Growth performance and pork fat quality as measured by three methods of pigs fed 20% DDGS and slaughtered using a standard industry split marketing strategy

Abstract

A total of 40 pens containing 22 crossbred barrows (initial BW = 43.07 ± 1.61 kg; PIC 1050 × PIC 337 genetics) were housed in a commercial wean to finish facility. Pens were randomly allotted to dietary treatments in a 2 × 3 factorial arrangement with 2 levels of dried distillers grains with solubles (DDGS; 0% or 20%) and chosen for 1 of 3 marketing cuts removing 4, 8, and 10 animals from each pen. Fat tissue samples were removed from the anterior tip of the jowl and posterior to the sternum on the belly edge 1d postmortem. Fatty acid composition was determined via the Folch method, and iodine values (IV) were calculated from chemical titrations, fatty acid profile (GC IV), and in-plant Bruker near-infrared (NIR) spectroscopy. Pearson's correlation coefficients for IV determination methods were estimated. Inclusion of 20% DDGS did not change ( > 0.05) growth performance, whereas marketing cut affected performance, with the second cut producing the most efficient pigs ( < 0.01). Total SFA and MUFA concentrations were higher ( < 0.01) in belly and jowl fat from pigs fed 0% DDGS. Total PUFA and the PUFA:SFA in belly and jowl fat was higher ( < 0.01) when 20% DDGS was fed. Dried distillers grains with solubles inclusion increased IV in belly and jowl as determined by all 3 methods. Regardless of dietary treatment or fat depot, Pearson correlation coefficients between titration and GC IV, titration and NIR, and GC IV and NIR were 0.46 ( < 0.01), 0.68 ( < 0.01), and 0.43 ( < 0.01), respectively. These correlations suggest methods may rank samples equally but do not provide the same absolute IV. Belly fat had a lower IV ( < 0.01) than jowl fat using titration or GC IV methods, suggesting pigs have varied degrees of physiological maturity at specific fat depots when weight end points are used during the finishing phase. In conclusion, feeding 20% DDGS negatively affected fat quality but not growth performance, and marketing time changed growth performance.

Novel feed additives to improve lipid profiles in pigs

“…Belly fat. Not surprisingly, several studies have shown inclusion of DDGS in the diet increases belly IV (Whitney et al, 2006;Benz et al, 2010; regardless of IV determination method (Shircliff et al, 2015). Variations of added fat will change IV depending on the saturation of the source with CWG increasing IV compared to beef tallow, however, when fat was added at 6%, IV did not differ regardless of fat sources or fat depot (Kellner et al, 2014).…”

“…Regardless of inclusion level or depot, DDGS increases PUFA and raises IV of pork fat (Whitney et al, 2006;Xu et al, 2010;Shircliff et al, 2015). A cooperative study reported while SFA and MUFA levels decreased in subcutaneous fat, PUFA levels increased with increasing (15%, 30% and 45%) levels DDGS in the diet (Cromwell et al, 2011).…”

“…Jowl fat. Typically, jowl fat will have a higher IV compared to other fat depots and this is attributed to fat deposition patterns and differing physiological maturity of fat depots (Wiegand et al, 2011;Shircliff et al, 2015). Because correlations are weak between fat depots when pigs are slaughtered at the same weight, Wiegand et al (2011) suggest pigs slaughtered at the same weight may have different physiological maturities or be at different points on their respective growth curves.…”

“…Because correlations are weak between fat depots when pigs are slaughtered at the same weight, Wiegand et al (2011) suggest pigs slaughtered at the same weight may have different physiological maturities or be at different points on their respective growth curves. Not only are pigs different individually, but the fat depots within the same animal have different physiological maturities as well (Wiegand et al, 2011) with jowl fat being more mature compared to belly fat (Shircliff et al, 2015).…”

“…Research has also suggested majority of fatty acid turnover in porcine tissue will occur in the first 14 d of changing dietary fat source, concentration, or both (Irie and Sakimoto, 1992;Wiseman and Agunbiade, 1998). Typically, jowl fat will have a higher IV compared to other fat depots and this is attributed to fat deposition patterns and physiological maturity of fat depots (Wiegand et al, 2011;Shircliff et al, 2015). The jowl region is subject to a longer turnover rate of adipose tissue compared to belly and loin fat and is not easily impacted by changes in fat source or feeding duration (Stephenson et al, 2016).…”