University of Illinois Extension

PorkNet Ask an Expert

Q. Is it safe for pigs to eat acorns? I have found lots of information on acorns being toxic to cows, but none on pigs. Our pigs are Yorkshire/Hampshire mix.
A. Like you, I have found much information on acorn toxicity in cattle, but I have never heard of a documented case of acorn toxicity in pigs.
Information on acorn toxicity in cattle from the following web page:
http://www.caf.wvu.edu/~Forage/acorns/acorns.htm)
states, "The poison in acorns (tannins) concentrates in milk; therefore, fast-growing calves (400-700 lb calves) on heavy-milking dams will be the first animals to show signs. Older cattle will rarely show signs of oak toxicity."
Knowing that feral (wild) hogs roam the woods, I am sure that they consume many acorns. Whether or not the tannins from the acorns concentrate in the milk of pregnant feral sows resulting in toxicity to nursing piglets, I do not know. We also know that a hog (a non-ruminant or simple stomached animal) can tolerate a higher level of some toxins than can ruminants.
So, you can see I am hedging on my answer to your question, "Is it safe for pigs to eat acorns?" Because I just do not know whether or not it is or is not safe for pigs to eat acorns.

I take the following information from the web site, http://www.holoweb.com/cannon/redoak.htm
This discussion refers primarily to cattle, the species most often affected by oak toxicosis. It also seems that cattle less than 2 years of age succumb to oak toxicosis more than do older animals, however older animals are still at risk. Other species at risk include sheep and possibly deer. Goats and swine are more resistant to poisoning, and horses are rarely affected (likely due to a unwillingness to consume oak). Pets rarely consume sufficient quantities to do harm. Many species of oak have been implicated in the poisoning of livestock, with red and black oak exhibiting greater toxicity than white oak.
While short-term acute poisoning by oak has been reported, the most commonly encountered oak poisoning is of a chronic nature. Oak is most dangerous early in the spring when the leaves and buds are the highest in toxicity and when there is little else to eat. The fall is another at risk period, when acorns and leaves fall and better forage dies back. Therefore, management plays a key role in preventing oak toxicosis.
The toxins in oak are called gallotoxins and are converted in the body to tannic acid, gallic acid and pyrogallol, all of which are very toxic to the kidney. It is the resulting kidney failure that causes the clinical signs. Typically, a significant amount of oak needs to be consumed over a period of time before clinical signs appear. Signs can develop over 2 to 14 days, or signs may be present with the animals becoming progressively worse over many weeks. The number of animals affected in the herd can vary greatly, but of those showing clinical signs, up to 80% may die. Signs of oak poisoning can include depression, lack of appetite, a gaunt and emaciated appearance, poor or rough hair coat, dependent edema (fluid buildup under the skin under the neck, abdomen or on the legs), digestive disturbances (both diarrhea and constipation have been reported, with mucus covered or tarry stools), increased drinking, passage of copious amounts of urine which may contain blood, and death.
FIRST AID: The most important step is to get the animals back on to plentiful and nutritious feed, and to limit stress, shipping and handling during the recovery period. Also, make sure that plenty of fresh water is always available, since affected cattle cannot maintain their own water balance very well while recovering. Since this is a long-term chronic toxicity, there is little in the way of an antidote to relieve signs. Severely or more chronically affected animals may not recover, but the less affected animals may, and may return to previous rates of gain and milk production. A veterinarian will be able to assist in management, and will be able to assist in emergency measures if large amounts of oak were recently consumed. Beyond this, treatment is supportive and symptomatic.


Sincerely,
Gilbert Hollis
Extension Swine Specialist
Department of Aninmal Sciences
University of Illinois Extension