Utilization of Enzymatically Digested Food Waste in Growing-Finishing Pigs. 1. Growth Performance, Visceral Mass, and Carcass Characteristics

Enzymatic digestion is a technology that can be used to convert food waste from supermarkets into pasteurized liquid pig feed. The objective of this experiment was to examine the effects of feeding enzymatically digested food waste on growth performance, visceral mass, and carcass characteristics of growing and finishing pigs. Fifty-six crossbred pigs (approximately 32.99 kg BW) were randomly assigned to one of 2 dietary treatments with 7 replication 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 control diet based on corn and soybean meal and a liquid diet produced from enzymatically digested food waste that was only supplemented with vitamin-mineral premix. In phases 1 and 2, pigs were fed control or liquid diet, while all pigs were fed with control diet during phase 3. Pigs were weighed on d 0, 28, 53, and 79. Daily feed allotments were recorded and all diets were analyzed for DM to calculate ADG, average daily dry matter intake (ADDMI), and Gain:Feed. At the end of the experiment, one pig with the BW closest to the average BW of the pen were slaughtered to measure viscera mass and carcass characteristics. All data were analyzed with PROC MIXED of SAS with pen as experimental unit. Feeding liquid feed reduced (P < 0.05) pig BW on d 28, 53, and 79 and reduced (P<0.05) ADG on phase 1. This observation was likely due to the reduced (P < 0.05) ADDMI on phases 1 and 2. Pigs fed enzymatically digested food waste tended to increase (P = 0.082) Gain:Feed by 4.1% on phase 3. Pigs fed with the liquid feed had bigger (P < 0.05) gastrointestinal tract including stomach, small intestine, and large intestine than the pigs fed with the control diet. Hot carcass weight was lower (P < 0.05) in pigs fed the liquid diet due to the smaller ending live weight. However, no differences were observed in carcass yield and other carcass measurements. In conclusion, the high moisture content in the enzymatically digested food waste limits the growth performance of growing pigs. However, it is believed that this byproduct could provide nutrients match or even exceed the nutrient contents in corn-soybean meal diet after increasing DM content.