The Accidental Smallholder Forum
Livestock => Sheep => Topic started by: trish.farm on August 04, 2016, 04:59:56 pm
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So if I slaughter and eat my own lamb within the withdrawal period on a combi wormer, is it going to kill me?? Withdrawal is 56 days, and I want to slaughter at 42 days post worming.
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Manufacturers state withdrawal periods for a reason. Why on earth would you want to eat something within it's withdrawal period?! Wait the extra 2 weeks or don't use a wormer with such a long withdrawal (#thinkahead).
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as to the question would it kill or not I would say its improbable, but wouldnt take the risk after all the withdrawal period is put there for a reason. Plus it could potentially have serious adverse effects. I wormed lambs and remembered I gave them a longlasting wormer which meant no slaughter for 9 wks, so I had to just wait. For animals you want to slaughter give them albex, as it lasts shorter and you can slaughter them once the withdrawal period is over, a bit over a wk. I presume you used something similar to dectomax? In which case you will have to wait. The instructions where put there for a reason, as animal products have not been tested for use on humans, so could pose a serious risk. Sorry for the lecture, hope I wasnt too harsh. Maybe next time set a date for when you would like them to go off and worm them according to that date, following the instructions on pack; I always wait a few days over the ending date anyway just to be on the safe side :)
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Oooh, controversial I know, but if I *really* couldn't wait the full time, I'd eat it (I wouldn't share with anybody else though).
In my simple head, wormer concentration will decay probably exponentially after administration. So, after 42 days (i.e. 75% of the withdrawal period), I'd expect less than 25% of the drug to be remaining, and certainly no more than that. Given the safety factors involved in these figures, I personally would probably take the risk if it was just the once. Your mileage may vary and I'm off to hide now before everybody flames me!
:sofa:
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As Womble says decreases in the drug concentration will likely follow exponential decay, driven by the terminal half life of the drug and preparation concerned. You can generally regard 5 half lives' worth of time as indicating full excretion.
However, it may well not be that simple as the drug may partition preferentially in to some tissues (although being a wormer you'd hope that would be the guts and organs rather than muscle tissue) and it may also have relevant metabolites that each have their own half lives and potentials for human toxicity.
Plus you said combi wormer, which infers that there is more than one active ingredient to do all this guesstimating with.
All this makes it hard to work out what the risk would be at any particular point in time before the withdrawal period is up.
Of course, if the drugs in question have human data you might be on better ground. Withdrawal periods aren't necessarily there because the substance is definitely harmful to humans, it may be because food regulations dictate there can't be more than certain amounts as we don't want to be inadvertently medicating the whole population eating that item.
The manufacturers are probably best placed to tell you what the issues are but expect them to be very cagey and definitely advise you against eating it whatever their data say.
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You will need to complete an FCI form for the abbatior, on which you will need to declare that none of the animals being slaughtered has had any treatments which are not withdrawal period expired.
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About 30 years ago I worked on developing a wormer intended for the third world (human medicine ). It would have been a great human medicine for the developing world if only it were safe for pregnant women. It is all very well putting not for pregnant women as a warning in the UK but not very helpful in Africa. The drug concerned was albendazole. As per previous comments withdrawal times are there for a reason. They are based on real data from real animal or human studies.
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Agree with the previous posters. However, I have seen all walks in the agricultural world and I have to believe that there are plenty of chemicals entering the food chain if its not in this country I bet tons of imported meat has been previously dosed up to the eyeballs. To believe that beef imported from parts of Africa or Poland has the same strict paperwork as the UK then its naive. Same could be said in chicken coming from anywhere in the world. Plenty of farmers have accidentally self medicated with wormers etc all to live to tell the tail.
In future do worm counts over chemical treatments - saves the money and the hastle.
Hence the reason why we concentrate on buying organic.
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That was a very informative reply Blacksheep :thumbsup:
Another point which occurred to me is how were the withdrawal times actually calculated? Did the research company use in vitro tissue culture or was the work done on live and dead whole animals? Were sheep or cattle used to establish withdrawal times? What was the size of the sample? Were measurements taken every day, or at larger intervals. Was the work done on just one or two breeds of sheep? I could imagine that metabolism would be quicker in a fast growing commercial lamb than in say a slow finishing Primitive.
Is the manufacturer hedging their bets and going for the worst case scenario, or averaging out all the results? How was the statistical analysis of the data carried out?
I think what trish.farm is looking for is to be able to work out what would be the risk for her eating the meat and what might the consequences be if she goes ahead.
I think it's a very pertinent question, of interest and relevance to us all.
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In future do worm counts over chemical treatments - saves the money and the hastle.
Not necessarily so. I worked out that with my small numbers, it was cheaper to worm than do a FEC count, especiallyif the worm count said I had to worm. Now, that wouldn't be the case if I had larger numbers of sheep and why, I guess, that SRUC do cheap worm counts for crofters.
I'd like to see that extended to smallholders too and have raised it with ScotGov.
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Thought I had better explain as you now all think I am a total numpty who doesn't "think ahead" or plan her worming/slaughter dates!!!
