Utilization of Enzymatically Digested Food Waste in Growing-Finishing Pigs. 2. Meat Quality and Fatty Acid Profiles

Our previous research revealed that enzymatically digested food waste (fruit, vegetable, meat, and dairy products) contains over 20% fat as DM basis. Although the high fat contents in this product will benefit growing pigs and early finishing pigs, it may not benefit late finishing pigs. Therefore, the objective of this experiment was to evaluate meat quality and fatty acid profile of growing and finishing pigs fed with an enzymatically digested food waste. Fifty-six crossbred pigs (approximately 32.99 kg BW) were randomly assigned to one of 2 dietary treatments with 7 replicate pens and 4 pigs per pen. A 3-phase feeding program was used with d 0 to 28 as Phase 1, d 28 to 53 as Phase 2, and d 53 to 79 as Phase 3. The 2 dietary treatments were a control mash diet based on corn and soybean meal and a liquid diet produced by enzymatically digesting food waste and supplemented with vitamin-mineral premix. All diets met the current estimates for nutrient requirements of growing-finishing pigs based on NRC (2012). In phases 1 and 2, pigs were fed either control or liquid diet, while all pigs were fed with control diet during phase 3. At the conclusion of the experiment, one pig per pen were slaughtered and longissimus muscle (LM) was excised from the posterior of the 10^th rib to measure meat quality after chilling 24 h. Back-fat samples were also collected to measure fatty acid profiles. All data were analyzed with PROC MIXED of SAS with pen as experimental unit. The statistical model included diet as fixed effect and block as random effect. The liquid feed tended to decrease (P = 0.087) subjective firmness (2.43 vs. 2.86), but did not impact LM pH, marbling score, and objective color L*, a*, and b*. Pigs fed with the liquid feed contained more (P < 0.05) pentadecanoic acid and margaric acid, and greater (P < 0.05) myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, gondoic acid, EPA, and DHA in back-fat than pigs fed the control diet. Feeding control diet increased (P < 0.05) palmitic acid, arachidic acid, linoleic acid, linolenic acid, and eicosadienoic acid in the back-fat of pigs, compared the liquid feed. In conclusion, feeding enzymatically digested food waste to growing and early finishing pigs did not affect their meat quality and may benefit pork products by providing more beneficial fatty acids to pork consumers.