Feedlots
Learn to Use Optaflexx
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One of the questions asked when Optaflexx was first offered, could
feedlots work it into their programs? Since it is fed only for a short
period of time, 28 to 42 days, the Optaflexx feed additive required
special rations and care in the execution of the rations at a very
critical time in the feeding program.
One of the things reported to Feed•Lot magazine by feedlot nutritionists
is, “Feedlots have learned to execute the program.” Other
nutritionist report the most convenient way to get the feed additive
into the finish ration is with the “micro-nutrient” machines
that are used at medium and larger feedlots. Another nutritionist
said he suggests his clients consider feeding Optaflexx since it will
usually pay a return for the investment in the additive. But he said
that he reminds his clients the return is not as great as Rumensin
or implants.
Latest large pen research positive
Elanco has undertaken follow-up research supervised by independent
researchers at the agriculture colleges and independent consultants.
For example, the Journal of Animal Science, Midwest Section (2005)
reported a study of 2015 steers fed at Larned, Kansas. Rumensin and
Tylan were fed with the Optaflexx at 200 mg per day. Results as reported
in the abstract report, “Feeding Optaflexx at 200 mg per head
for 29 days prior to slaughter improved live weight gain 16 percent
and hot carcass gain by 17 percent with out affecting quality grade.”
Elanco’s post-registration studies positive
The Elanco team has provided results for their post-registration trials.
These trials included Rumensin and Tylan in the feeding program plus
implants were also used (Laudert, et al. 2004. Optaflexx Exchange
#4, Elanco Animal Health A19725). The six trials demonstrated a significant
advantage of 14.8 lb live weight a 12.3 lb carcass increase for the
200 mg per day of Optaflexx. However, as expected some trials gave
more response than others. For example the increase in carcass weight
increased from 6.4 to 17.8, but all the responses were positive.
“What we know”
At the Plains Nutrition Council 2005 Spring Conference, Dr. Robbi
Pritchard discussed “what we know about Optaflexx and what we
would like to know.” Dr. Pritchard is a professor at South Dakota
State University. He explained what we know is the mode of action
of this product, that we can expect a ‘biologically and economically
improvement in cumulative average daily gain and feed/gain even in
cattle fed for 150 days.” He further added that what we know
about the mode of action of implants and adrenergic agonists could
be interpreted to expect them to be additive in growth promotion.
What we would like to know
Pritchard raised several questions at the conference. “Is there
a break point between 28 and 42 days to achieve maximum growth and
carcass weight?” He suggested that possibly heifers and calves
will need 300 mg rather than 200 mg: “In these types of cattle
can more days at 200 mg/day achieve the same results as 300 mg/day
for fewer days?”
He indicated a more immediate need is the tolerance response for big
and light intake pens. For example, if a batch is formulated for 21
lb of intake, then a pen with low intake versus a pen at high intake
will have a large variation in the dose of Optaflexx. Will we have
to fine tune our feeding program for extra small or large intakes
from our average pen? Feedlots like to make large batches for several
pens.
He also asks, “Is there a point where the product will not be
cost effective in lower intake, lower performance cattle.”
Ration formulation
Up to now, the recommendations are for high energy /adequate protein
finishing rations. However several feedlot nutritionists, have asked
is there a caution for very low protein finishing rations when Optaflexx
is used. Some feeders may be using a ration as high as 16 percent
crude protein with co-products and while other feedlots may be using
rations as low as 11 percent protein if the grain may be low in protein
content. We know from swine research that the extra protein or increased
essential amino acids are needed when feeding this additive. ©
Comments on this or any article by Dr. Sprague can be addressed to
him at 625 Grandview, Newton, KS 67114, or call (316) 283-8692.