I have NEVER had to worm any of my lambs in all the years of having sheep. I have enough grazing over the farm to move them every 3 weeks onto fresh ground. They are 6 months old, been weaned for 6 weeks and some are almost ready to go. And when I say I have never wormed, all their livers have been as clean as a whistle on slaughter and I have never had scouring.
My ewes and ram get wormed with the correct wormer at the correct time.
Last week my lambs started scouring, popped a poo sample to vets and was told to worm for everything including fluke.
The weather this year in our area has been a major problem for stock keeping and has caused massive worm counts.
Wormed them all according and they have already started drying up and are on yet another fresh piece of ground.
I home slaughter 4 lambs for my own freezer, the rest go away.
I have one entire ram lamb whose balls didn't drop, who I want to get done early before he starts to take an interest in his sisters/cousins! He and 3 others were going in my freezer early sept, before I have my annual break late in September, then the others will go in oct.
I was just trying to get the ram lamb away, without having to separate and make another small flock to make more work for the house sitter/animal carer.
Very simple, just wanting to make life easier and interested to know if by doing this I might make myself and my family ill!! Doesn't make me an idiot, or unable to plan my worming programme. Just the normal things that crop up on a with livestock to challenge you.
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Thanks for that [member=36832]trish.farm[/member] I wasnt saying that you were an idiot I was putting my point out there, I am sorry if I offended you, I truly did not mean to :'( The truth is I am thinking of your health in this. Animal wormers could pose a big risk of damage to your health, plus the meat might taste not good if the wormer is still in there. It would be better all round saving them for slaughter for later, I know that you do need them gone sooner, but in this case waiting would be better. Hope this isnt too harsh :)
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I completely understand your dilemma, but I just don't think it's worth the risk.
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I'd have been annoyed at my vet if he told me to treat for fluke unless he definitely saw fluke eggs in the FEC. Especially since you say you've never had any fluke before. If you don't have a fluke problem you probably aren't suddenly going to have one overnight, even in this wet weather.
I'm guessing you used Combinex? (thats the only combi wormer i can think of with 56 day on it) So that's Levamisole and Triclabenazole. I'd google them and see what their toxicity to humans is, from what I see both have been used in humans for various things but neither sound very nice, esp Levamisole.
As for worming being a cheaper option than FECs - do the FEC yourself. Over the long term it will be cheaper. It's not rocket science, you just need a microscope (cheap) and some slides. Most microscopes now have a usb conection so you can view on a computer screen so never need to peer down the periscope :) . [member=35918]Me[/member] is offering training on the marketplace at the mo, and there are docs on the web to show you what to look for. [member=35918]Me[/member] ... maybe there is a market here for a wee pamphlet giving instructions to smallholders (for a small fee) ;).
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As for worming being a cheaper option than FECs - do the FEC yourself. ;) .
Yeah, I kind of subscribe to "every man to his trade" in these important things. An influx of "enthusiastic amateurs" might not be the best thing in the long run.
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As for worming being a cheaper option than FECs - do the FEC yourself. ;) .
Yeah, I kind of subscribe to "every man to his trade" in these important things. An influx of "enthusiastic amateurs" might not be the best thing in the long run.
I disagree, I think this is the only cost effective option in the long run. Many farmers now do them themselves, and vets are advocating owners do them themselves. You can always split your sample and send half off and do half and compare the results, to check that you are getting the same results.
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I don't wish to be rude to anyone but these label claims of drugs are very highly researched to stringent protocols. Black Sheep indicates some of the complexity involved. After teams of scientists have spent many years doing all the studies, animal tissue, in vivo studies, often human too, the data goes to independent government (currently EU) scientific audit and the label claims are agreed. Trying to reverse engineer this by reading a few papers is dangerous. I have spent over 30 years doing pharmaceutical R&D setting shelf life's and being involved in protocols like this and I will admit to taking the odd risk based decision but it is probably not wise to do so based on forum debate with the usual mixture of fact and guess work. Clearly it is not 'dangerous' the day before then end of the withdrawal period or 'safe' the day after but that, and the label claim are the only facts you have. The rest is guess work.
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I don't wish to be rude to anyone but these label claims of drugs are very highly researched to stringent protocols. Black Sheep indicates some of the complexity involved. After teams of scientists have spent many years doing all the studies, animal tissue, in vivo studies, often human too, the data goes to independent government (currently EU) scientific audit and the label claims are agreed. Trying to reverse engineer this by reading a few papers is dangerous. I have spent over 30 years doing pharmaceutical R&D setting shelf life's and being involved in protocols like this and I will admit to taking the odd risk based decision but it is probably not wise to do so based on forum debate with the usual mixture of fact and guess work. Clearly it is not 'dangerous' the day before then end of the withdrawal period or 'safe' the day after but that, and the label claim are the only facts you have. The rest is guess work.
That will be me, then.
I don't take what you have said as rude at all. The info you have given is just what I was fishing for - someone who knows how the research is carried out and can pass on knowledge based fact, as opposed to kneejerk opinion.
