The effects of deer eating OSR

colc08

Well-Known Member
I recently read an article about the effects that oil seed rape can have on deer if they eat it (cannot remember for the life of me now where the article was). The long and short of it was that deer can be greatly effected and it can caused blindness and potentially death, or along those lines. The article made reference to 'Rape' but never clarifies whether it was the leaf of the plant or indeed the seed. So I was wondering which of these two it was that caused the unpleasant after effects after being eaten by deer, does anyone know the answer?
 

brunel-999

Well-Known Member
I recently read an article about the effects that oil seed rape can have on deer if they eat it (cannot remember for the life of me now where the article was).
When I did my DSC-1 6 years ago, we were told this as part of the lectures.

Since then, I have seen Fallow deer on the farm where I shoot, eat substantial amounts of Oil Seed Rape, with no apparent ill effects whatsoever.

I would be grateful if anybody has any information if the effects of OSR vary between the different species of deer.
 

Monkey Spanker

Well-Known Member
Young rape plants at this time of year don't seem to cause much of a problem. It is when they eat it when it is older it seems to cause problems.
I seem to remember reading that it was GM rape that was the worst offender?
MS
 

Tim.243

Well-Known Member
Young rape plants at this time of year don't seem to cause much of a problem. It is when they eat it when it is older it seems to cause problems.
I seem to remember reading that it was GM rape that was the worst offender?
MS
In the my area the farmers have only just drilled it, so until we get rain the there will be no young plants for a good while.
If you are talking about self sown rape then those plants for them to graze on.

Tim.243
 
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Highlandsjohn

Well-Known Member
,The osr was drilled a month ago with us,the stubble ploughed under the same day the barley was cut :( Its peeping through now.
I put the camera up and l guarantee the little buggers will have been out for a midnight feast already.
l had a four yo buck on Tuesday night off the inch high winter barley. They love fresh but I believe too much in the winter months can kill them, it certainly will if I see them eating it...
 

Buchan

Well-Known Member
After reading the original post, I set about trying to find why the deer are blind, and there are surprisingly few decent references. The main toxicity for deer (and livestock) is from the chemical SMCO ([FONT=Arial, Helvetica]S-methylcysteine sulfoxide) which [/FONT]metabolises to dimethyl suphoxide. This damages red cells and causes an anaemia. However brassicas are full of other toxins and the most likely explanation for blindness is sulphur compounds in the rumen that block thiamine (Vitamin B1). B1 is essential for glucose production and as nerves can only metabolise glucose (ie not fat) they suffer most and the animal is blind.

I'm curious if the animals seen are actually blind and not just extremely slow due to the anaemia.

GM status is irrelvant.
 
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rodp

Well-Known Member
After reading the OP, I set about trying to find why the deer are blind, and there are surprisingly few decent references. The SMCO in brassicas metabolises to dimethyl suphoxide and causes an anaemia which is the principle problem. However brassicas are full of other toxins and the most likely explanation for blindness is sulphur compounds in the rumen that block thiamine (B1). B1 is essential for glucose metabolism and as nerves can only metabolise glucose (ie not fat) they suffer most and the animal is blind. I'm curious if the animals seen are actually blind and not just extremely slow due to the anaemia.
GM status is irrelvant.

Now I have to admit most of this went way over my head, so, if they stop eating it do they regain their sight ?
 

Buchan

Well-Known Member
Now I have to admit most of this went way over my head, so, if they stop eating it do they regain their sight ?
I've edited it - hope it helps. As to regain sight, if the poisoning is rapid and the deer remove themselves from the field, yes. However, a thiamine deficiency can lead to changes in the brain and it's irreversible.
 

morena

Well-Known Member
Useful reference Can J Comp Med Vet Science 1944 Feb 8(2) 38-41

Bear in mind that Roe Deer are browsers and obtain 40 % of intake directly from plant cell liquid contents, the majority of which passes directly through the omasum to the abomasum.The rest of intake, cell walls etc are digested in the rumen. Roe deer actually digest the proteins in the hind gut. (Hoffman et al).
I have also had a reported case of a Muntjac with OSR blindness where the stalker walked right up to the animal in a field of OSR and it was only aware of him when he waved his arms.
 

25 Sharps

Well-Known Member
I seem to recall from my DSC was that it was the type of rape that was being fed upon determined the extent of the illness, the type that was grown for slip lubricant rather than the food oils being the worst offender and that is not grown so much any more. Something along those lines anyway! I was concentrating more on dates and deer recognition. . . . Paul at Corinium took the course so he'd be able to tell you!


According to the introduction of the report below in 1987 there were reports of high wildlife mortality due to '00' rape and it think this may have since be replaced in favour of 'HEAR' rape more recently. . .
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjsidqDsZHPAhUDKMAKHZs6At8QFggcMAA&url=http%3A%2F%2Fbookshop.europa.eu%2Fmt%2Frapeseed-00-and-intoxication-of-wild-animals-pbCDNA11771%2Fdownloads%2FCD-NA-11-771-EN-C%2FCDNA11771ENC_001.pdf%3Bpgid%3Dy8dIS7GUWMdSR0EAlMEUUsWb0000rqWaiBd5%3Bsid%3DVuBnUJMRUOFna8BFzxz59_E0UTNhgzHSKrA%3D%3FFileName%3DCDNA11771ENC_001.pdf%26SKU%3DCDNA11771ENC_PDF%26CatalogueNumber%3DCD-NA-11-771-EN-C&usg=AFQjCNHmX-aO_-4h6I4S4I_IQ4UyW1Q-Gw&bvm=bv.132653024,d.ZGg
 

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