The curious case of cobalt…

In the late 19th and early 20th Century, sheep farmers across the world became increasingly aware of a devastating disease that caused their sheep to literally waste away and die.

Initial symptoms of the disease were a general failure of the animals to thrive, they also developed an abnormally coarse fleece. 

The disease went by many names specific to the locality where it occurred.  In the UK it was most commonly called pine, or pining disease – because the animals just seemed to give up the will to live, as though they were pining.  Other names included bush sickness and coast disease.

Stockmen had soon realised that the disease was associated with specific soils and geographic areas.  They also found that if they could move the stock to different pasture, they would sometimes recover with no further intervention. 

Initially, scientists thought the disease was caused by a deficiency of iron.  However, in the 1930s this theory was disproved and cobalt was identified as being the deficient nutrient. 

That’s all a long time ago, but I was reminded of it when the vet at a farm I was working on last year recommended giving the sheep B12 injections.  Coincidentally, at the same time a surprisingly large number of my friends, and their friends and families, had been given vitamin B12 injections by their doctors. 

Few farms bother testing their soils at all, and those that do generally only test for pH (to see if they need to lime) and maybe Phosphorous (P) and Potassium (K).  Hence, few if any would know whether their soils were deficient in cobalt (or any other micronutrient).

And what does that have to do with B12?  Well, cobalt is an essential constituent of vitamin B12; another name of B12 is cobalamin.  In ruminant animals, like sheep, cobalt is needed by the bacteria that live in the animal’s rumen and carry out most of their digestion.  These bacteria also synthesise vitamin B12 which is absorbed by the animal.  So, a deficiency of cobalt is thought to adversely affect ruminants through reducing digestive efficiency and causing B12 deficiency.*

In humans, B12 is essential for red blood cell formation and energy production (amongst lots of other things).  Humans need to obtain an adequate amount of vitamin B12 in their diet and the best natural sources are red meat, eggs, fish and dairy products.  A lack of B12 causes a type of anaemia.

So, maybe if the soil is deficient in cobalt meaning the lambs are needing an injection of B12, perhaps their meat, and the milk products from the dairy herd, are also going to be lower in B12 than might be expected.  And maybe that’s why so many people have been needing B12 injections lately…

The role of cobalt in plant nutrition is poorly understood, except for that in nitrogen fixing plants it plays a critical role for the nitrogen fixing bacteria.  Research is still on-going to find out more about its role in non-nitrogen fixing plants.

The take home message of this story is that the interactions between soil, plants/crops, livestock and human nutrition are incredibly complex and fascinating.  There are at least 15 essential mineral elements involved in plant nutrition – and that number tends to keep on increasing as scientists develop a better understanding of plant nutrition.

* for useful information on cobalt deficiency in sheep see the Teagasc factsheet at


Food safety – quality assurance for growers

Hypothetically speaking, if someone fell ill as a result of a food-borne pathogen (perhaps e-coli or clostridium) after eating your produce and the finger of blame was pointed at you, how confident would you be that you were in the clear? And how easily could you convince the authorities of this?

Nobody likes unnecessary paperwork and bureaucracy, but in a situation where your production processes are being called into question, having a robust set of procedures in place with appropriate records and documentation will be your first and strongest line of defence.

In the UK, if your produce is going to one of the major retailers, they will insist on you having appropriate production, harvesting and storage protocols in place before they will buy from you.  This may seem like an unnecessary burden and cost, but it protects you as well as the retailer and ultimately the consumer.

Those who sell via other routes (e.g. to wholesale, direct to the consumer or via independent retailers) will seldom be asked to produce evidence that “due diligence” has been used at all stages of producing their crops.  While this is a “nice” and “friendly” approach that often relies on trust, it will be of no use at all if something goes wrong.

Putting food safety quality control processes into place doesn’t need to be overly complex, nor does it have to be costly.  There is no particular reason why you should use a paid for accreditation system if you don’t need or want to.  The advantage of using one of the recognised accredited systems is that they are “fit for purpose”.  That provides an enhanced level of confidence to both you and your buyers.  But if you want to set up your own system there is nothing to stop you, and any kind of system is better than none.

Even with the best systems in place, things sometimes go wrong.  Having a food safety quality control system in operation is not a cast-iron guarantee for your produce.  What it does do is demonstrate that you have considered the risks and put into place measures to address them. Doing that is a legal requirement as a primary producer: but without documentation how can you ever demonstrate that you were acting with due diligence?

Don’t take risks with your business or your customers’ health: put a food safety quality control plan into place and into practice now!

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Selling culinary herbs – things you need to know first

Herbs are one of the most pleasurable crops to grow.  They’re also great for selling, but, there are some tricky legislative considerations you ought to bear in mind if you are selling herbs.  The legislation may be infuriating, but it’s also bizarrely interesting.  For example do you know which herbs are “allowed” to be sold by the bunch, rather than by weight?  Read on to find out…

Primary product or food
Since 2006, the EU Food Hygiene Regulations have applied to primary producers (i.e. growers and farmers) as well as food producers and processors.  Culinary herbs fall under these regulations.  In their raw, unprocessed state, culinary herbs are primary products (not food).

The regulations mean that as a primary producer you have a duty of care to ensure your produce is fit for purpose.  Particularly you must avoid it being contaminated by things like soil, chemicals, non-potable water, etc.  You must keep records that demonstrate how you have ensured the produce is as safe as possible.  This will include detailed records of any plant protection products used, when they were applied, why, at what rate, etc. – this type of record should always be kept anyway if you are using sprays and chemicals. 

If your holding doesn’t already have a Customer Reference Number (CRN) or County Parish Holding Number (also known as a CPH number, or Holding Number) you will have to register with your Local Authority as a Primary Producer.

When is a herb a food?
Primary products become food once they have been processed.  In general, fresh herbs sold with little or no processing will remain as primary products.  However, dried herbs are considered to have been processed and are therefore classed as food.  Food products have far more onerous regulatory requirements than horticultural primary products.  Washing (with potable water) and trimming will not usually be considered to turn a primary product into food, but do check with your Local Authority to find out how they interpret the Regulations

By the bunch?
Most foods must be sold by weight, but chives, mint, watercress and parsley can be sold by the bunch, without a weight.  For other herbs, if sold in weights of more than 5g (about 1/6th of an ounce – almost nothing), you get into the realms of selling by weight.  For this, you need to make sure that you have suitable scales with calibration records to prove their accuracy.

There are many sad stories of producers printing off sheets of labels only to be told they were non-compliant and therefore unusable.  Labelling regulations are complex.  Essential information for pre-packed herbs is: the name of the herb (plus any additives if appropriate); the business name and address; and the net weight of the product.  For packs of up to 50g the writing must be at least 2mm in height.

Do the regulations always apply (is there wriggle room)?
Direct supply by the producer to the final consumer or to local retailers may fall outside the scope of the Regulations.  However it’s always better safe than sorry, so you should use best practice and comply as far as you possibly can anyway.  Ignorance is no defence in the eyes of the law.

Because the regulations are so complex, you should seek more advice from your local Trading Standards Office (about weights & measures, packaging, etc) and Environmental Health Office (for food hygiene information).  They are almost always helpful and friendly.  They would rather work with you and avoid problems arising than have to take enforcement action.
This information is provided as general guidance only and is no way comprehensive or a replacement for professional advice.