The Department of Agriculture says it is launching an investigation into breaches of animal welfare regulations at several cattle marts, on foot of undercover footage gathered by an RTÉ team.
Journalists with RTÉ Investigates captured footage of young calves being kicked, dragged, thrown, and hit using sticks in several marts around the country.
'Milking It: Dairy's Dirty Secret’ is to be broadcast on RTÉ One television on Monday at 9.35pm.
The programme examines the surge in calves being born in Ireland as a result of the expansion of the dairy sector.
The use of sticks on young calves is strictly forbidden under animal welfare regulations. In one piece of footage filmed by RTÉ Investigates a mart worker can be seen throwing small calves from a trailer as they are being delivered for a sale.
The behaviour featured in the report has been described as "illegal" by a spokesperson for the Irish Co-operative Organisation Society (ICOS), which represents marts.
Ray Doyle of ICOS Livestock & Environmental Executive told RTÉ Investigates, "The issue of just having a stick in your hand for any calf under 42 days of age is illegal."
"Pulling and dragging them and throwing them is illegal. So, I would have no issue for the full rigours of law on these individuals," he said.
Read more: 61 hours: The journey endured by thousands of Irish bull calves
In an email sent to RTÉ Investigates, the Department of Agriculture, Food and Marine (DAFM) has requested the video footage gathered and confirmed it is launching an investigation.
"DAFM condemns any mistreatment of animals, and we take reports of animal welfare abuses seriously," the email states."As the information that you have provided suggests that avoidable pain and/or suffering has been caused to animals, DAFM, as the competent authority, will initiate an investigation into these matters."
The programme also goes undercover to investigate the live export of hundreds of calves to mainland Europe.
The RTÉ team followed a consignment of calves as they were transported by truck from Wicklow to Cherbourg in France, and on to Barcelona in Spain.
The calves received minimal breaks and were not rested for the mandatory periods under EU regulations. Driver time limits were also breached. The company involved to says an ‘internal investigation’ into the journey has been launched.
The programme will also examine how young bull calves which are not exported are disposed of by knackeries and regulated food processing plants in Ireland.
Details of the true extent of the environmental impact of diary expansion will also be explored, with senior figures in the industry conceding that the expansion plans set out by Government did not fully take account of the impact on emissions and water quality.
Read more: The climate cost of Ireland's dairy boom
"We probably needed to take the environment and water quality more serious ten years ago than we have, and we're coming that little bit late to that," ICMSA president Pat McCormack said
The programme will also reveal details of the number of fish kills linked to agricultural emissions in recent years.
RTÉ Investigates: 'Milking it: Dairy’s Dirty Secret' presented by Prime Time's Fran McNulty is broadcast on RTÉ One television on Monday July 10 at 9.35pm