According to research within our lab and reports of others, the fat source in the diet is a significant driver of pork fat profile and ultimately fat quality in the final product. We expect the timing of marketing pigs to interact with dietary fat source and this relationship could alter feeding strategies of certain fat sources to optimize fat quality in pork. Therefore, in the following study, we sought to determine the fatty acid profile and iodine value of jowl and belly fat from hogs fed a diet including 20% DDGS and marketed in three cuts from a commercial facility. Iodine value was determined using three methods; chemical titrations, calculated from a fatty acid profile and using in-plant near infrared (NIR) spectroscopy. Specifically, we want to understand how traditional marketing cuts from finishing facilities affect early maturing pigs in relation to their fat profiles and how these pigs differ from their later marketed contemporaries.
Eight hundred and eighty crossbred growing finishing hogs (PIC genetics) were raised in a commercial facility with 22 pigs allotted to each pen. Twenty pens were fed a control corn and soy based diet and the remaining 20 pens were fed a diet containing 20% DDGS (Tables 1 and 2). Animal growth and performance was measured by pen body weight, average daily gain, average daily feed intake and gain to feed ratio. The heaviest hogs were marketed first removing 4, 8 and 12 head per pen in the first, second and third marketing cuts, respectively. Belly and jowl fat samples were collected 1 day postmortem from chilled carcasses in a commercial slaughter facility. Lab analysis was performed at the University of Missouri Meat Science Laboratory.
Growth performance was unaffected by the inclusion of DDGS in the diets of growing and finishing hogs. However, marketing cut changed growth parameters, specifically ADG. The hogs marketed in the second cut have a clear advantage over counterparts in the first and third cuts. By removing the fast growing, early maturing hogs in the first cut, feeder and floor space expanded, allowing the remaining hogs to more closely meet their genetic potential. The genetically superior animals grew faster and gained more thereby surpassing the slow growing, late maturing hogs left in the third cut.