So thanks :thumbsup:
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There was nothing wrong with what you wrote Fleecewife, it was well considered as always, and nothing wrong with checking out a few papers to get better informed either. As you appreciated I was just heading off anyone inclined to take the 'bit of knowledge' route. After years in labs and with science papers I really appreciate the hands on experience you and others add to the mix.
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OK, so the real question is, if Trish invites you round for dinner in a few weeks time (let's ignore the legislative complications for a minute), are you going to tell her you're vegetarian or not?
Good debate folks - really interesting :thumbsup:.
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Depends if she sprays her carrots just before she pulls them!
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...... or fertilized them with sheep poo!
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You ve got them to this stage, I think waiting a little longer, adhering to withdrawels,is a small price to pay when it comes to your health :hug:
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alternatively if you like [member=36832]trish.farm[/member] You could buy some ram lambs off me which are almost ready to be slaughtered and slaughter them instead?.... :innocent:
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alternatively if you like [member=36832]trish.farm[/member] You could buy some ram lambs off me which are almost ready to be slaughtered and slaughter them instead?.... :innocent:
...or me ;)
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That was a very informative reply Blacksheep :thumbsup:
Thanks :)
Another point which occurred to me is how were the withdrawal times actually calculated? Did the research company use in vitro tissue culture or was the work done on live and dead whole animals? Were sheep or cattle used to establish withdrawal times? What was the size of the sample? Were measurements taken every day, or at larger intervals. Was the work done on just one or two breeds of sheep? I could imagine that metabolism would be quicker in a fast growing commercial lamb than in say a slow finishing Primitive.
My pharmaceutical expertise is much more at the other end of the process :) Pharnorth knows this far better and has added to the discussion already. But potentially any and all of what you say above. As an illustration though, metabolism isn't one fixed thing where all processes run at the same rate and are all faster/slower - it's massively complex and hard to predict in some cases. A slow finishing animal may well have a faster metabolism too - burning more energy and thus gaining less weight from the food consumed. But that doesn't necessarily mean it breaks down drugs faster.
We humans have a range of generic variations in things like liver enzyme activity - a good example is in relation to codeine. Some humans lack the enzyme necessary to break it down and since it is only really when our bodies break it down to morphine that it provides pain relief they find the drug completely ineffective. Most of us have the enzyme and it works but again a small proportion are what are termed ultra-fast metabolisers and they turn the codeine into morphine so quickly that the levels generated spike high and fast, leading to side effects and sometimes toxicity. I have no doubt that livestock will have these sorts of variations too, the effects of which could have been magnified in the purified breeds we have developed, or within some flocks - and there'll be no real way of knowing.
Is the manufacturer hedging their bets and going for the worst case scenario, or averaging out all the results? How was the statistical analysis of the data carried out?
Hard to know without looking at the data in its entirety (which probably isn't available to us without detailed discussions with the manufacturer). However simply on the grounds of what is economically feasible I can't see that they will have performed formal testing in representative samples of every sheep breed, for example. So yes there will certainly be averaging and the addition of some degree of safety margin to allow for the variation described above.
I think what trish.farm is looking for is to be able to work out what would be the risk for her eating the meat and what might the consequences be if she goes ahead.
Yep, and we do estimations like this in humans regularly, for example trying to estimate what foetal exposure there may have been to a drug the mother used before she knew she was pregnant. But it is really difficult to do and impossible to be completely accurate about, even when the specialist knowledge is brought to bear.
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You will need to complete an FCI form for the abbatior, on which you will need to declare that none of the animals being slaughtered has had any treatments which are not withdrawal period expired.
Plus testing is carried out on meats to check for residues that shouldn't be there. The testing I believe is random but someone I know did have their lambs tested.
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I agree with all your points Black Sheep. The withdrawal dates are set on 'reasonable case' rather than 'worse case' and allow for as much as possible of the variation you mention. There is a dilemma in doing the studies that you need to reduce variation to understand in the first case how the drug is metabolised (how long it stays in the body and where) e.g. Using one or two breeds. But ultimately need to extrapolate that data to allow for all sorts of variations you haven't tested. So at some point science and data revue ends, i.e there is not enough money to test every variation, and compliance starts I.e if it says 56 days that is what the law expects as it is the best researched guess at what is safe. Consequently it is impossible to answer the original question scientifically, it can only be answered as a compliance question.
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thank you everyone, wasn't expecting quite the debate and such informative response, very grateful! I will take the words of caution and wait till after the 56 days. Ram lamb will be split up from the girlies in the flock and they will all enjoy a few more weeks of eating my grass!! Many thanks for so many interesting points.
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I don't even know if this is possible in sheep but you could ask your vet if it's possible to chemically castrate him for a few weeks over your holiday and then let him get that out of his system before slaughter - shouldn't take long.
I'm also a bit surprised you were told to fluke dose, were there any physical symptoms?
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What a fantastic thread and discussion. How lucky we TASers are to have such well informed and articulate experts at our fingertips.