Effects of adding a dried food waste product to the diets of finishing pigs on growth, feed intake, and nutrient digestibility
A study was conducted to measure the effects of adding a dried food waste product (DFWP) to the diets of late finishing pigs. The product was derived from bakery and vegetable food waste being aerobically digested (BioGreen 360) and heated to over 150 degrees Celsius during drying. Prior to mixing the diets, the DFWP used in the study was analyzed for nutrient content and found to have 84.0% DM, 10.95% CP, 15.42% EE, 0.42% Lys, 0.17% Ca, and 0.22% P. Nine finishing pigs (132 kg BW) were allotted randomly to one of three dietary treatments: 1) corn-SBM-based control diet; 2) control with 5% DFWP added; and 3) control with 10% DFWP added. All diets were balanced for lysine, Ca, and P (NRC, 2012). The study was conducted in three one-week periods, with each pig being fed a different diet each week with a 5-day adjustment period followed by a 2-day collection of feces. Pigs were weighed weekly and feed disappearance was measured daily. Fecal grab samples were dried and analyzed for DM, CP, EE, and ADF. Acid-insoluble ash was used as an indigestible marker for digestibility calculations. During the experiment, average daily gain (ADG) increased linearly (P<0.05) with increasing DFWP addition to the diet. Average daily feed intake (ADFI) decreased numerically in pigs fed diets with 10% DFWP, as expected due to the high fat content of DFWP. Digestibility estimates for DM, CP, fat, and ADF were not influenced by collection period and were pooled across period to estimate the effect of dietary DFWP addition. DM digestibility averaged 94.6% for all diets and was not influenced (P>0.10) by DFWP addition. CP digestibility was also not affected (P>0.10) by DFWP addition to the diet and were 81.1%, 81.2%, and 80.9% for Diets 1, 2, and 3, respectively. Fat digestibility (51.9%, 55.3%, and 62.8% for Diets 1, 2, and 3, respectively) increased linearly (P<0.01) with increasing DFWP addition to the diet and was higher (P<0.10) than the control diet when 5% or 10% DFWP was added. ADF digestibility was not affected (P>0.10) by DFWP addition to the diet. Based on this experiment, the DFWP produced by the Biogreen 360 food waste digester is palatable for growing pigs, increases the fat digestibility of a corn-SBM based diet, and does not negatively influence protein or ADF digestibility when added up to 10% of the diet.
Keywords: Pigs, Food Waste, Digestibility