What You Need to Know About the Updated $API and $TI – Part 2

*These are average index values for animals born after January 1, 2024.

● Use percentile rankings to make comparisons between previous and updated index values.

$API (All-Purpose Index) Definition:
● Evaluates sires for use on an Angus cowherd with a portion of their daughters retained and the remaining offspring put on feed and sold on a grid.
● Use if you are retaining females.
● Expressed as the dollar difference per head exposed. A higher value is more favorable.

$TI (Terminal Index) Definition:
● Evaluates sires for use on an Angus cowherd with all offspring put on feed and sold on a grid.
● Use in a terminal breeding program where all progeny are destined for the feedlot.
● Expressed as the dollar difference per head exposed. A higher value is more favorable.

What This Means for Bull Selection:
Two selection candidates:
● Bull A - $API = 275
● Bull B - $API = 350
● Difference in $API = 75

What does the $75 difference in $API mean?
● Assuming each bull is exposed to 30 head each year for 4 years, then a $75 index difference x 30 progeny per year x 4 years = $9,000
● A $75 difference in $API translates to an expected $75 difference in progeny profitability per calf. Across a bull’s service lifespan, that difference adds up.
● Economic selection indexes estimate differences in expected progeny profitability under a defined production scenario. They do not represent guaranteed returns or the amount a bull should cost.