Worm Wars

A number of years ago I was at a Crop Seminar on alternate methods for weed control.  I went there thinking that I would find some alternate pest management strategies such as rotation, permaculture, green manures etc.  Instead I listened to a lecture on tank mixes of various herbicides.  

Our use and in some cases overuse and abuse of chemical herbicides has resulted in a vast number of weed species that are resistant to these chemicals.  The response has been to bring out stronger and new chemicals and now tank mixes of a mixture of chemicals to combat weedy species.  

We have a number of invasive weeds here on the farm that are resitant to any number of chemical herbicides and we don't even try to go after them with these methods.  Now we are mowing before they go to seed, using competitive exclusion etc. Since we have seldom used herbicides on this farm it is unlikely that we created the resistance on site.  The resistant species have invaded on the wind or tagging along with wildlife or tires.

So what does this have to do with worms, that is internal parasites of our sheep and horses?  Like with weeds, over this summer we have found that the internal parasites in our sheep are resistant to two of the main products used to eliminate these parasites ie Valbazen and Ivomec.  The choices for alternate products here in Canada are very limited.  And are we alone?  No, a recent U. of Guelph study showed that about 80% of the farms they tested had some level of resistance to these products.

Are we at fault for the resistance problem on our farm?  Probably but no more so than any other shepherd trying to reduce the parasite burden within their flock.  Some resistance we probably imported from farms where we sourced animals and some was probably developed on this farm with our deworming practices.

With all our technology we just can't beat good old fashioned natural selection.  By using a drug that is lethal to the organism being controlled we have very strong selective pressure to organisms that are resistant to that drug.  With random mutations occuring in an organism all the time, some of these mutations will by chance confir resistance to the drug.  Put very strong selective pressure on that population of organisms and only the resistant  organisms survive.

The purists say that there are natural dewormers.  Maybe they work if the burden is low or work to prevent acquiring the organisms in the first place but as treatment for a serious burden in reality most do not work.  Been there, tried that, tested that.  Apple cider vinegar - doesn't work.  Diatomaceous earth - doesn't work.  Garlic- doesn't work.  Pumpkin seeds - doesn't work.  Willow leaves and black walnut leaves - might work to an extent.  Bird's foot trefoil in pasture - might work.  Elevated bypass protein- probably helps.  Rapid pasture rotation and long pasture rests between  grazing- probably works.  So the solution is not so much drugs but fencing and seeding.

Our ewe flock that is rotated through pastures with high concentrations of bird's foot trefoil, crown vetch and some willow are almost completely clear of parasites.

We have also been monitoring ewe and ram families and are selecting for resistant lines.  These unfortunately are not necessarily our most productive lines.  However heavy parasite burden reduces production so it is a trade off.

Are we out of the dark regarding parasite control?  No but we are working on strategies and testing those strategies. I do not think that it is a goal to be totally rid of parasites but to be able to co-exist with them without having an effect on production.

TTFN,
Laurie

Go with your gut and don't believe everything you see

We had a sick lamb the last few days and I was at a loss as to what to do to help her. Sure I could treat the symptoms but I wanted to know the cause.

This was a 5 month old market lamb. She was lethargic, obviously constipated, not urinating, uncomfortable, very slight elevation of temperature, not eating or drinking. All really serious signs. We treated her with bloat ease and when that did not work mineral oil. Even though she had just been dewormed, I went with my instinct and retreated her with a product for tapeworms. I also did a fecal test and there was nothing present.

Yesterday morning she still had not passed anything so I brought in the vet. He diagnosed a slight respiratory noise put her on LA tetracycline and vitamin supplement.

Fifteen minutes after the vet left she pooped and peed (obviously too soon to have anything to do with his treatment). She immediately started to eat and drink. And then that afternoon she started to pass huge numbers of tapeworms. She was obviously blocked with these parasites.

By evening she was bright, eating voraciously, drinking and very vocal in her protests of injustice of isolation.

If I had just gone with what I saw (ie nothing in the fecal test) or treating the symptoms, I might have a dead lamb on my hands.

Lesson for others. Tapeworms are not inoccuous. This is the second lamb in two years we have had blocked by this parasite. It is not just barberpole worms that can kill.

TTFN
Laurie

Fall is coming fast

Time is flying fast...just like the geese that are showing up in our pastures and the swallows that are starting to flock to migrate for the winter. The overnight temperature was in the single digits and it was definitely sweatshirt weather this morning. I better get my tomatoes harvested soon and hope there is time for my melons to ripen.

The lambs are growing well and field by field we are switching our pastures from "horse-safe" fencing to "sheep-safe" fencing and are establishing a system that will allow us to rotate pastures on a weekly basis. That and spot tile drainage and reseeding our pastures will really set us up well for next summer. We will be able to rely more on pasture for nutrition and less on hay and grains. We also will be able to improve our parasite control. As planned the sheep might be as long as two to three months before they return to the first pasture. Our cattle will rotate behind the sheep cleaning up the pasture before the sheep return.

We finally have harvested our first cut hay and have it under cover. The second cut will come in next month and like squirrels preparing for the winter, I will give a big sigh of relief.

Our two steers are doing well on pasture and have just been rotated into another field. Our horses will be moving onto their winter pasture soon and the summer pasture they are currently on will be reseeded.....it never ends.

Until later in the fall,

Laurie from Hawk Hill