Table 2.

A summary of selected studies reporting effects of adding food waste to poultry and pig diets.

Animal Model	Study Design	Key Findings as Reported by Authors	Reference
Broiler (Ross)	Diets contained 0%, 10%, 20%, or 30% dried leftover food (DLF) or 10% DLF and 5% higher protein level (PL), 20% DLF and 10% higher PL or 30% DLF and 15% higher PL than control diet	DLF contained 20.62% CP, and 9.99% EE DHA content was numerically higher in meat of DLF groups, but was not significantly different EPA content in meat was significantly higher in meat of the 30% DLF, 10% DLF and 5% higher PL, and 30% DLF and 15% higher PL groups compared to the control group Linolenic acid content in meat was numerically higher in DLF groups, though significantly higher in 10% and 30% DLF treatments, and in 10% DLF and 5% higher PL, and 20% DLF and 10% higher PL groups compared to the control group Linoleic acid content in meat was numerically higher in DLF groups, though significantly higher in 10% DLF, and 10% DLF and 5% higher PL groups compared to the control group Myristic acid content in meat was significantly higher in 10% DLF and 5% higher PL group Palmitic acid content in meat presented no significant differences among treatments Palmitoleic acid (C16:1) content in meat was significantly lower in 10% DLF, and DLF and higher PL groups compared to the control group Arachidonic acid content in broiler meat showed no significant differences among treatments. Cholesterol concentration in broiler meat was numerically higher in groups fed diets containing 10% or 20% DLF (101.18 and 102.12 mg/g, respectively) compared to the control group (92 mg/g)	[39]
Free range village chickens	Diets contained dehydrated restaurant waste (RW) at 0%, 20%, 40% or 60% level	RW had a higher proportion of SFA than the diet of the control group SFA content in meat was significantly higher in groups fed RW PUFA content in meat decreased linearly with increasing inclusion of RW in the diet PUFA/SFA ratio decreased with increasing incorporation of RW in diets The minimum PUFA/SFA ratio was found in group fed diet containing 60% RW, which increased with decreasing inclusion of RW in the diet n-6 fatty acid content decreased with increasing inclusion of RW in diet, while the n-3 fatty acid content increased	[76]
Laying hens	Diets contained 0%, 12.5%, 25% or 50% dehydrated kitchen waste product	The dehydrated kitchen waste product had 15.14% CP, and 5.33% EE PUFA content was the highest in egg yolk from hens fed diet containing 50% kitchen waste, while SFA was the lowest compared to control C18:1 and C18:3 content in egg yolk tended to elevate with increasing incorporation of kitchen waste in diets.	[77]
Swine	Control group was fed a conventional diet, and experimental group was fed solely boiled restaurant waste during the growing (6 wk) and finishing period (12 wk) and then the conventional feed for 4 wk before slaughtering	CP and total lipids of RW were 26.59% and 7.33%, respectively CP and total lipids of the conventional diet were 20.21% and 15.67%, respectively PUFA content in RW vs. control feed was 25.08% vs. 21.04% while PUFA/SFA ratio was 0.73 vs. 0.57 Positive correlation of fatty acid profile between RW and pork loin, and backfat PUFA content in pork loin compared to the control group was 22% vs. 15.21% and PUFA/SFA ratio 0.6 vs 0.38 was significantly higher, while SFA (37.04% vs. 40.04%) and monounsaturated fatty acid content (MUFA, 40.96% vs. 44.75%) was significantly lower in the experimental group Back fat in swine fed RW showed similar results with those of loin regarding the fatty acid profile with SFA being the exception Lipid peroxidation of pork loin was higher in the group fed RW In comparison to control, pork loin of swine fed RW had higher concentration of EPA (0.44% vs. 0.09%), DHA (0.71% vs. 0.23%), linoleic acid (17.91% vs. 12.68%), and linolenic acid (1.17% vs. 0.61%) EPA (0.13% vs. 0.04%), DHA (0.52% vs. 0.17%), linoleic acid (18.48% vs. 13.65%), and linolenic acid (1.58% vs. 0.91%) content in backfat was significantly higher than that of the control group Arachidonic acid content in loin and backfat was similar in both the control and experimental groups	[44]
Swine	Diets contained 0%, 25%, or 50% food waste mixture and a corn-soy diet	Percentage of total SFA and USFA, MUFA/SFA and PUFA/SFA ratios of longissimus muscle were not affected by the incorporation of the food waste mixture	[40]

CF = crude fiber; CP = crude protein; DLF = dried leftover food; DHA = Docosahexaenoic acid; EE = ether extract; EPA = Eicosapentaenoic acid; MUFA = monounsaturated fatty acid; PL = protein level; PUFA = polyunsaturated fatty acid; RW = restaurant waste; SFA = saturated fatty acid; USFA = unsaturated fatty acid