French scale

Sire search on the French scale

More Genomic Breeding Values on the French scale

What is ISU and gISU?

The ISU for “Production and Functionality” is the total merit index that is used in France for ranking bulls according to the French breeding goal. As soon as genomic information is available, gISU can be computed.

What are the benefits of using ISU?

ISU is a balanced breeding goal that aims at creating cows with a high production level of milk and protein and with the ability to spend many lactations in the herds. ISU allow to select on functional morphology.

How to understand ISU?

  • 95% of the bulls of the Holstein animals evaluated in France have breeding values between 66 and 144.
  • This means that bulls with a proof over 144 represent the top 2.5% of the breed.
  • Breeding values on the French scale have an average of 100 and a genetic standard deviation of 22.

Who is responsible for estimation and publication of breeding values?

  • GENEVAL is computing genomic breeding values on a weekly basis for more than 30 single traits and 7 groups of traits, including calving traits.
  • IDELE is responsible for the publication of official breeding values.
  • VALOGENE is responsible for the distribution of unofficial genomic breeding values, for all males and females with a genotype, every week.

Where do you search for the ISU of a specific sire?

ISU and all other breeding values calculated by GENEVAL can be found on the IDELE official website (official proofs). Bulls can be searched for by clicking on 'more criteria' and filling out the international ID (breed (3 digits) + country code (3 digits) + sex (M) + 12 digits). Get also young bulls' monthly publications here (select the monthly publication of interest on the right part of the page. The files are available at the bottom). 

Where do you find more information on French proofs?



gISU: 6 groups of traits

The ISU is composed of breeding values for 6 groups of traits with their respective weights:



Press publication

Press publication of the official breeding values takes place 3 times a year on the following dates:


  • Wednesday 6 April 2022
  • Wednesday 10 August 2022
  • Wednesday 7 December 2022

and new genotyped animals on the following dates can be found here

  • Tuesday 4 January 2022
  • Tuesday 1 February 2022
  • Tuesday 1 March 2022
  • Tuesday 3 May 2022
  • Tuesday 7 June 2022
  • Tuesday 5 July 2022
  • Tuesday 6 September 2022
  • Tuesday 4 October 2022
  • Tuesday 1 November 2022