Quick Reference to ASA EPDS and Indexes
$ Indexes Though EPDs allo w comparison of genetic le v els for man y economicall y important traits , the y represent onl y part of the economic picture . That ’ s w here $ inde x es come in — combining EPDs and economics through rigorous calculation to estimate an animal ’ s o v erall impact on y our bottom line . All-Purpose Index (API) E v aluates sires for use across the entire co w herd ( bred to both first - calf heifers and mature co w s ), w ith enough daughters retained to maintain herd si z e and the remaining heifers and steers fed and sold on grade and y ield . Terminal Index (TI) Evaluates sires for use across the entire cow herd (bred to both first-calf heifers and mature cows), with enough daughters retained to maintain herd size and the remaining heifers and steers fed and sold on grade and yield. E v aluates sire for use on mature Angus co w s w ith all offspring put on feed and sold grade and y ield . Using API and TI First determine w hich inde x to use — API if y ou are keeping replacements , TI if not . As w ith EPDs , focus on the dollar difference bet w een bulls ( inde x units are dollars per co w e x posed ). This difference helps determine ho w much more one bull is w orth than another . For e x ample , an all - purpose sire scoring + 100 API is w orth about $ 6 , 000 more than a + 50 bull if both are e x posed to 30 co w s o v er four y ears ($ 50 × 30 × 4 = $ 6 , 000 ). A percentile chart is needed to see ho w a bull ’ s inde x ranks w ithin the breed . For percentile rankings or more detailed information on EPDs and $ inde x es , v isit www . simmental . org . First determine which index to use — API if you are keeping replacements, TI if not. As with EPDs, focus on the dollar difference between bulls (index units are dollars per cow exposed). This difference helps determine how much more one bull is worth than another. For example, an all- purpose sire scoring +100 API is worth about $6,000 more than a +50 bull if both are exposed to 30 cows over four years ($50 × 30 × 4 = $6,000). A percentile chart is needed to see how a bull’s index ranks within the breed. For percentile rankings or more detailed information on EPDs and $ indexes, visit www.simmental.org. Though EPDs allow comparison of genetic levels for many economically important traits, they represent only part of the economic picture. That’s where $ indexes come in — combining EPDs and economics through rigorous calculation to estimate an animal’s overall impact on your bottom line. Evaluates sire for use on mature Angus cows with all offspring put on feed and sold grade and yield. Calving Ease Star All Bull lots ha v e a Cal v ing Ease Rating . This is a star rating s y stem to help y ou select bulls based on ho w w e belie v e the y w ill cal v e . Al w a y s remember that the co w contributes 50 % of the genetics and this should be taken into consideration w hen making y our final mating decisions . All Bull lots have a Calving Ease Rating. This is a star rating system to help you select bulls based on how we believe they will calve. Always remember that the cow contributes 50% of the genetics and this should be taken into consideration when making your final mating decisions. CALVING EASE STAR DEFINITIONS
CE Score
Fi v e and four stars can be used on v irgin heifers w ith confidence Five and four stars can be used on virgin heifers with confidence
CE Score
Potential heifer bull , should be used on y oung co w s first Potential heifer bull, should be used on young cows first
CE Score
Acceptable cal v ing ease , but should not be used on heifers Acceptable calving ease, but should not be used on heifers
CE Score
Terminal sire , should be used on mature co w s onl y . Terminal sire, should be used on mature cows only.
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