Recently we shared a video about Kaos Sheep Outfit and how their sheep manage grass and weeds in vineyards. It’s an efficient and cost-effective way for vineyard managers to remove unwanted vegetation. But if the sheep eat the vines too, that could be a problem. One solution comes from Morgan Doran, whose Western SARE (Sustainable Agriculture Research and Education) funded project took research done at Utah State University and turned it into a procedure that sheep producers can safely use.
The technique that Doran and his team built on was based on research led by Dr. Fred Provenza. What Fred and his team (which included Beth Burritt, an On Pasture author) were looking at was how animals choose what to eat. They learned that animals prefer foods that give them good nutritional feedback, and they wanted to find out if animals would quit eating nutritious foods if they got negative feedback. They demonstrated that lambs acquired aversions to nutritious grains when they were given an oral dose of lithium chloride (LiCl) immediately after eating the grains. The aversion happens because LiCl causes a temporary stomach illness that animals then associate with whatever food they had just eaten. Their discoveries led to a new definition of palatability, where animals choose to eat foods not based on flavor, but on the nutrients that give them good feedback, or the toxins that give them bad feedback. (You can learn more about palatability here.)
Training Your Animals
While the process for training sheep to have an aversion is simple, the steps must be followed carefully so you get the result you want and you don’t accidentally overdose and kill your animals. The Fact Sheet “Vines and Ovines: Training a Food Aversion in Sheep” outlines the steps and the important precautions you must take. Make sure your animals have access to as much salt as they want since proper doses of LiCl are not normally lethal unless animals are deficient in sodium. The prescriptions for using novel foods (foods your sheep have never eaten before) and the proper dose of LiCl are very important. If you’re considering this, be sure to download both the Training Fact Sheet and the LiCl Dosage Fact Sheet and follow them carefully.
Here’s a video showing how the aversion worked in a demonstration at Utah State University:
Grazing Management is Still Important
In addition to creating a strong aversion to the vines and grape leaves, Doran and his team learned a few tricks for managing the sheep that improved their results. They discovered that by incorporating non-vineyard areas as part of the vineyard grazing blocks, the sheep seemed more comfortable, maybe because they could keep to their normal daily grazing habits.
Giving trained sheep another place to graze is important because it reduces the possibility that the sheep will taste a leaf or vine simply out of boredom. Since animals choose what to eat based on the feedback they get from nutrient and toxins in the food, sheep who eat grape leaves and vines and don’t get dosed immediately with LiCl will get only good feedback, and they will lose their aversion. Even worse, research shows that if other animals see their herd mates eating a food, even if they were trained not to eat it, they will again begin trying it, and the entire herd will lose their aversion.
If you’ve done this with your sheep and you have additional advice, do share in the comments below. We’d also love to hear from you if you’re considering doing this.