Figures supplied to Agriland by the Department of Agriculture, Food and the Marine (DAFM) show that 55% of the lymph node glands that were submitted for analysis from beef factories in 2021 were found to be negative for bovine tuberculosis (TB).
In 2020, 53% of the lymph node glands from DAFM-approved factories that were submitted for analysis were found to be negative for TB.
The department told Agriland: “All cattle processed are subjected to a high-level gross post-mortem veterinary examination, including an examination of lymph nodes for TB.
“When a suspected lesion is detected at post-mortem examination, the lymph node glands are sent to the Central Veterinary Research Laboratory in Backweston, Co. Kildare, for confirmatory examination.
“This examination includes histopathology and culture for TB.
“In 2020 and 2021 respectively, 2,005 and 2,047 of such lymph node glands submitted were positive for TB. This represented 47% and 45% respectively of suspected samples submitted for analysis from DAFM-approved factories in those years.”
The department outlined that the disease causes significant hardship for farmers and farming families.
It also affirmed that it “is fully committed” to reducing the impact the disease has on farm families in Ireland, and said that the Bovine TB Eradication Strategy aims “to reduce and ultimately eradicate” the disease in Ireland.
The DAFM said that the Bovine TB eradication programme is the largest animal health programme in the country, costing in the region of €100 million/year.
The DAFM added that while the incidence of the disease is now low, relative to historical levels, the number of new restrictions and reactor numbers gradually increased between 2016 and 2020.
It also said there were encouraging signs in 2021, as TB levels were lower than in 2020, with fewer reactors and a lower herd incidence.
Herd incidence at the end of 2021 was 4.33% compared to 4.38% at end of 2020. However, areas of north Cork, Meath, Wicklow and Monaghan are experiencing higher levels of disease than others, according to DAFM.
Figures to date for 2022 show signs of improvement with herd incidence, on a rolling 12-month basis (October 3), standing at 4.12%, the department said.
Causes of TB case increases
The DAFM has said the increase in disease levels over the past number of years is down to a combination of national and local factors.
The department noted that the expansion of the dairy herd since 2015 has had an impact on TB levels.
It added: “Dairy herds, larger herds, fragmented farms, and herds that buy-in cattle are all more at risk of a TB breakdown.”
It added that “wildlife can also be a factor”.
“The department’s policy divisions are supported by the 16 Regional Veterinary Offices throughout the country, each of which prioritises TB management,” it continued.
“The TB programme in each county focuses on factors including wildlife; how disease is distributed in the area; contiguous programmes; gamma interferon testing; cleansing and disinfection; testing compliance; and swift isolation and removal of reactors.”
According to the department, each disease outbreak is investigated by a veterinary inspector to identify the source of infection.
It said in the case of every outbreak involving two or more standard reactors, there is a veterinary visit to advise the herd owner on how to eliminate infection and measures necessary to help reduce the risk of recurrence.
The DAFM said that emphasis is placed on the biosecurity measures that a farmer can take to reduce risks on his or her farm, and when buying in animals.
The department has detailed that in an area that shows a significant increase in TB levels, the regional veterinary office (RVO) implements a high-impact TB control plan and works with farmers and other stakeholders to reduce levels of TB in those areas.
It added that these control plans involve increased levels of testing and other control measures. The department said intensified co-operation and collaboration with local famers and other stakeholders in these areas helps to reduce the level of disease.
New strategy
In 2021, the Minister for Agriculture, Food and the Marine, Charlie McConalogue, launched a new Bovine TB Eradication Strategy (2021-2030).
The implementation of this strategy is overseen by the Bovine TB Stakeholders Forum which is supported by three working groups on science, implementation and finance.
According to the DAFM, Ireland’s bovine TB Eradication Programme operates in line with “best national and international scientific research and advice”.
Research contained in the strategy document outlines that the principle causes of TB introduction and spread include:
- Movement of cattle with undetected infection;
- Residual infection in cattle previously exposed to TB, but not identified at time of test;
- Spread across farm boundaries;
- Indirect spread through other biosecurity breaches;
- Spread from infected badgers to cattle.
The department has indicated that in order for Ireland to make “substantial” further progress on TB in the 2023-2025 period, additional steps to build on the current strategy will be needed and a number of options are now under consideration by the Bovine TB Stakeholders Forum.