
Genetic progress at the service of farm operations
10 February 2026Genetics, grazing and longevity: a controlled balance
GAEC DES ROUGES ET NOIRES - COMPOLIBAT (12)
BREEDING IN DETAIL
► 2 partners: Francois BOSC and
Jean Claude VIGUIE
► 600,000 L of milk delivered
► Maximize grazing
► Less than 1.3 tons of concentrate per year per cow
► 3 lactations average for Holsteins
► UAA: 89 Ha
As soon as François and Jean-Claude set up the GAEC, one guiding principle became clear: "make milk with cows that age well".
Here, grass is at the heart of the feeding system. The cows graze on 20 hectares around the barn, from March 10 to the end of November. In winter, they receive a complete ration of corn silage, grass silage and supplementary oil cakes.
As François explains, during the grazing period, the ration at the trough is reduced by two-thirds, and concentrates are completely eliminated: “We want to make the most of our pastures and obtain a good economic margin per liter of milk produced, with an average of 1.2 tons of concentrates per year per cow.
A clear course that is bearing fruit: the herd averages 8,269 kg in 305 days, with solid rates (TP 34.1 – TB 45), which has enabled it to achieve a milk price of €494 in 2024. The PATURE segment seems tailor-made for this breeding operation with its assertive strategy.
On the breeding front, François genotypes all females. The best are inseminated with sexed semen, while around half the herd is oriented towards terminal crossbreeding with YPERIOS 95, to get the best out of the calves.
Genetics follow a clear and assertive vision: “Functionality, longevity and power to make the most of forage. We’ve always been careful not to select cows that are too big. We need robust animals with good legs for grazing”. And the figures bear this out. The herd has an average body condition index of +0.5 and a positive breast width index. Here, we like to age our
cows: last year, the average age at culling was 8 years and 4 months. Functional traits are more than just a criterion, they’re a priority!
With this in mind, a number of bulls have naturally established themselves in the breeding program: TEXY P, TROSCOFF, TONYKROOS, TENNIE, not forgetting cow leader TOPGUN.
Finally, François proudly tells us about his favorite cow: LANGOUSTE.
A great lady of the herd, she has produced over 57,000 kg of milk during her career. She now has three daughters on the farm: RESTELL (in her 4th calf), MOEDIS RED and RITZ P RF. LANGOUSTE, with her solid functional pedigree (VOLADI MAN / BLEUET GDL), perfectly embodies the in-depth work undertaken by François and Jean-Claude over many years.



