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Ultrasound intramuscular fat: Difference between revisions

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[[Category:Carcass Traits]]
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===Phenotype===
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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.
Percentage of intramuscular  fat  (%  IMF)  is correlated  with  USDA marbling score. A  minimum  of  four independent images should be collected, and the resulting % IMF measurement is the average of the images.  The  %  IMF  measurement  is  made  from  images that  are 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 [https://ultrasoundguidelinescouncil.org/locate-technicians-or-lab/ technicians and image processing labs] should be certified or accredited by the [https://ultrasoundguidelinescouncil.org/ Ultrasound Guidelines Council] (UGC). The UGC standards for certification can be found at https://ultrasoundguidelinescouncil.org/wp-content/uploads/2021/09/UGC-SG-VII-FC.pdf.


===Adjusted Value===
===Adjusted Value===
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     If the trait is not adjusted (e.g. Stayability) then say so
     If the trait is not adjusted (e.g. Stayability) then say so
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Percentage of intramuscular fat is adjusted to a common age (e.g., 365 days of age) and in multi-breed settings is also adjusted for breed composition.
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===
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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.
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.
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     E.g., direct, maternal, permanent environment due to dam.  
     E.g., direct, maternal, permanent environment due to dam.  
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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===
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     Discuss in what circumstances the trait is an ERT or an indicator trait and how the trait should be used and not used.
     Discuss in what circumstances the trait is an ERT or an indicator trait and how the trait should be used and not used.
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Most organizations publish only the marbling EPD and not an IMF EPD because IMF is not an ERT.

Latest revision as of 17:08, 21 October 2021

Percentage of intramuscular fat (% IMF) is correlated with USDA marbling score. A minimum of four independent images should be collected, and the resulting % IMF measurement is the average of the images. The  % IMF measurement is made from images that are 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 (UGC). The UGC standards for certification can be found at https://ultrasoundguidelinescouncil.org/wp-content/uploads/2021/09/UGC-SG-VII-FC.pdf.

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.