Nutrient management for resilience

Funding period: 2024-2027
Lead: Mélissa Duplessis
Total GRDI funding: $1,602,934

Consumer awareness of cow welfare has led to constant increased adoption of dairy free-stall barns over the last decades. In return, free stalls are associated with more infectious foot lesions caused by bacteria such as digital dermatitis (DD) due to more foot contact with feces and humidity. A solution to prevent DD, implemented in about 87% of Canadian free-stall herds, consists in the use of footbaths with trace nutrient (TN) products such as copper sulfate as an antimicrobial agent. Dairy producers are facing a dilemma with TN products: 1) they have been proven to be the most effective to prevent DD, this disease causing a yearly financial loss of $22 million and 2) their disposal in manure tanks causes TN build up in the environment with manure spreading, soil and water toxicity and co-selection for metal/antimicrobial resistant bacteria. After decades of releasing TN products in the environment through manure application, long-lasting impacts of high levels of TN in their soils are not known. As the use of footbath TN products continues to increase in Canada, ignoring the environmental impacts of releasing large quantities of TN into our agro-ecosystems represents a risk for sustainability. There is currently no point of comparison to inform producers if the TN concentrations of their manure, soil, crop and water are problematic for agro-ecosystem health. No Canadian data yet exist to relate the impacts of footbath TN product use on agro-ecosystems and human and animal health. Producers are increasingly conscious that this management can have deleterious impacts on agro-ecosystems but the lack of effective alternatives forces them to continue using footbath TN products. This project will evaluate an affordable clean-filtration technique, easily transferable on farms, to recycle and reuse TN products from waste footbath solutions by purifying them from organic matter and bacteria. This will in turn improve farm profitability by reducing costs of non-renewable TN product purchase, lowering the environmental impact of TN build-up and favoring a positive consumer perception of dairy production. By preventing DD, results of this project will then contribute to increased cow longevity and productivity. This improved efficiency will help dairy producers work towards their goal of achieving net-zero GHG emissions by 2050.