Improving the environmental sustainability of dairy farming through improved nutrition

The impact of excess phosphorus on water quality was demonstrated by algae blooms on Lough Neagh during summer of 2023.

Nitrogen causes problems when it pollutes waterways (in the form of nitrates), is deposited on sensitive habitats (in the form or ammonia) and enters the atmosphere as nitrous oxide (a potent greenhouse gas).

Methane, another greenhouse gas, is emitted from a wide range of sources, but mainly from ruminant livestock systems.

While existing legislation requires Northern Ireland takes action to reduce these emissions, there is particular pressure on the agriculture sector given the intensity of agricultural emissions.

Fortunately, there are approaches which can be adopted to address these issues without having an adverse effect on cow performance, with many of these being examined within research programmes at AFBI Hillsborough.

Adopting lower phosphorus diets has been shown to reduce phosphorus excretion in manure by up to 45%. A further reduction in the phosphorus content of dairy cow concentrates, from the agreed target of 5.7 g/kg to 5.2 g/kg (fresh) could reduce quantities of excess phosphorus on local dairy farms by approximately 350 tonnes per year.

Reducing the crude protein content of the diet can reduce nitrogen excretion in manure by around 15%, and ammonia emissions from the resultant slurry by up to 30%.

Furthermore, research across many countries has demonstrated that methane supressing feed supplements can reduce methane emissions from cows by 5 - 30%.

If we are to reduce the environmental impact of dairy systems within Northern Ireland, all of these approaches will increasingly have to be adopted.

At the dairy Farming for the Future open day on 18th June, the AFBI Hillsborough dairy research team will outline nutritional approaches which can be adopted to help reduce nitrogen, phosphorus and methane losses from dairy systems.

The open day will also offer the opportunity to hear about the latest research findings on grassland management, soil health, animal health, welfare and genetics, slurry management, as well as an opportunity to view the recently established platform demonstrating opportunities for increasing biomass on farms.

Don’t miss this opportunity to get updated on recent research findings across a wide range of topics aligned with dairy farming.

For more information on this dairy open day on Tuesday 18th June, or on the beef and sheep open day on Wednesday 19th June, please register at https://www.afbini.gov.uk/events.