One aspect of raising livestock and the danger that is present and yet often overlooked is the potential for plant poisoning. No matter what region of the country you live in there is a distinct possibility there are some plants in your area that are toxic to livestock, including goats. As a species goats, due to their selective style of foraging, arenít as susceptible as some other livestock species to plant poisoning. Usually it is only in a forced grazing situation that goats will consume toxic forages and wind up sick or in the worst-case scenario, dead.
Forced grazing on toxic plants can occur due to various causes such as over-grazed pastures in which only the less palatable/toxic brush and weed species are present, which is a common occurrence. This is one of the easiest situations to avoid by making sure your animals have ample, good quality forage available at all times. Another example of forced grazing may occur during times of drought when despite acceptable stocking rates, rainfall hasnít occurred in sufficient amounts to effect re-growth of preferred plant species. This is a situation that as a producer in a more arid area of the U.S. I am well familiar with. This past April, after six months with only two inches of rain having fallen, the point was driven home and in a dramatic manner I might add. The dramatic loss of livestock on Central Texas ranches, including mine, provided the catalyst for this article. Cattle, sheep and goats were all affected and in some isolated cases the mortality rate hit right at the 10% mark, an economic disaster to put it mildly!
When you get into this position there are really only two options available to you as a producer. You can feed in the pasture with sufficient quantities of hay and other supplements to meet the animalís nutritional needs, or put them in a pen and do the same. Either way you go it will be an expensive proposition with pen or confinement feeding being the most effective of the two. I suppose there is a third option of selling out and de-stocking until sufficient rain falls to effect forage re-growth, but if you have invested much time in a focused breeding and genetic improvement program this isnít a truly viable option. The loss of valuable genetic lines that have been developed by focused breeding arenít easily, if ever, able to be replaced. Then again we have to put the pencil to the paper and compare animal value to projected feeding costs and make your decision.
The bright side in my case was that the period during which the heaviest loss took place lasted only three weeks, after which the plant in question reached a later stage of growth, which rendered it less palatable and therefore the loss of stock dropped off. So, I didnít de-stock, but instead chose to feed in the pasture during this three-week ďtrain wreckĒ period and felt it better to leave the goats where they were. A friend of mine who was in the same situation chose the route of penning their nannies at the risk of losing their kids instead of losing both mother and kid(s). Then there is another friend who left their goats where they were and didnít go into a heavy supplementation program.
So which one of us did the right thing? You know that is something the three of us will probably discuss among ourselves and try to draw a conclusion about in the upcoming months. Right now we just arenít sure.
Another form of forced grazing, which can on occasion occur when we think we are doing the right thing, is feeding hay that contains toxins or toxic plant material. Most operations regardless of size will have times when they feed some hay for one reason or another, however haying is more common in smaller operations. There may be herbicide or insecticide residue present in bought hay and unfortunately until symptoms of poisoning appears the livestock owner is in the dark. The same can be said of hay that is baled out of a field infested with toxic plants, with the exception that plant material is more readily visible, so in this scenario there is a chance to see what is there.
As mentioned earlier goats will normally avoid toxins, but in a situation where hay is supplied as a regular feed-stuff, and no other roughage is available then they are being force fed the hay as well as all it contains, good as well as bad. Buying from a reputable source is good insurance but not always a solid guarantee of quality. If you have the opportunity to know the farmer growing your hay and can inspect the field prior to it being baled, do so. This would also be the time to visit with the farmer about his chemical application schedule as to the last time herbicides or pesticides were ďput downĒ on the forage. Inspecting the field will also let you see if there are undesirable or toxic plants present. It is a lot easier to see them standing than when theyíve been baled.
Another type of toxicity that can occur in normally safe forages is nitrite poisoning. Nitrates can accumulate to dangerous levels when certain plants are subjected to stress due to adverse growing conditions. A short list of some, but not all, forage plants that commonly accumulate dangerous levels of nitrates are small grains, corn, sorghums, as well as many common weeds, such as pigweed. Nitrates themselves arenít dangerous to livestock, but when converted to nitrites in the rumen they become ten times more toxic than the original nitrate itself. Nitrates accumulate in the lower parts of a plantís stem. As an example, grazed off sorghum that is drought stressed and then experiences a burst of re-growth due to rainfall causes the plant to pull up and carry a heavy concentration. Frost in the fall on Johnson grass can create a similar type of nitrate accumulation often in dangerous levels. Simple management can be used to avoid nitrite poisoning by avoiding grazing these various forages during certain times of the year, so if this is what you have to work with, donít despair.
Then we get to another cause of plant poisoning in goat herds; feeding yard material such as grass clippings and trimmings off of shrubs and hedges. There are quite a few highly toxic ornamental plants used for landscaping, many of which only require very small amounts to be fatal to goats. Oleander is quite probably one of the worst in terms of toxicity with as little as 0.005% of an animalís body weight proving fatal at times. Sometimes well intentioned visitors may pick a branch of greenery and offer it to your goats as a treat, not knowing what they have in their hands is highly toxic. Three other offending plants commonly used in landscaping are yew, rhododendron, and lantana; and the list goes on and on.
How many plant species there are across the U.S. that are always toxic to livestock I canít even guess, and then there are those who become toxic only when certain conditions are present, along with various molds and forages species. Lots of stuff to consider and I would recommend visiting with your local agricultural extension service personnel to find out what problems are likely to present themselves in your home area. As was mentioned at the start though the bright side is that unless forced to feed on them, most livestock species, including goats, will avoid consuming toxic plants. This article touches on, but certainly doesnít cover all you need to know about toxic plants, but hopefully it will be of assistance in your management decisions.