The union's claim comes as the Health and Safety Executive begins inspecting farms for the first time since the foot-and-mouth crisis.
But it also comes as new research indicates only one in 67 farmers in Cumbria quit the industry following the crisis.
Farming has one of the worst safety records of any UK industry.
On average one person dies in a farming accident every week, despite the increase in health and safety legislation.
The NFU says the high number of fatalities is due to the pressure its members are under.
Hard labour
The foot-and-mouth crisis has forced many farmers to get rid of staff.
Those who are left work longer hours and do more of the hard manual labour themselves.
Often, farmland is handed down through generations and farmers are reluctant to let it go.
This is borne out in the findings of research carried out by Newcastle University.
A team from its Centre for Rural Economy has been studying the social and economic impact of the foot-and-mouth crisis in Cumbria - one of the worst-hit area of Britain.
It found that only one out of 67 farmers questioned had quit the industry since the 2001 outbreak.
Dr Katy Bennett, one of the authors of the report, told BBC Radio 4's Today Programme: "That was a surprise for us, Things were extremely hard for farmers."
Meanwhile, officials from the HSE hope that by resuming visits now, they will be able to improve safety across the industry.