 532-1270.