Re: Re: Haylage/Silage

["Kim Pelletier" <kim@redhorsetech.com>]

Duncan Fletcher wrote:

> According to NRC optimum pH is a bit lower (3.5 to 4.5). Silage is not
> generally controlled well enough and a number of cases of botulism have
> occured feeding silage.


Scary stuff (botulism), huh?  --- I've found that there have been reported
cases of botulism in horses fed haylage as well.  Young, growing plants
standing in the field are usually not the best "medium" for this bacterium,
but the dead critters that may have been raked in with the grass crop are
usually the culprit.

The pH of 5 for haylage was quoted to me by a Canadian ag specialist a year
or so ago... perhaps their environment (colder temps, etc.) does not allow
for a more optimal fermentation, which would keep the pH towards the upper
end?  They don't seem to have a problem making good beer though, LOL!



> >From a nutrition standpoint, haylage will have somewhat higher values for
> most nutrients but significantly lower vitamin D which actually increases
> substantially during sun drying.


Definitely agree.  The energy and protein values are usually higher in
haylage since the plant was harvested while young, resulting in more "bang
for yer buck" on these nutrients pound for pound on a dry matter basis.

BTW, thanks for the remind on vitamin D :-).  Only in dead/dying leaves or
cut, sun-exposed plants will you find more of the plant's ergosterol
converted into vitamin D2 (chlorophyll blocks a good amount of vitamin D2
synthesis in the plant).  When the plants are young, green, and then
processed into haylage, there are usually very few dead or dying leaves on
each young plant.  In addition, haylage is not exposed to sunlight during
the fermentation process.

For endurance horses, this shouldn't be a problem since most are exposed to
the sun's UV radiation sometime during the day, and many are fed sun-cured
feeds on top of that.  However,  I could see a vitamin D deficiency being a
concern for those horses kept in a box all day, everyday... fed haylage or
other feeds not sun-cured in the field, and turned out only at night on
drylot to prevent their coat from changing color due to sun exposure.
Otherwise, I understand that it is difficult to create a vitamin D
deficiency in horses kept under somewhat normal management practices.  Being
a fat-soluble vitamin, most horses can even get through a dreary, dismal
winter easily with very little sun exposure and pasture until spring.

Vitamin D toxicity from oversupplementation by a well-intentioned horse
owner is another can of worms altogether, since the symptoms of a deficiency
and toxicity are very similar.

Well, have a good weekend!  Get plenty of sun :-)!


Kim  (and Lee, getting plenty of exposure to sunlight and lots of sun-cured
hay  :-)  )

Lubbock, Texas