Effects of dried distillers grains with solubles and extruded expelled soybean meal on growth performance and carcass characteristics of grow-finish pigs

A total of 120 barrows (maternal line PIC 1050) with an initial BW of 105.7 lb were used in an 83-d trial to study the effects of dried distillers grains with solubles (DDGS) and extruded expelled soybean meal (EESM) on growth performance and fat quality. Pigs were blocked by weight and randomly allotted to one of six treatments with two pigs per pen and 10 pens per treatment. Diets were: a corn-soybean meal control diet with no added fat, corn-EESM diet with no added fat, corn-EESM diet with 15% DDGS, cornsoybean meal diet with 15% DDGS, and 1.55% choice white grease (CWG), corn-soybean meal diet with 3.25% CWG, and corn-soybean meal diet with 4.7% CWG. Diets were formulated to have three dietary iodine value (IV) levels (42, 55, and 62) to compare the impact of fat source within dietary IV levels. On d 83, jowl and backfat samples were collected. Pigs fed the control diet, EESM, or 4.7% CWG had increased ADG compared with pigs fed the diet containing EESM with 15% DDGS. Pigs fed the control diet had increased ADFI compared with all other treatment. Pigs fed EESM with 15% DDGS and the diets with 4.7% CWG had improved F/G compared with pigs fed the control and pigs fed DDGS with CWG. Pigs fed high CWG had greater (P<0.05) loin depth compared with pigs fed low CWG. Pigs fed either of the diets with 15% DDGS had increased backfat IV compared with pigs fed diets without DDGS. Pigs fed EESM had increased backfat IV when compared with the control diet or diets with 3.25 or 4.7% CWG. Adding DDGS to the diet or using EESM increased IV of jowl fat. Adding CWG to the control diet also increased IV of jowl fat. Feeding ingredients with higher levels of unsaturated fat, such as EESM and DDGS, had a greater impact on fat IV than CWG even when diets were formulated to similar IV levels.; Swine Day, 2007, Kansas State University, Manhattan, KS, 2007


Summary
A total of 120 barrows (maternal line PIC 1050) with an initial BW of 105.7 lb were used in an 83-d trial to study the effects of dried distillers grains with solubles (DDGS) and extruded expelled soybean meal (EESM) on growth performance and fat quality.Pigs were blocked by weight and randomly allotted to one of six treatments with two pigs per pen and 10 pens per treatment.Diets were: a cornsoybean meal control diet with no added fat, corn-EESM diet with no added fat, corn-EESM diet with 15% DDGS, corn-soybean meal diet with 15% DDGS, and 1.55% choice white grease (CWG), corn-soybean meal diet with 3.25% CWG, and corn-soybean meal diet with 4.7% CWG.Diets were formulated to have three dietary iodine value (IV) levels (42, 55, and 62) to compare the impact of fat source within dietary IV levels.On d 83, jowl and backfat samples were collected.Pigs fed the control diet, EESM, or 4.7% CWG had increased ADG compared with pigs fed the diet containing EESM with 15% DDGS.Pigs fed the control diet had increased ADFI compared with all other treatment.Pigs fed EESM with 15% DDGS and the diets with 4.7% CWG had improved F/G compared with pigs fed the control and pigs fed DDGS with CWG.Pigs fed high CWG had greater (P<0.05)loin depth compared with pigs fed low CWG.Pigs fed either of the diets with 15% DDGS had increased backfat IV compared with pigs fed diets without DDGS.Pigs fed EESM had increased backfat IV when compared with the control diet or diets with 3.25 or 4.7% CWG.Adding DDGS to the diet or using EESM increased IV of jowl fat.Adding CWG to the control diet also increased IV of jowl fat.Feeding ingredients with higher levels of unsaturated fat, such as EESM and DDGS, had a greater impact on fat IV than CWG even when diets were formulated to similar IV levels.

Introduction
Dried distillers grains with solubles (DDGS) and extruded expelled soybean meal (EESM) can be economical to feed to growing and finishing hogs.However, the inclusion of these ingredients increases the dietary fat level when they are substituted for corn or soybean meal.Carcass composition is altered when fat level increases in the diet, causing softer carcass fat.This may have implications from a processor acceptance standpoint.Iodine value is a measure of the level of unsaturation of fats, and therefore a measure of fat firmness.Carcass iodine value must be further researched to know the full carcass quality implications from feeding different fat sources for various time periods.Therefore, the purpose of this trial was to evaluate the effects of dried distillers grains (DDGS) and extruded expelled soybean meal (EESM) growth performance and carcass characteristics of growfinish pigs.

