Heatwave kills 700,000 French layers — more than bird flu all season

Published on : 29 Jul 2026

Up to 700,000 laying hens died in France during the heatwave that struck the country in late June — more birds than France lost to avian influenza across the entire 2025/26 season, with losses skewed towards free-range and organic flocks housed in statically ventilated sheds.

First estimates from the CNPO, the French egg interprofession, put the losses at between 1% and 1.5% of the national laying flock. Director Alice Richard said the figure was drawn from a study across the organisation's producer network, with returns from production organisations still incomplete.

"We lost more hens during this heatwave than to avian influenza over the 2025/26 season," she said, in comments to Les Marchés translated from the French.

Deaths were recorded in every system — cage, barn, free range and organic — but ventilation type, not production system, determined survival. Older sheds relying on static ventilation could not cope with temperatures above 40°C sustained over several days, while dynamically ventilated buildings came through with manageable losses. Ms Richard told Réussir Volailles that static ventilation was mostly found in free-range and organic laying systems, where the consequences were heavier — but she noted that very old cage buildings, no longer fit for purpose, also recorded high mortality.

Ms Richard said recent buildings were better insulated and constructed with dynamic ventilation as standard, and that the age of housing had made the difference between heavy and manageable losses. Pullet flocks escaped: to her knowledge, no rearing flocks were affected.

Brittany and Pays de la Loire, regions unaccustomed to heatwaves, were the worst hit; producers in the south, better prepared for high temperatures, fared less badly. Some producers in Brittany, France's biggest egg-producing region, lost 30% of their flocks, according to reports carried by France 3. Rendering industry data gives a measure of the peak: poultry mortality in Normandy and Pays-de-la-Loire ran at 1,000% above normal during the hottest days, against rises of 200% in pigs and 45% in cattle. Rendering services were saturated during the peak, leaving dead birds uncollected on farms — an experience Ms Richard said had often been traumatic for producers with heavy losses. The broiler sector lost a further 2.5 to 3 million birds, according to the meat interprofession Anvol, with Label Rouge and other quality meat flocks hit hardest because their production specifications prohibit dynamic ventilation.

The supply consequences will run for months. Surviving hens are laying fewer eggs and average egg weights have dropped. French single-batch flock rules prevent producers from restocking partially depleted sheds mid-cycle, so affected units will run below capacity until depopulation. Abattoirs worked at full capacity through July processing spent hens, with exports to Africa slowed by a shortage of shipping containers.

The losses hit a French market already short of eggs. Supplies have been tight since the start of the year, when shelf availability fell sharply after the January cold snap, and the CNPO said it was watching all fluctuations closely.

Sources
Les Marchés (Réussir), "Canicule : 500 à 700 000 poules pondeuses perdues, des conséquences à moyen terme en œufs", Virginie Pinson, 3 July 2026 — CNPO estimate, Alice Richard quotes, all-systems losses, single-batch restocking rules


Réussir Volailles, "Canicule en élevages de volailles : l'âge des bâtiments et les systèmes de ventilation ont fait la différence sur la mortalité", Armande Dupuis, 9 July 2026 — ventilation and building age analysis, old-cage detail, 40°C figure, pullet flocks unaffected, regional pattern, rendering saturation, Anvol broiler losses, Label Rouge ventilation specification


Reporterre, "Canicule : près de 700 000 poules pondeuses sont mortes en France", 20 July 2026 — Brittany 30% flock losses (via France 3), 700,000/1.5% confirmation


Les Marchés (Réussir), "Canicule : on constate des mortalités de +1000 % sur la volaille, +200 % en porc, +45 % en bovins en Normandie et Pays-de-la-Loire" — rendering industry mortality data


Les Marchés (Réussir), "Prix des poules pondeuses – Cotation réalisée le 10 juillet 2026", Bastien Lelandais, 12 July 2026 — abattoir capacity, Africa container shortage


Process Alimentaire, "Tensions sur le marché de l'œuf, la filière fait le point", 13 January 2026 — French market tightness since the start of the year