AgriSearch have published a booklet summarising the results of six studies on the use of home-grown proteins in dairy cow diets. The studies were carried out by AFBI and funded by the Department of Agriculture, Environmental and Rural Affairs (DAERA) and AgriSearch.

Protein sources such as soya beans and rapeseed meal have traditionally been incorporated in the diet of dairy cattle in Northern Ireland. Such sources, however, have to be imported to Northern Ireland and as a result are subject to price fluctuation and, in the case of soya beans, increasing environmental concern. As a result, a research project to investigate the potential use of homegrown proteins in NI dairy systems was commissioned and funded by the Department of Agriculture, Environmental and Rural Affairs (DAERA) and AgriSearch.

Thomas Steele, AgriSearch Dairy Committee Chairman, said, “The importance of food security and shorter food supply chains has been highlighted by the current Covid-19 pandemic. Imported protein supplements are both expensive and subject to price volatility. In addition, the long-term supply of non-genetically modified protein into Europe cannot be guaranteed. Reducing imports would both increase resilience in the sector and improve the carbon footprint and environmental sustainability of local dairy systems.”

The studies focused on the use of locally grown ‘protein crops’, such as field beans and red clover. The options for partially replacing imported protein feedstuffs with locally grown ‘protein crops’ in the diets of dairy cattle and how this may impact on cow performance were examined. The experiments were titled as follows:

  • Experiment 1: The effect of degree of milling of dry field beans, and acid preservation of moist field beans, on dairy cow production
  • Experiment 2: The impact of including ‘low’ levels of field beans in the diet of mid-lactation dairy cows
  • Experiment 3: The effect of including high levels of field beans in the diet of early lactation dairy cows
  • Experiment 4: Effect of mixing grass silage and red clover silage at four different ratios on cow performance
  • Experiment 5: Milk production potential of silage made from red clover/grass swards
  • Experiment 6: Do red clover swards wilt more slowly than grass swards?

Results from the study are promising, indicating that locally grown protein crops have the potential to replace half of the imported soya currently found in dairy cow diets. In addition, it was also found to significantly reduce the cost of dairy cow diets and have a positive impact on the carbon footprint and sustainability of dairy systems in Northern Ireland.

In addition to summarising each experiment and the outcomes, the booklet also provides an overview of field beans and red clover alongside practical considerations for the use of field beans in dairy cow diets.



The booklet is available to download from the AgriSearch website: