Monday, January 7, 2013

Sheep Eating Weeds

Farmers are forever fighting weeds.  A group of Spanish researchers may have found a nifty answer that is what you might call a win/win.   

At the University of Barcelona sheep and goats have been trained, well, conditioned, to eat weeds while not eating the olive crop.  As an added bonus the animals drop fertilizer right there on the spot where it'll do the most good.

How do you get a goat to graze only on the plants you want him to? 

Conditioned Taste Aversion.  This is a natural ability animals posses that alerts them when they eat something that is bad for them.  The animal has an unpleasant reaction after eating the toxic thing.  Thus, he learns that eating this particular thing causes an uncomfortable sensation.  This mechanism helps the animal avoid ingesting things that are poisonous. 

Thus, a goat can be conditioned not to eat a crop food by letting the goat eat the crop food with a lithium chloride chaser.  This simulates the unpleasant reaction that toxic plants produce.  In other words, the animal feels awful and throws up.  So the goat learns that the crop plant makes him sick.  Therefore, when allowed to graze in the crop bed he eats everything except the crop.

The University of Barcelona group successfully treated some sheep and goats to taste aversion therapy using olive plants.  Surely, they can teach other grazing animals to avoid other crops too.  Is this a greenies dream?  Weed your crop beds, feed your farm animals, skip the nasty chemicals, add manure to the soil, all at once? 

Don't break out the environmentally responsible confetti yet.  Like most good news, there is accompanying bad news. The lab induced taste aversion only lasted, on average, four months.  After that, the sheep and goats ate the olive plants. 


  1. I think after the holidays we all need taste aversion therapy!

  2. My aunt and uncle had goats on their farm while they were growing the apple orchards in the early years. Apparently they were ornery animals.