This is a drop of 50% from the £83,800 (€94,060) average farm income dairy farmers were receiving in 2014/15.
It attributes the drop in income almost entirely to a reduced milk output driven by a 25% fall in average price but partially offset by a higher volume.
This is a greater price fall than the 21% seen across the UK for the same period based on national milk price statistics.
Agricultural costs (both fixed and variable) were also lower on dairy farms compared to other enterprises, the most significant of these being a 20% reduction in purchased feed and fodder, according to DEFRA.
Of the fixed costs, it found that lower machinery depreciation and running costs were the most significant.
Irish Dairy Farm Incomes
Meanwhile, the latest Teagasc National Farm Survey found that dairy farm incomes in Ireland also fell in 2015, but not by as much as their English counterparts.
In 2015, while milk prices were down by almost 20%, income on dairy farms fell by just 4% to an average of €63,020.
However, while the drop in income was not as steep as it was in England, Irish dairy farmers had to produce 20% more last year to maintain the same income levels of 2014.
Almost one in three dairy farms increased their milk production by 20% or more, with just one-fifth of farms choosing to reduce production levels in 2015.
A total of 56% of Irish dairy farms earned over €50,000 in 2015, according to the survey.