Effects of dried distillers grains with solubles on carcass fat quality of finishing pigs1

Abstract

A total of 1,112 pigs (initial BW of 49.8 kg) were used in a 78-d study to evaluate the effects of 0, 5, 10, 15, or 20% dried distillers grains with solubles (DDGS) and sex on carcass fat quality of finishing pigs. All diets contained 6% choice white grease and were fed in 4 finishing phases (50 to 59, 59 to 82, 82 to 105, and 105 to 123 kg, respectively). The experiment was conducted in a commercial research finishing barn in southwestern Minnesota. There were 9 replicates of each dietary treatment, with 25 to 28 pigs per pen, and barrows and gilts were distributed equally in each pen. On d 57, the 3 heaviest barrows from each pen were visually selected, removed, and marketed, and a total of 6 pigs per treatment were selected randomly for fatty acid analysis. On d 78, the remaining pigs from each pen were individually tattooed and shipped to a pork processing plant. Jowl fat, backfat, and belly fat samples were collected from 1 barrow and 1 gilt chosen randomly from each pen and analyzed for fatty acid composition. Iodine value (IV) was calculated for diets and fat samples. Fat quality data were analyzed as a split plot with DDGS treatment as the whole plot and sex as the subplot. Concentrations of C18:2n-6, PUFA, and IV increased (linear, P = 0.02) with increasing DDGS in backfat, jowl fat, and belly fat in pigs marketed on d 57 and 78. In contrast, C18:1 cis-9 and MUFA concentrations decreased linearly (P = 0.05) in all 3 fat depots with increasing DDGS. For every 10% DDGS included in the diet, IV of backfat, jowl fat, and belly fat increased by 2.3, 1.6, and 2.2 g/100 g, respectively. In pigs slaughtered on d 78, there were no (P ≥ 0.10) sex × dietary DDGS interactions observed. Compared with barrows, gilts had greater (P < 0.05) C18:2n-6, PUFA, and PUFA:SFA ratio and lesser (P < 0.03) C14:0 concentrations in backfat and belly fat but not jowl fat. Gilts had greater (P = 0.03) belly fat IV than barrows, but there were no (P > 0.25) differences between gilts and barrows in backfat and jowl fat IV. In summary, feeding increasing amounts of DDGS linearly increased the IV of backfat, jowl fat, and belly fat in pigs. Although jowl fat was less responsive to increased DDGS than backfat and belly fat, pigs fed diets with 20% DDGS and 6% choice white grease exceeded the maximum jowl IV of 73 g/100 g set by some packing plants.

Influence of dietary fat source and feeding duration on finishing pig growth performance, carcass composition, and fat quality1,2

“…Total MUFA was found to have an inverse relation ship to total PUFA concentrations in all 3 fat depots evaluated in this study, which would agree with Benz et al (2010). Feeding tallow maintained similar concentra tions of total MUFA in all fat depots whether they were fed the additional fat for the duration of the study or only a single period when compared with those fed the control diet.…”

“…Processors that are measuring IV target a value of 73 to 75 g/100 g, with high values being less ideal (Benz et al, 2010). High IV values create challenges for processors, as the "soft fat" can create problems in belly slicing and reduce shelf life due to oxidative rancidity (NRC, 2012).…”

Effects of conjugated linoleic acid or betaine on the growth performance and fatty acid composition in backfat and belly fat of finishing pigs fed dried distillers grains with solubles

“…The changes in the fat IVs in pigs fed diets containing DDGS are most likely a result of the relatively large quantities of unsaturated fatty acids, particularly C18:2 in corn because the increases in dietary unsaturated fatty acid concentrations will increase the carcass fat IV. In the current study, the IV of the backfat and belly fat increased in pigs fed diets containing 300 g DDGS/kg, which agrees with previous reports (Benz et al, 2010;Dahlen et al, 2011), indicating that the IV of fat increased with increased DDGS content in grower-finisher pig diets. Regression analysis in the research has hundreds of pigs indicated that IVs increased 4.3 units for every 10 percentage unit inclusion of DDGS in the diet (Cromwell et al, 2011).…”

“…In the present study, the pigs fed the diets containing DDGS increased the percentage of C18:2 and PUFA, but the C16:0 and SFA decreased in both the backfat and belly fat. Similarly, Dahlen et al (2011), Benz et al (2010 and Xu et al (2010) observed changes in the fatty acid profiles of pigs fed increased dietary DDGS, Total PUFA = ((C18:2) + (C18:3) + (C18:3) + (C20:2) + (C20:4)). Means within a row with different superscripts differ (P < 0.05).…”

Validation of metabolisable energy prediction equation for de-oiled corn distillers dried grains with solubles fed to finishing pigs

“…other papers (Benz et al 2010;Rickard et al 2012) which reported an increase in IV as the concentration of DDGS increased. However, in this experiment, the fat concentrations between each group were similar and the lipid in diets was mainly supplied by corn oil and soybean oil.…”