Reducing the crude protein content in pig diets can lead to significant reductions in ammonia emissions, a new study has concluded.

Researchers at AFBI Hillsborough examined the effect of three different finishing rations on ammonia emissions and pig performance. The rations had high (180g/kg), medium (150g/kg), and low (130g/kg) crude protein levels.

Compared to the high-crude-protein diet, the medium ration led to a 22% reduction in ammonia emissions and it fell by 47% with the low-protein ration.

The study, which was published in the scientific journal Sustainability, states there was “no significant effect of reducing crude protein on performance”.

The AFBI researchers also found that water usage and slurry production, as well as nitrogen and phosphate levels in slurry, all reduced in line with dietary crude protein levels.