Adelle writes: What Can Your Sheep Tell You?

The AHDB Beef & Lamb Stocktake report gives us a decent breakdown and summary of production costs, profitability and performance on English Beef and Sheep farms.  The 2015 report recently published is very interesting reading and led me to pondering a question. I am sure you will not be surprised to read that according to this report the average lowland sheep flock has made a loss of just under £7.60 per ewe in 2015 with all costs of production taken into account.

There are many factors we know about that will be contributing to this rather depressing figure, but on farm what are the unknowns that may be limiting flock performance and hence profitability.  More importantly, what can we do to tackle these unknowns?

“A sheep’s main aim in life is to die” – Yes, this is depressing but probably not far from the truth, the list of sheep diseases is almost endless.  Unhealthy sheep are rarely profitable sheep, but some diseases are more obvious (clinical) than others (sub-clinical). Diseases that are often obvious include lameness, abortion and pneumonia.  Normally they are easy to spot and diagnose, and if we know about these problems we can tackle them.

There are also the sub-clinical or iceberg diseases.  These conditions are rarely obvious; the signs can be very subtle and will often go unnoticed.  These diseases tend to rumble along under the surface and limit flock performance without any obvious indication as to what the condition may be.  Sometimes we may see just one clinical case of such a condition (‘the tip of the iceberg’); the danger is that under the surface much of the flock could be battling the condition without our knowledge.

Examples of these iceberg diseases include:

  • Johnes disease – sheep in poor condition and sometimes accompanied by scour, this disease will always result in death if the sheep doesn’t succumb to something else first.
  • OPA (Ovine Pulmonary Adenomatosis/ ‘Jaagsiekte’) – this is an infectious lung tumour spread by a virus, it can cause coughing, weight loss and death.
  • MV (Maedi Visna) – progressive pneumonia and coughing in older sheep and wasting of the nervous system potentially leading to paralysis / head tilt.
  • CLA – the clinical form involves abscesses forming in the lymph nodes of the head, in the sub-clinical form these abscesses can also form internally thus causing weight loss.
  • Undiagnosed internal and external parasite burdens.
  • Nutritional problems such as deficiencies (Iodine deficiency is very common on the farms within our practice).

So, we are often told the first step to getting over a problem is to admit you have one, but what if you don’t even know you have a problem?

This is where dead sheep and cull ewes come in.  Firstly, dead sheep - are they always a dead loss? In some senses they are; in fact they cost money to dispose of, but actually they present an opportunity.  A quick and simple post-mortem examination could un-cover one of these ice-berg diseases within your flock – knowledge of the problem equips us to tackle it.  Cull ewes also present an opportunity; many of them represent the older portion of your flock, so have been on farm for a while, being exposed to infectious agents that may be circulating.  We can test these cull ewes before they go on the lorry, by taking blood samples to look for antibodies to diseases such as Johnes, CLA and MV to name a few. We can also faecal sample these ewes to look for evidence of Johnes and internal parasites.  The knowledge we could gain from sheep towards the ends of their productive lives could really help to improve flock performance and profitability.

What could your sheep tell you if you asked?