ENVIRONMENTAL IMPACT OF BEEF AND EGG PRODUCTION ACROSS DIFFERENT HUSBANDRY SYSTEMS WITH VARYING WELFARE STANDARDS

Global livestock production has expanded in recent decades, supplying about one-third of dietary protein and one-fifth of caloric intake. However, it is linked to major environmental impacts. At the same time, animal welfare issues have intensified, particularly in intensive systems. Policy reforms on welfare are closely tied to housing systems, which also influence environmental outcomes, though these links are rarely examined. This thesis investigates the relationship between environmental sustainability and animal welfare in beef cattle and laying hens. I propose an approach for jointly quantifying both aspects. The thesis also explores the role of technological innovations, particularly automation. Chapter one analyses beef fattening in the Veneto region. Limousin bulls were housed in barns and fed either once daily with a conventional system or multiple times daily with an automatic feeding system (AFS). AFS increased feeding frequency more than fourfold, promoted more flexible feeding and ruminating patterns resembling grazing cattle, and increased dry matter intake. Growth and carcass performance were similar, but AFS reduced veterinary treatments and ruminal disorders, offering health and welfare benefits. Chapter two assesses environmental impacts of beef fattening using two representative farms with different flooring systems combined with regional data. Life Cycle Assessment, implemented via the HESTIA platform, showed that deep-bedded systems had higher global warming and eutrophication, whereas acidification was greater on slatted floors. Given France’s role as a key supplier of weanlings, trends and projections for imports were included, showing declines and reduced associated emissions. Animal losses contributed substantially to the regional burden, highlighting welfare-environment interactions. Chapter three examines UK egg production, analysing how cage bans could affect environmental outcomes. Seven national-scale scenarios were modelled with cage, barn, free-range, and organic systems. Organic and free-range systems had higher global warming, eutrophication, and acidification per kilogram of eggs, while cage systems showed the lowest mortality and environmental burdens. The current UK mix of production systems outperformed most cage-free alternatives by requiring fewer hens and lower mortality, though it performed less well than fully cage-based systems. Overall, this thesis demonstrates trade-offs between welfare and environmental outcomes and emphasises automation as a promising strategy to improve production.