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MEANING OF $ INDEXES FOR SIM ANGUS & SIMMENTAL
Though EPDs allow for the comparison of genetic levels for many economically important traits, they
only provide a piece of the economic puzzle. That’s where $ indexes come in. Through well-conceived,
rigorous mathematical computation, $indexes blend EPDs and economics to estimate an animal’s over-
all impact on your bottom line. The same technology that led to the dramatic progress in swine, poultry
and dairy genetics over the last several decades was used to develop the following $ indexes:
All-Purpose Index (API):
Evaluates sires for use on the entire cow herd (bred to both Angus first-calf
heifers and mature cows) with the portion of their daughters required to maintain herd size retained and
the remaining heifers and steers put on feed and sold grade and yield.
Terminal Index (TI):
Evaluates sire for use on mature Angus cows with all offspring put on feed and
sold grade and yield.
Using API and TI: First, determine which index to use; if you’re keeping replacements use API,
if not, TI.
Then, just as with EPDs, zero in on the unit difference between bulls. (As described above,
index units are in dollars per cow exposed.) The difference can be used to determine how much a bull
is worth compared to another. Or, put another way, how much you can pay for one bull compared to
another. For example, when buying an all-purpose-type sire, you can quickly figure a bull scoring +100
for API is worth an extra $6,000 over a +50 bull if both are exposed to 30 cows over 4 years ($50 diff.
x 30 hd. x 4 yr. = $6,000). A percentile-ranking chart is required to determine where a bull’s index value
ranks him relative to other bulls in the breed.
FOR PERCENTILE RANKINGS OR MORE DETAILED INFORMATION ABOUT EPDS AND
$ INDEXES VISIT
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FEEDING OF BULLS
Cattle raised on the Pelton farm are not pampered or overfed, but they are also not shorted on
nutrients that contribute to proper development of structure, capacity and reproductive performance.
The cow herd runs seasonally as a commercial herd would on range, stalks or dry lot forages with
access to a high quality Vigortone mineral supplement and additional protein or energy as the
season requires. Heifers are grown with frame, capacity and future fertility and milking ability in mind.
Bulls are developed with two goals:
1. Allow the bull to express his natural ability for gain and carcass quality; demonstrating a
good weight per day of age.
2. Produce a bull capable of going to a new home under commercial conditions that will be
able to travel and breed cows.
Bull rations are low in starch and high in digestible fibers, producing good gains without the health
and over conditioning problems associated with high corn, feedlot type rations. A custom Vigortone
pellet provides vitamins, minerals and Rumensin on a soy hull based carrier while wet distillers
grains add protein and energy to the mix without extra starch. A small amount of corn silage and
mixed hay make up the rest of the diet producing a medium energy mix that builds big, strong, high
capacity, high fertility bulls that don’t crash when put out in the breeding pasture.
John Marks
Nutrition Specialist – Vigortone Ag Products
