Enhanced comment feature has been enabled for all readers including those not logged in. Click on the Discussion tab (top left) to add or reply to discussions.
Ultrasound intramuscular fat: Difference between revisions
No edit summary |
|||
| Line 19: | Line 19: | ||
If the trait is not adjusted (e.g. Stayability) then say so | If the trait is not adjusted (e.g. Stayability) then say so | ||
--> | --> | ||
Percentage of intramuscular fat is adjusted to a common age (e.g., 365 days of age) and in | Percentage of intramuscular fat is adjusted to a common age (e.g., 365 days of age), and in multiple-breed settings is also adjusted for breed composition. | ||
===Contemporary Grouping=== | ===Contemporary Grouping=== | ||
| Line 34: | Line 34: | ||
E.g., direct, maternal, permanent environment due to dam. | E.g., direct, maternal, permanent environment due to dam. | ||
--> | --> | ||
Given the ultrasound measure is an indicator of the economically relevant trait of carcass marbling, it is generally included in | Given the ultrasound measure is an indicator of the economically relevant trait of carcass marbling, it is generally included in multiple-trait models that include carcass marbling and potentially other carcass-fat-related traits (e.g., back fat). There are no maternal effects fitted for ultrasound or carcass traits given the maternal influence declines post-weaning. | ||
===Usage=== | ===Usage=== | ||
Revision as of 15:20, 11 December 2019
Phenotype
Percentage of intramuscular fat (% IMF) is correlated with USDA marbling score. A minimum of four independent images should be collected and the resulting % IMF predictions averaged for this trait. The % IMF measurement is made from an image that is collected across the 11th-13th ribs (or 12th-13th ribs) at a lateral position from the animal’s midline at a point three fourths of the distance from the medial end of the longissimus dorsi muscle. Ultrasound technicians and image processing labs should be certified or accredited by the Ultrasound Guidelines Council.
Adjusted Value
Percentage of intramuscular fat is adjusted to a common age (e.g., 365 days of age), and in multiple-breed settings is also adjusted for breed composition.
Contemporary Grouping
Animals of the same sex, reared and managed together up until the time of scanning form a contemporary group. Scanning contemporary group definition includes the following: herd code, weaning date, weaning management group (pasture, creep, non-creep, etc.), scanning date, and post-weaning management group designation. For animals scanned at a central test, the contemporary group definition for an animal should include its herd of origin and other birth and weaning contemporary group information.
Genetic Evaluation
Given the ultrasound measure is an indicator of the economically relevant trait of carcass marbling, it is generally included in multiple-trait models that include carcass marbling and potentially other carcass-fat-related traits (e.g., back fat). There are no maternal effects fitted for ultrasound or carcass traits given the maternal influence declines post-weaning.
Usage
Most organizations publish only the marbling EPD and not an IMF EPD because IMF is not an ERT.
