Maintaining high flock health status is critical to achieving high animal welfare standards, high levels of animal performance and high profitability in lamb production systems.

Today (Thursday, September 24), the focus for Virtual Sheep Week turns its attention to flock health.

Knowledge of the health status of your flock is essential. Timely investigation of sickness/ill-thrift and unexplained deaths in your sheep will give you the tools to maintain a healthy flock.

“Iceberg diseases” in sheep refer to chronic conditions that are insidious in onset and/or spread and have a big impact on the productivity and welfare of the flock.

They may affect ewe longevity and health as well as impacting lamb viability and growth. At the flock health webinar we will have three speakers who have many years of research, knowledge transfer and veterinary experience.

Join Teagasc’s live interactive webinar this evening at 7:00pm with specialists, researchers and guest speakers on:; or Teagasc Facebook; or follow #VirtualSheepWeek on social media for information and advice on maintaining high flock health.

This evening’s panel discussion will be led by Michael Gottstein, Teagasc Sheep Specialist, with panellists Tim Keady, Teagasc Athenry; Orla Keane, Teagasc Grange; and guest speaker Maresa Sheehan from the Department of Agriculture, Food and the Marine.

Tim will discuss the results of his research on mineral nutrition and reducing lamb mortality. Orla will outline ways of reducing the challenge of anthelmintic resistance and how to best use anthelmintics.

Maresa, from the regional veterinary laboratory, will review “iceberg” diseases and strategies to avoid their introduction to a flock.

Topics covered today include

Mineral supplementation

69% of Irish sheep farmers supplement their flock with minerals at least once annually, but only 35% of farmers who supplement base their decision on veterinary advice or laboratory analysis.

Cobalt and selenium are the most important minerals in sheep production. Cobalt is required by sheep for the synthesis of vitamin B12 in the rumen.

Symptoms of deficiency include loss of condition, poor fleece quality, ears becoming dry and scaly, loss of appetite, runny eyes with tear staining on the face, and raised worm counts. Teagasc research has shown that herbage on 73% of sheep farms are deficient in cobalt concentrations.

Lamb mortality

Each 1% change in lamb mortality nationally is worth approximately €3 million annually.

Studies from Athenry show that most lamb mortality occurs within 24 hours of birth with the two main causes, infection and dystocia, being potentially preventable. Tune into this evening’s webinar and learn ways to reduce dystocia and develop good hygiene practices on farm.

The challenge of anthelmintic resistance

On many farms, parasitic roundworms have developed the ability to survive a worm dose that would normally kill them, a phenomenon known as anthelmintic resistance.

Grazing sheep are naturally exposed to parasitic roundworms and infection commonly results in ill-thrift. Good worm control is dependent on effective wormers.

Four key steps to slow the further development of anthelmintic resistance, and that are applicable on most Irish sheep farms, have been identified.

To delay the development of anthelmintic resistance, farmers should follow the following advice:

  1. Don’t dose mature ewes unless there is a demonstrated need;
  2. Use white drenches to control Nematodirus in lambs;
  3. Quarantine drench to prevent ‘buying in’ resistance;
  4. Drench test / faecal egg count.

Iceberg diseases

Iceberg diseases in sheep can be described as a chronic wasting disease that is often insidious in onset, but can be economically costly. They are often referred to as “iceberg diseases”, as the noticeably thin ewes are the visible tip of the iceberg, with the vast majority of their negative impact hidden below the surface.

Such diseases are: OPA – ovine pulmonary adenomatosis / jaagsiekte (retrovirus); Ovine Johne’s disease; Maedi visna (lentivirus); and CLA – caseous lymphadenitis. Learn more today about the prevention of such diseases on your sheep farm.

For more information on Virtual Sheep Week, visit: