Improved pork quality and pig performance through a circular feeding strategy: A sustainable approach

The increasing global demand for animal protein places additional pressure on feed-food competition and the environment due to greenhouse gas emissions. In this study, a circular, low-carbon-footprint (LCF) diet containing former food products from the bakery and pastry sector was evaluated. The experiment had a randomized complete block design with two dietary treatments consisting of a control (CON) and a LCF diet. A total of 240 pigs (25.1 ± 1.56 kg) were fed either the CON or LCF diet for 90–92 days. Growth performance, carcass weight, dressing percentage, backfat thickness, muscle depth, and lean meat percentage were assessed after slaughter. Meat shelf life and fatty acid composition were evaluated for up to 13 days after packaging of the meat samples, alongside sensory attribute analysis. A life cycle assessment (LCA) was conducted to assess the environmental footprint of the diets. Feeding the pigs the LCF diet resulted in improved growth performance when compared to the CON diet. Additionally, it improved carcass weight, dressing percentage, back-fat thickness but decreased muscle depth. Although meat freshness decreased with time after packaging, the olfactory sensory analysis indicated an improvement in the LCF group, combined with greater redness of the meat and improved oxidative stability, whereas meat from the CON group had a lighter color. Regarding fatty acids composition, the LCF diet increased the content of C18:3, C20:1, C20:5, and n-3, whereas decreased C17:0 levels in the meat. Given the LCA data, the LCF diet minimized the impacts of climate change.