CattleReview

There is considerable evidence that improving productivity reduces environmental impacts from livestock production. However, despite the negative impacts of animal diseases on reproduction, growth and milk production, there is little information available on the impacts of animal disease on greenhouse gas emissions (GHGe). This study by Capper (2023) (10.1186/s42522-023-00089-y) aimed to partially address this knowledge gap by investigating the effects of globally important vaccine-preventable diseases on GHGe from various livestock systems, namely: intensive dairy, extensive beef, commercial swine and backyard poultry. Simple deterministic models were developed to quantify the impacts of livestock disease on productivity (defined as total milk and/or meat yield, MMY) adjusted for disease prevalence both at the population level (high or low) and at the herd or flock level. Disease-induced changes in MMY were applied to the GHGe per kg of milk or meat according to the consequent changes in live-stock populations required to maintain milk or meat production. Diseases investigated comprised foot and mouth, brucellosis, anthrax, lumpy skin disease, classical swine fever, porcine reproductive and respiratory syndrome, low and high pathogenicity avian influenza, avian infectious bronchitis and Newcastle disease. All diseases investigated had multifactorial impacts on total MMY, yet diseases that increased mortality in breeding or growing livestock (eg anthrax, classical swine fever and high pathogenicity avian influenza) showed greater impacts on GHGe per unit of milk or meat produced than those that primarily affect yields or reproduction (eg brucellosis or low pathogenicity avian influenza). Prevalence also had considerable effects on potential GHGe. Effective reduction of the prevalence of porcine reproductive and respiratory syndrome from 60 to 10%, foot and mouth in beef cattle from 45 to 5%, or avian infectious bronchitis in poultry from 75 to 20% would reduce GHGe by 22.5%, 9.11% and 11.3% respectively. Controlling livestock disease can reduce MMY losses at the farm level, which improves food security, reduces GHGe and enhances livestock system sustainability.