venison vs brodifacoum

I've been researching this topic the last few days. The situation seems to be that commercial guys cannot harvest venison within 3 years/6km of brodifacoum application, and recreational hunters are recommended to follow the same rules (but farmed animals in the same areas have no withholding period). OTOH, MPI says there has been no recorded illness attributable to eating venison with brodi residues, and that the toxin accumulates mostly in the liver. Pigs are a different story of course with the potential for secondary poisoning from eating dead animals. For deer, the animals need to access the brodi directly. Brodifacoum is legally required to be used in bait stations, which are designed to limit or prevent non-target access to bait, so deer access to brodi is limited to what they can reach in bait stations, and any spillage. A good sized deer would need to eat almost 50kg of a bait such as 'pestoff' to reach the LD50 dosage, or in other words the total contents of 100 sentry bait stations filled to maximum capacity.

Every farm in my region is legally obliged to maintain possum numbers. Essentially this means every farm in this 26,000ha unit has brodifacoum and/or cyanide baits constantly. It works btw, I've only seen about 2 possums in the last decade, down from shooting 20-30 every night shooting back in the 80's.

I'm keeping all my bait stations filled but would only be going through maybe a bag of brodi (25kg) per year, and most of this is being buried untouched after it has gone stale. I don't know what the neighbours are doing, but presumably they are following the rules and using approved bait stations, out of reach of livestock. I've seen up to 12 deer at a time here (requiring 600kg of brodi bait to reach the LD50 rate). So it seems unlikely that any animal would be so toxic that it should be avoided completely.

So what is the consensus of feeling out there about taking some venison from feral deer in this situation?

There used to be a dedicated govt dept called The NZ Food Safety Authority. That authority set the safety boundaries for poisins like brodi and 1080 etc. They were absorbed into the EPA at about the same time as ERMA. The EPA and its HSNO branch will be able to give you full compliance details.
One other point: The LD50 is the dose rate which will on average kill 50% of the affected population. Bear in mind that a vulnerable person, child, fawn, bird, calf or insect, or you, my be the LD 10 or the LD1. There is no telling. Brodi is cumulative so a number of low doses add up.
Further, based on my research, the meat works and expirters do not as of normal actually routinely test for brodi unless specifically notified of a present risk. Sooner or later the customer in europe,asia or elsewhere will test and find contamination. What of NZ agricultural export industry then. Brodi enters milk too.
I am aware of bait station being knocked over by stock and of a contaminated shipment of mutton which got through before MaF woke up, then did zilch.
The risk to our ag producers is latent, suppressed and looms ever larger.

Deer must be far less susceptible to brodi than other mammals. I know it knocks pig's over pretty good.
The thing that makes brodi so effective is that it is a chronic toxin. Pests eat it and feel now immediate I'll effects so they eat some more. This means they won't develop bait shyness. This makes it really good for erradication projects. Cyanide is at the other extreme. It is an acute poison. This means pests die immediately but if they receive a sub lethal dose they will develop bait shyness. 1080 is in between.
If it wasn't for the bioaccumulation, brodi would be a great toxin. Just don't eat pig livers. ��

So would you guys eat venison from here or not?

Probably all good. I'd rather not know though.����

I suspect that it would be a similar situation to other cumulative poisons and toxins, heavy metals etc - where the older animals carry the highest levels.
A test that I would apply is to shoot any sick or poor looking animals and examine them for symptoms. If you are suspicious send a liver sample to Cawthron or similar and have it tested.
If all the deer in your area are bursting with health and fat, I would be confident that they are fine - just eat spikers and yearlings

What sort of bait medium is used? Palatable for deer?

My pig spot had brodi on it so I will wait til March next year. But I am not sure what I'd do then. They eat rats so I can't tell about secondary poisoning.

If its recent poison then check the poo. If it's the same or similar colour to the bait then you can tell its eaten stuff. My pig was normal but I chucked it anyway.

Im in a similar situation to you Ben, there are bait stations allover this country. Talking to the contractor this year they have an average of 1 bait station every 4 hectares in the area.
The monitor trapping for the last 2 years has only returned 5 possums so evidently it's working down.
I am happy to eat venison from the area, as you point out the quantity required to reach ld50 is impratically high and it's not an everyday meat.
I have always been fascinated by the "restriction" on game meat from these control areas entering the commercial food chain versus farmed protein, animal access to bait stations and their contents is basically the same.

