Effects of dietary supplementation with potato and grocery store residues on the zootechnical performance and odor and gas emissions of growing-finishing pigs

Abstract. In developing countries, the pre-consuming waste can reach 30% of the vegetable produced by the farmers. This lost happened at different levels of the food chain (field, storage, transportation and grocery). In many countries, these agricultural residues are managed like a waste even if it is still consumable. On another hand, the livestock producers are always looking for a way to reduce feeding costs. The goal of the research program is to reduce spillage and environmental impact of the overall food chain. More specifically, the project objective was to study the effect of two alternative pig diets containing respectively 15% of potato and 15% of grocery residue on 1) growth pig performance and 2) gas and odor emissions. The potato and the grocery residues have been grinded, dried and pelletized. Three diets have been formulated to be iso-nitrogenous and iso-caloric. An experimental setup of twelve independent rooms each housing three castrated pigs have been used to compare the effect of the treatment combinations for six weeks. The odors have been measured during the trial by a nasal-ranging approach and by olfactometry. The treatment had no significant effect on the feed, water intake but had a significant effect on weight gain (P=0.0715). The gain mean was slightly higher for the control M (45.0 kg) compared to MP (41.2 kg) and MR (41.9 kg). Gas emissions were not affected by treatments. Higher odor emissions were produced by MP and MR, however intensities were lower or less irritant. These results confirm the feasibility to develop alternative diets using downgraded potatoes or vegetable wastes from grocery store. However, these residues have to be dried and processed and an economical study should be done to validate this feasibility.