Santa Gertrudis Source January 2025

EMPOWERING BREEDING DECISIONS Continued from 12

traits include calving ease; birth, weaning and yearling weights; and end-product traits like carcass weight, mar bling, ribeye area and fat thickness. Three separate, endpoint-defined selection in dexes are computed based on reported EPDs. The selection index tools are particularly useful for commercial producers to simplify selection processes. The indexes distill EPDs into a single value of net merit to a particular endpoint. Commercial producers should use the index with the production scenario and assumptions that most closely describes their own operation. The Balanced Index assumes a commercial producer will keep replacement heifers and sells either carcasses priced on a value-based grid or that buyers of their feeder cattle base pricing on feedlot/carcass performance. Many large operations will fit this description. The Cow/Calf Index as sumes a producer keeps replacement heifers from the bulls they purchase and that calves are marketed at weaning, fitting the production scenario of many small and medium sized producers. The Terminal Index assumes producers don’t keep replacements (no economic weighting of ma ternal traits), and calves are sold on a value-based carcass grid. SGBI and its members have made sound investments in genetic-improvement tools. Now’s the time to make sure you are using them to your advantage and positioning your commercial customers for profit and success!

is the concept that if a group of animals all have the same nutritional and physical environment, then differences ob served in their performance is due to genetics. Of course, we have to make sure that the competition is fair, otherwise ge netic predictions include bias from non-genetic sources. In dividual performance observations are adjusted for known non-genetic effects. These non-genetic effects include age of calf, age of dam and contemporary group. Evaluated Traits The genetic evaluation system leverages the ge nomic and traditional data to produce genetic predic tions across a range of economically important traits. The suite of traits is designed to address the need for improvement in merit across a whole range of traits in value chain. Included in the suite are maternal traits like maternal calving ease and milk. Maternal traits ac count for the genetic effects in those characteristics exhibited by a cow that affect her calf’s performance. One way to think about maternal traits is that they are the heri table components of the environment a cow provides for her calf. Fertility traits are estimated through Scrotal Cir cumference, Heifer Pregnancy and Breed-Back EPDs. Di rect traits are those exhibited by a calf and influenced by both paternal and maternal genetic contributions. These

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SANTA GERTRUDIS SOURCE

JANUARY 2025