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Originally Posted by Ben Waimata

So would you guys eat venison from here or not?

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No way.

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Originally Posted by Russian 22.

What sort of bait medium is used? Palatable for deer?

My pig spot had brodi on it so I will wait til March next year. But I am not sure what I'd do then. They eat rats so I can't tell about secondary poisoning.

If its recent poison then check the poo. If it's the same or similar colour to the bait then you can tell its eaten stuff. My pig was normal but I chucked it anyway.

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The blue dye is supposed to repel non target species, but I doubt anyone believes that. Any bait eaten by deer will be out of curiosity, they seem happy enough eating the clover and lucerne in my hay paddocks and chewing on my newly planted tree seedlings for some fibre!

Deer will only access brodi themselves, so less risk I hope. I would not eat pigs from around here, you'd need to assume much of their protein source would be coming from dead possums, rats and mice... possibly all dead due to brodfacoum. Some guys use brodi in bait stations with a layer of ferafeed on the top which protects it indefinitely, something I've just started doing. This means unless the bait stations are removed (illegal here) you can assume any pig is toxic.

Just because the ld50 is quite high it doesnt mean lower levels are not harmfull.
Has any testing been done in humans?
low level poisoning in us can result in all sorts of undesirable things without actually killing us directly.
If it is in the liver then how much is in the other organs and flesh?

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Originally Posted by Ben Waimata

The blue dye is supposed to repel non target species, but I doubt anyone believes that. Any bait eaten by deer will be out of curiosity, they seem happy enough eating the clover and lucerne in my hay paddocks and chewing on my newly planted tree seedlings for some fibre!

Deer will only access brodi themselves, so less risk I hope. I would not eat pigs from around here, you'd need to assume much of their protein source would be coming from dead possums, rats and mice... possibly all dead due to brodfacoum. Some guys use brodi in bait stations with a layer of ferafeed on the top which protects it indefinitely, something I've just started doing. This means unless the bait stations are removed (illegal here) you can assume any pig is toxic.

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No deer at my pig spot sadly.

I am going to shoot one in march and see what the insides are like. Probably going to err on the side of caution and not eat them for a while.

i would eat the deer if it was me, not pigs thou.

Hey guys. The restrictions on taking animsls for consumption are there for sound health and safety reasons. It is not a risk to be trifled with. It is POISON.

How much does a test cost ? A multi residue test used to cost $400 from Cawthron Institute. A multi is not needed in this case so a test for Brodi might well be less. Ask Cawthron if there have ever been any positive brodi results from deer linked to bait stations.

From my understanding there are quite a few people that want brodi to be a controlled substance and rightfully so and there are serious talks about that happening. One of the worst residual poisons out there, sediment testing in many estuaries and such places has shown up with brodi along with a couple of other residual toxins mostly found in rat bait.
There is a reason why DoC and several of the largest forestry companies in NZ have banned it.
The system appears to be rather two faced. A deer can not be taken by WARO or for pet food from an area within 2km of where brodi has been used in the past 3 years but it could be trapped or mustered in and sold to the works for consumption.
The scary thing is it is one rule for wild animals and another rule for farmed livestock so if an importer catches hold of it and drops their lip then a few farmers might find it is harder to get rid of their stock.
Someone queried above if it is palatable to deer, certainly is. A sweet cinnamon flavored cereal bait or I think you can get it in raspberry too. There is the odd interesting story around about deer being observed knocking philproof bait stations with their hooves trying to get the bait out to eat. That said most of the farms around Hawkes Bay have predominantly sentry bait stations and I personally wouldn't be too worried about eating deer from these areas even straight after the toxin has been used.
As for cutting animals open to see what they are like out of a poisoned area, I would say unless it has had a fairly high dose you won't see anything, it is an anticoagulant.
Suspected poisoning from brodi in dogs cats etc the vet just usually makes them vomit and gives them vitamin k.

I read up on some of the residue test results done on deer. Basically in one case 11 of 33 deer tested had trace levels in liver tissue. In another case none of the shot deer had any trace.
The levels were very low, so low that if we were to eat the deer our bodies poison elimination rate would be greater than the rate it could accumulate.
To put it in perspective, many people take Warfarin another anticoagulant coumarin poison.
Brodi is highly lipophilic, meaning it bonds to lipids ( fats ) so simple answer trim the fat off and throw the liver away and eat good healthy young deer taken at a time of year that there is plenty of feed around - now