Whether the forage sorghum becomes hay
or silage, is used in a summer grazing program, or as an
alternative crop, interest is definitely picking up, said Dr.
Brent Bean, Extension agronomist, and Dr. Ted McCollum,
Extension beef cattle specialist.
Seed dealers attending the annual Forage
Sorghum Variety Trial Field Day said they are seeing large
increases in sales due to dairies and feedyards growing
acceptance of forage sorghum silage, according to Bean.
This year's trial at the Bush Farm
included more than 90 entries, comparing a wide variety of
sorghums, such as: brown midrib, photoperiod sensitive, forage
sorghum, grain sorghum, sorghum/sudangrass, sudangrass and even
some sweet sorghums aimed at the bioenergy market, Bean said.
Each type of sorghum has its strong
points, he said. The brown midrib varieties on average produce
higher quality silage, and the non-brown midrib varieties
typically produce a higher yield.
The photo-period sensitive varieties can
produce very high yields if a one-time cutting is used, or can
be harvested 60 to 70 days after planting for a haylage crop and
then cut again 45 days later, he said. In this system, a
producer can still plant wheat after the second cutting.
Several varieties identified in the
Experiment Station trials produce a consistent high yield along
with quality similar to corn silage, Bean said. These varieties
are now being labeled with a tag from the National Sorghum
Producers.
The National Sorghum Producers cited
changes in silage sorghum genetics and the continued research
and development of high quality forages when it launched a
branding program aimed at helping producers make seed selection
decisions.
In another area, producers are taking a
second look at sorghum-sudangrass for their summer stocker
grazing programs, McCollum said.
Studies in the first five years have
shown the brown midrib sorghum sudangrass was more digestible
and produced higher daily gains than the photo-period sensitive
and conventional varieties tested, he said. Grazing cattle
gained an average of 2.8 pounds per head per day.
The same studies, however, showed
photo-period sensitive sorghum sudangrass had a greater yield
potential and supported higher stocking rates, McCollum said.
In this year's grazing trial, fields
were stocked with 725 pounds of cattle per acre to nearly 1,400
pounds of cattle per acre to look at individual steer gain and
also gain per acre, he said.
The objective is to establish gain
response curves that stocker operators can figure into their
budget projections to determine the most economical grazing
system, McCollum said.
Overall, he said, no statistical
difference in the gain per acre was determined, which means
producers have flexibility in choosing the variety that suits
their operational needs.
"What is best for producers to plant
will be a function of the market and where they are going with
their cattle," McCollum said. "Individual producers may have
different objectives.