Avian influenza has been around for decades. But in early 2022 a new outbreak of highly pathogenic avian influenza (H5N1) hit flocks of egg-laying hens across the United States, leading to almost continuous outbreaks across multiple states. These outbreaks, and the subsequent loss of hens due to the disease and the long-standing “depopulation” program intended to eradicate the disease, have led to the loss of more than 60 million U.S. egg-laying hens from 2022 through 2024. In California, the disease led to the destruction of around 10.6 million laying hens, with another 1 million table-egg pullets (young hens about to start laying) also destroyed.
Production decreases coincided with the rising egg prices that jumped in 2022 and again dramatically at the end of 2024, with national wholesale egg prices clearing $5 per dozen and California egg prices rising above $7 per dozen. California's regulations state that only cage-free eggs may be produced or sold here, raising average prices in normal times and accounting for higher volatility in egg prices for California consumers.
In August 2024, H5N1 was detected in California dairies and spread rapidly. As of late January 2025, nearly 75% of California herds had been infected. In contrast to its high mortality in birds, H5N1 has mostly produced more mild symptoms in dairy herds. Individual cows are typically asymptomatic after around a month, and milk production, which may fall temporarily by 20% or 30%, takes a few more months to recover. Importantly, even in infected herds, a large share of cows shows no loss of milk production. The authors estimate that California milk production fell by 6.4%, 10.3%, and 8.4% in October, November and December 2024, compared to what would have occurred without the disease.
While consumers may not feel the effects of H5N1 through rising dairy prices, affected dairy producers have experienced major losses in net returns, which will continue as their herds recover in 2025.
Source : ucanr.edu