Poison in the Pasture – Pin Cherry

Wild Black Cherry (photo: Ohio Extension)

 

Both Wild Black Cherry and Pin Cherry trees are members of the rose family commonly found in Southern New Hampshire.  Pin Cherry is a common first-generation species after logging or forest fires create an opening (thus its alternate name, Fire Cherry) and is one of my chief concerns on our property.  We’ve cut several trees down from the margins of our primary pasture, but the back pasture that we’re restoring is positively full of them.

 

Pin Cherry

Cherry presents a poisoning hazard to all animals, particularly ruminants.  The hazard comes from cyanogenic precursor, prunasin, present especially in the leaves and bark.  When live, these precursors are not toxic, however when the plant dies the compounds break down, producing hydrocyanic acid (cyanide) which is highly toxic.  For this reason, fallen branches and wilted leaves are the most dangerous to livestock.  This hazard can be present in cherry-contaminated silage.  Once the leaves are allowed to dry, the cyanide is lost to the air.  Pin Cherry may contain less of these toxins than Black Cherry (reference). 

Back "pasture" is beyond the far fence... it's essentially a Pin Cherry orchard right now.

Cyanide blocks the body’s ability to use oxygen at the cellular level (the name derrives from cyan, referencing the blue tinge that can occur in tissue without oxygen-enriched hemoglobin).  In most animals, symptoms appear soon after ingestion and start with the body’s physiological response as it attempts to get more oxygen – rapid and labored breathing, anxiety, and stress.  If a fatal dose has been ingested, respiratory and/or cardiac arrest will normally occur within a few minutes to an hour.  First aid exists in the form of a cyanide antidote; however, as it must be given intravenously within a few minutes of the onset of symptoms, it is usually not an available and/or practical treatment (click here for a more extensive discussion on this from the Purdue extension office).

For that reason, prevention is the best cure for cherry poisoning.  We’ve been busy removing cherry trees from areas to which our livestock have access.  In addition, it’s a good idea to check the margins of fields/runouts/pastures after storms, frosts, and/or droughts to collect fallen, branches, and leaves before allowing livestock to graze.

On the plus side, these toxic compounds are concentrated in the leaves and bark, and the fruit itself is edible.  Black cherries can be sweet (watch out for the pit) for eating or processing.  Pin cherries, on the other hand, are quite sour and are best in a sweetened jam or to add tartness to sweet recipes.

Black Cherry wood is also prized for woodworking, though again, Pin Cherry falls short here.  Not only are large diameter specimens rare, but my woodworking friends tell me it is prone to splitting.  However, we’ve found several uses for the copious amounts of wood, and much of what is too small to be good for firewood is in a separate stack to be used for smoking meat next year.  In addition, we’ve been burning all the slash too small for either purpose to use for ash to bring down the acidity and bring up the potassium levels in our fields. 

MORE REFERENCES:

1. http://www.vet.purdue.edu/toxic/plant46.htm
2. http://plants.usda.gov/java/profile?symbol=PRPE2
3. http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/prunus/pensylvanica.htm
4. http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/prunus/serotina.htm