>> Most beef producers rely on harvested forage as a primary feed resource during
at least part of the winter feeding period and when dry weather during the
growing season reduces pasture growth. In this edition of Beef Tips, we're going to
focus on timing of hay harvest. I'm Dr. Ron Lemenager, Beef Extension
Specialist in the Department of Animal Science at Purdue University.
>> And I'm Dr. Keith Johnson. I am Purdue University's Forage extension specialist.
>> Keith, let's begin this discussion talking about when should we harvest a hay crop to both
optimize quality and quantity in a beef cattle enterprise.
>> Well, as I see it, grasses like tall fescue, orchard grass, and Timothy should be harvested for the
first time shortly after the grasses begin to head and before pollen shed
happens. Thereafter grasses will be harvested on about a six week interval.
Alfalfa, a common legume, should be cut when the flower buds are fully formed
and beginning to bloom. Red clover, another common legume, should be
harvested before a third of the flower heads are in bloom. Flower formation in
the spring at first harvest is not as good an indicator of when to harvest,
rather we should be looking at the presence of crown buds as a better
indicator. Grass legume mixtures should be complementary with one another. So we
look at alfalfa and red clover really working well in a combination with later
to mature orchard grass or a low endophyte or novel endophyte tall fescue
and harvest is dictated by the legume component of that mixture.
>> So Keith, what's your recommendations for proper harvest moisture content of different
types of hay packages.
>> Well certainly bale density and the size of bale
dictates the right targeted safe moisture level to begin baling. Small
square bales should be less than 20 percent moisture. Big round bales less
than 18 percent, and big square should be in the neighborhood of 16 or 17 percent
moisture. What happens with moisture above those levels is they promote
microorganism growth that can result in excessive heating
within the bale, and in storage the internal bail temperature should be less
than 125 degrees Fahrenheit. But higher temperatures should be carefully
monitored because high internal bale temperature can bind some of the protein
to fiber making some of it undigestible, produce molds which further
reduces the quality of the hay and then we can possibly look at fire being a
real concern with excessive heat. If harvested too dry, so we get down to less
than 15 percent moisture, we're gonna find that we can have extreme leaf loss
occur. And this is particularly an issue with legumes where the leaves are the
highest quality portion of the plant. I won't get into details today, but there
are moisture probes that can be purchased or procedures using forced heated air
small ovens, microwave ovens or vortex dryers made with a hairdryer that
can be used to determine hay moisture content >> You know Keith, unfortunately
mother nature plays a role in whether or not we can make a timely harvest of
hay. Let's talk a little bit about how weather can impact hay harvest and
ultimately hay quality and especially with that first cutting.
>> Well, certainly, mother nature does have many personalities, and one needs to make sure
that there are at least three consecutive predicted days of no rain to
make top quality hay. We do want to make hay when the sun does shine. One cannot
be successful in making quality hay only on the weekend. Delaying harvest beyond
the targeted plant stage does result in less protein. It results in more fiber,
and that excess fiber results in less digestibility and a lesser dry matter
intake by the consuming beef animal. Higher humidity does lengthen the time to dry
down to a safe baling moisture, and we want to make sure if possible that the
soil is not really wet because a wet soil is going to delay the dry down
process. And wheel tracks that can occur with wet soils can hurt plant crowns and
this affects the regrowth and productivity of the
next crop. Rained on hay and the swath or the wind leaches soluble nutrients
into the soil, and this is going to reduce digestibility. The extent of this
damage depends on how much rain falls, the number of days before sunshine
returns, and where the hay was in terms of its dry down moisture content when the rain fell.
>> You know Keith, you mentioned about this leaching and
that kind of thing, and there are times that you've watched
the weather forecast, you think you've got that three or four day
window to get dry hay. You're almost there. You're two or three hours away
from from that hay hitting your target moisture content. And the storm clouds
are brewing in the West, and you have to make the decision: am I going to
pull the trigger and am I gonna start baling hay when it's a little bit too
wet or do I go ahead and just wait it out and hope that the rain doesn't fall
too hard, too long and that the sunshine comes back soon? What do you do in that situation?
>> Well there are consequences that actually can happen if you do
harvest that hay and really what I would suggest happen is that we have a
propionic acid, acetic acid preservative applicator mounted on that baler and be
willing to invest in the cost of the preservative to keep the hay from
developing microorganisms that creates the heat and the molds.
>> In summary, the key take-home points are harvest at the correct stage of plant maturity to
optimize forage quality and baling at the correct moisture content to minimize
heating and storage losses.