For the last couple of years, I have been trying to find information about the feeding of "juiced" or treated hay to sheep.  Wisconsin can be extremely wet and humid especially in the month of June and sometimes July when most of our hay is cut.  Sometimes it is a challenge to find enough dry days in a row to cut the hay and let it lie on the ground to dry.  If freshly cut hay is rained on, it is not a big deal (despite old wives tales to the contrary) since freshly cut hay is pretty wet anyway.  But you don't want nearly dry hay to be rained on. 

At best, it requires that the hay be flipped an additional time, which costs money (farmer time and diesel) and knocks leaves off the alfalfa which reduces protein content as well as yumminess to animals.  It also bleaches the hay out yellow -- which looks yucky so people don't want to buy it.  At the worst, if you get a bunch of days of rain in a row, it will just get musty and gross laying on the ground.  So if a big storm is moving in then you have to decide if you bale up the hay a little wetter (and risk mold) or let it lie there and risk it all being ruined from getting musty and gross. 

In Finland, it is quite common to treat hay and/or silage (which is hay with a higher percentage of moisture that is packed so that it gets hot and ferments which helps retard mold. They use lactic acid or muratic acid.  In Finland, they get one or maybe two cuts of hay a year, and the first cut in the best.  If I wanted to see amazed faces in Finland, all I had to say was, "We sell a lot of our first cut hay and keep the second cut because it is better."  <Shock and awe!> 

Their first cut is big and I have been told better.  In Finland, their growing season isn't long enough to always get a second cut of hay and I got the idea that it is rather sparse.  I don't know what the protein content is.  Some shepherds will cut and bale their hay field for one cut and then graze the sheep on it for the rest of the year because there is not enough growth to bother trying to cut / bale for hay.  They use a lot of silage or haylage which they call "wet hay" because they often do not have enough hot dry days in a row for adequate drying.

In the U.S., our first cut of hay (usually early June in southern Wisconsin) grows fast and has a high percentage of grass and less alfalfa.  There is a lot of it, like 3 times as much as second cut, but it is lower in protein.  The second cut (usually in mid to late July) grows slower because there is a lot less rain.  But because it is hotter and dryer outside, the grass goes somewhat dormant and the alfalfa flourishes.  Alfalfa (a relative of the clover plant with smaller leaves and purple flowers) has deep roots which can find the moisture deep in the dry soil.  (In July and August you may notice that all the grass in your yard looks dead but the clover is beautiful and green.)  In theory, our third cut of hay is even better except that in Wisconsin we don't usually get a third cut of hay since growing season is too short or we don't get enough hot/dry temps to dry it.  If we do get hay late in the year, some people turn it into silage since less drying is required.

We hire a farmer to do "custom hay work" for us since we only have about 12 acres of hay which isn't enough to justify buying the huge and expensive equipment required to cut / flip / bale hay.  A couple of years ago, he got a new baler to make large squares which are 3 feet by 3 feet and as long as as you want to make them.  This new baler has a tank on it for treating (or "juicing") the hay as it is baled with a product to retard mold.

Here is the haybine (a specialty tractor) that cuts our hay.  This was a third cut which is why it is so short.  The first and second cuts are usually about a foot high when the hay is cut.

When I talked to our neighbors (mostly hobby farms with horses) they had an extreme negative reaction and said that they would never feed it to their horses, though they didn't know if it would be bad for sheep or not.  But when I asked WHY it was bad, nobody could tell me a specific reason.  A few months ago, I emailed Dr. Dave Thomas, professor and head of the sheep department at the University of Wisconsin at Madison.  He said he knew of no problems with using it but referred me to Dr. Dan Undersander, also a professor at the University of Wisconsin at Madison who is a forage specialist.  Here are my notes from my conversation with him.  There doesn't seem to be a lot of info on this topic readily available on the web, so maybe it will help others as well.

Use of Propionic  Acid Treated Hay in Sheep

Phone Conversation with  Dr. Dan Undersander ,  Professor & Forage Specialist – UW Madison

June 7, 2010

Use of propionic acid in hay for sheep is not detrimental in any way.  Propionic acid is a substance that occurs naturally in the rumen of sheep and cattle.  So it is not considered a medication or anything unnatural.  A Canadian study in sheep showed that the sheep consumed hay treated with propionic acid at a greater rate than they did untreated hay.  (So there is no problem with palatability.)  He said that in his personal experience with cattle, they would always eat the propionic acid treated hay first before they would eat the untreated hay.  Propionic acid is often considered beneficial to sheep and is used to treat problems such as ketogenesis.

Moisture probes for hay should only be used for baled hay (not loose hay).  However their accuracy can be greatly affected by how densely packed the bales are.  Inaccuracy of 3 to 4% will make a difference in whether hay will mold or not.  Also, going to a shorter bale (like 3 x 3 x 3) vs. a longer bale (like 3 x 3 x 8) will help in drying, as all areas are within 18” of an edge.  Hay continues to cure after baling.  So if you can stack the hay loosely somewhere for a week to 10 days before packing it into the barn, it will help with drying.

It is important to put enough of the product on the hay to be sure it works.  (Follow package directions.)  For hay with 18% moisture, you would need to use 8# per ton of hay.  For hay with 16% moisture, you would need 5# per ton of hay.

There are several preparations such as one by Land O’Lakes and a few others.  All contain propionic acid, something to make it smell good to humans and water.

Propionic acid treated hay is also safe for horses.  In the past, horse people have had bad results due to feeding hay that was moldy despite the use of the propionic acid.  But any illness was still due to mold and not propionic acid itself.