Just one in five cattle and sheep farms is economically viable, according to a Teagasc sustainability report based on the 2018 Teagasc National Farm Survey.
The report also classes 40pc of beef holdings as "vulnerable" from a household income perspective, and finds that beef farmers are three times more likely than their dairy counterparts to experience social isolation.
Dairying remains the most economically sustainable enterprise, but the report shows that milk suppliers generate four times more CO2 per hectare than cereal growers and five time more ammonia.
While the report notes that 73pc of dairy farms and 62pc of tillage farms are economically viable, the corresponding figures for cattle and sheep holdings are just 18pc and 20pc respectively.
These results are reflected in the average gross margin per hectare figures for the various enterprises.
Dairying has the highest average gross margin at €1,728/ha, followed by tillage at €904/ha. The average gross margin for beef is €483/ha, with sheep on €400/ha.
The report confirms that beef and sheep farmers have the largest proportion with a 'high age profile', with 38pc of those working drystock holdings in this category.
One-third of tillage farmers are also classed as 'high age profile', but the figure for milk suppliers is just 12pc.
A quarter of beef farmers experience social isolation, the study found, compared to 16pc of cereal growers, 13pc of sheep farmers and 7pc of dairy farmers.
The study also illustrates the considerable environmental challenges facing dairy farming.
The report says tillage farmers generated 2.3kg/ha of CO2 in 2018. However, the equivalent figure for dairy farms was 9.2kg. The CO2 figure for beef holdings was 4.5kg/ha, while sheep farms produced 3.7kgs/ha.
Ammonia output from dairy farms was similarly high in comparison to other enterprises, and has continued to increase since the abolition of milk quotas.
The average figure for dairy holdings was 49kgs/ha, with the figure being 23kgs/ha for cattle, 12.8kgs/ha for sheep farms, and 8.8kgs/ha for tillage operations.
Nitrogen usage ranged from an average of 201kgs/ha on dairy farms, to 62kgs/ha on tillage farms. Nitrogen usage on cattle and sheep farms average 70-71kgs/ha.