Page 18 - Aug242023

The Midwest Cattleman · August 24, 2023 · P18
$API and $TI — A Bull Buyer’s Best Friends

by Lilly Platts

Utilizing indices in bull se- you may have a simple ap- you, simplifying the process is use $API or $TI as a starting
lection decisions. proach and assess bulls the beneficial. point in their decision-mak-
day-of with your eye on a few Indices take into account ing process.
Bull selection impacts a select criteria. Either way, many EPD and combine them
cow herd for many years, the bull you want is going to into one value, expressed in How should each index be
often long after the bull has walk through the sale ring or dollars of profitability predic- used?
left an operation. You might across your screen, and you tion among bulls. ASA pub- Seedstock breeders have
spend months leading up to will have a small window of lishes two indices: $API (All the responsibility of improv-
sale season combing through time to balance the cost of the Purpose Index), and $TI (Ter- ing the genetics that influence
catalogs, studying numbers, bull and the criteria he meets minal Index). $API estimates the entire commercial beef
making phone calls, and put- (or doesn’t). Even if you have profitability when a percent- industry. Because of this, the
ting in the time to make sure a longstanding relationship age of daughters remain in goal of commercially minded
your selection will live up to with a seedstock breeder or a the herd as replacements. $TI breeders should be to develop
your operation’s needs. Or, buyer who picks out bulls for estimates terminal profitabil- genetics that are commercial-
ity. ly viable and profitable. An
An index is not an EPD, economic index helps with
but rather a measure of the this goal.
difference in profitability for Instead of breeders select-
the designed scenario. While ing animals based on individ-
an index can be an extreme- ual traits related to a single
ly useful tool, other EPD still aspect of an operation’s profit-
matter; for example, an ani- ability (i.e., Weaning Weight,
mal with an extremely high Calving Ease, etc.), an eco-
marbling EPD may cover a nomic index combines all eco-
bad calving ease number. Un- nomically relevant traits and
derstanding each index can weights their importance in a
help you move the profitabil- single value — one expressed
ity of your cow herd in a posi- in dollars.
tive direction. If your goal as a breeder is
Lane Giess, ASA Geneti- to develop genetics with the
cist, answers some common intention of retaining females
questions about index selec- and being more maternally
tion. focused, then the All Purpose
Index ($API) is the one you
Why is it important to should use. This index focus-
have $API and $TI? es on the whole-life-cycle and
Why is there value in accounts for traits such as
simplifying things? maternal calving ease, docili-
An economic index such as ty, fertility, and, perhaps most
$API or $TI greatly improves importantly, female longevity.
a breeder’s ability to select for As a whole-life-cycle index,
genetics associated with com- the $API still needs to ac-
mercial profitability. With- count for carcass performance
out the use of an index that since many of the daughters
accounts for all traits, select- will contribute to the termi-
ing for balanced genetic im- nal genetics of their progeny.
provement is too burdensome. On the flip side, if your
Commercial cattlemen can goal as a breeder is to devel-
use a single value to simpli- op genetics with the sole pur-
fy their selection criteria and pose of maximizing terminal