Procedures
One hundred twenty crossbred barrows, (PIC 1050) with an initial weight of 105.7 lb were used in an 83-d experiment.Pigs were blocked by weight and allotted to one of six treatments with 10 replicate pens per treatment.Pigs were housed with two pigs per pen in an environmentally controlled finishing barn with 4 ft × 4 ft pens with totally slatted floors.Each pen was equipped with a onehole dry self-feeder and nipple waterer to allow ad libitum access to feed and water.
Diets were: a corn-soybean meal control diet with no added fat (calculated IV of 42), corn-EESM diet with no added fat (calculated IV of 54), corn-EESM diet with 15% DDGS (calculated IV of 62), corn-soybean meal diet with 15% DDGS, and choice white grease (CWG, calculated IV of 54); corn-soybean meal diet with low CWG (calculated IV of 54), and corn-soybean meal diet with high CWG (calculated IV of 62).Diets were formulated to have three dietary IV levels to compare the impact of fat source within dietary IV levels.The analyzed dietary IV was lower than the calculated values.However, two treatments had very similar weighted IV (DDGS with CWG and high CWG (Table 6).Prior to being placed on test, pigs were fed a corn-soybean meal-based diet.
Diets were formulated to be fed in three phases from d 0 to 26, 26 to 55, and 55 to 83 to correspond with approximate weight ranges of 90 to 150, 150 to 210, and 210 to 270 lb (Tables 1, 2, and 3).A constant TID lysine: ME ratio was maintained by altering the corn and soybean meal level in the basal diet when adding the fat sources.
Pigs and feeders were weighed on d 12, 26, 41, 55, 69, and 83 to calculate ADG, ADFI, and F/G.Pen served as experimental unit for all statistical analysis.
The fatty acids are represented as a percentage of the total fatty acids in the sample.
Data were analyzed in a randomized complete-block design with pen as the experimental unit.Analysis of variance was performed by using the MIXED procedure of SAS.Contrasts were used to determine the effects of the dietary treatments.Hot carcass weight was used as a covariate for last rib backfat, 10 th rib backfat, loin depth, and percentage lean.

Results and Discussion
From d 0 to 83, pigs fed the control diet, EESM or high CWG had greater (P<0.05)ADG compared with pigs fed EESM with 15% DDGS ( Most treatments had jowl fat iodine values approximately 5 g/100g h greater than backfat iodine values.However, both diets containing DDGS had jowl fat and backfat iodine values that were more similar.This can be explained by evaluating the effect each individual fatty acid had on iodine value (Table 6).Pigs fed the control diet had an increase of 4 g/100g from backfat to jowl fat due to C 18:1 fatty acids (effect of backfat C 18:1 = 36.05,effect of jowl fat C 18:1 = 40.05).This trend is similar for all treatments and explains why jowl fat iodine value is higher than backfat iodine value.The effect C 18:2 fatty acids had on iodine value is similar for jowl fat and backfat in most treatments.However, pigs fed either diet containing DDGS had less C 18:2 fatty acids in jowl fat than backfat.This difference was similar to the effect C 18:1fatty acids had, and essentially cancelled it out.
These results confirm that adding fat to finishing pig diets improves growth performance.Feeding DDGS in this trial resulted in a decrease in ADG and ADFI.Adding DDGS, EESM, or CWG increased IV and C 18:2, and reduced C saturated fatty acids.Finally, feeding ingredients with higher levels of unsaturated fat, such as EESM and DDGS, had a greater impact on fat iodine value than CWG even when dietary iodine values were similar.Also, feeding pigs a diet with more unsaturated fat may lead to jowl fat and backfat to have more similar iodine values.

Table 1 . Phase 1 Diet Composition (as-fed basis) a
values for diet formulation were derived from NRC, 1998.
b DDGS nutrient

Table 5 . Effects of DDGS and EESM on Carcass Performance a
bcdefTreatments with different superscripts differ, P<0.05.