Natural Sequence Farming

[gbell]

Peter makes an assertion in his book Back from the Brink that most poisonous weeds lose their toxin after a few days of being slashed. Does anybody know if this applies to fireweed (ie. it would become edible to stock) and have a reference?

I'd like to scythe my overgrown paddocks, and feed the result to stock, but there's fireweed throughout...

Also, if used as a mulch will it takeover, or will the principle of increasing fertility with weeds-as-mulch cause it to be outcompeted?

I'm just wary that somewhere out here there's an inedible weed that will take over even fertile, undamaged soils...

Thanks,
Greg

[duane]

If that thought and principle WAS correct then that plant would by now have overtaken the Earth.

It has not happened and will not happen.

[Shirley Henderson]

I believe fireweed can be pretty dangerous if eaten. The fireweed is however toxic and stopping animals from choosing this area to eat. If you have overgrown paddocks it sounds a lot like the fireweed has been working and your land is repairing from clearing, fire or compaction at a guess. If you let the animals in to graze you will probably find they ignore the fireweed as it tastes terrible (the first warning sign). They can leave their manure behind to increase your fertility. You can watch to see if they eat it and if concerned move them out. Let us know how it goes. I have seen an area where I work repaired beggining with fireweed. Rabbits and wallabies graze there. Unless your stock are starving I doupt they will eat the fireweed. Also in regards to loosing it's toxins if slashed: Fireweed lasts longer than others when slashed as it has a survival technique of finishing off the seeding process before dying. The dying plant will force all of its energy into the seed head as a last ditch effort to ensure the next generation begins.
Shirley

[gbell]

Hi Shirley, thanks for your response.

[Shirley Henderson]

A danger of slashed or mulched fireweed is that it wilts and becomes more attractive to stock, which may increase the risk of livestock poisoning. After slashing or mulching, fireweed-infested paddocks should not be grazed for at least two weeks.

[Shirley Henderson]

Fireweed (Senicio madagascarensis)

Very common throughout SW Queensland.

Fireweed is responsible for many cases of poisoning resulting in ill-thrift in livestock. This is because it contains pyrrolizidine alkaloids that are toxic. These chemicals produce a characteristic type of liver damage. All growth stages and parts of the plant contain these chemicals. Hay or silage contaminated with fireweed can be toxic, as can stands of the plant that have dried off in summer.

There are three sets of circumstances where ingestion of fireweed by livestock is difficult to avoid:

* where there is a severe shortage of other feed (often in winter on the coast when fireweed is prolific) and fireweed is the only feed available.

* where the pasture is so heavily infested with young fireweed plants that they cannot be avoided by grazing livestock;

* where a paddock with a thick stand of fireweed is slashed and then grazed by stock immediately afterwards.

Cattle and horses are most susceptible to the toxic liver damage from fireweed. Young, hungry stock are in the highest risk category. Normally, cattle and horses avoid fireweed when adequate pasture is available but may eat the weed when the quality of pasture is low.

Sheep and goats readily eat fireweed. They find the plant highly palatable and often eat fireweed in preference to other plants. Paddocks that are grazed with sheep or goats are kept relatively free of fireweed.

Sheep and goats are 20 times more tolerant of pyrrolizidine alkaloids than are either cattle or horses. This is because they have a specific bacterium in their rumen that enables them to detoxify much of the alkaloids.

Although fireweed is much less toxic to sheep and goats, it can cause some liver damage in them if large quantities are eaten over long periods, e.g. consecutive seasons or years.

Pastures contaminated with fireweed should not be baled or made into silage. A program to remove the existing fireweed plants should be carried out prior to any hay making or silage operations.
Somewhere else on the web it was stated that the toxins can remain in baled hay for months.
Maybe it is best to use your slashed hay for mulch and to restore fertility to the soil instead of for feed.

Hope this was a little more helpful
Shirley