Global Warming Reduces Animal Milk Quality

As global temperatures continue to climb, scientists warn that the impacts of climate change extend beyond weather patterns and ecosystems—they are now affecting one of the most fundamental aspects of animal life, milk quality. A recent scientific review titled “Global warming impacts on lactating mammalian milk”, authored by A.N. de São José and published in the journal Science of The Total Environment in November 2025, highlights how heat stress caused by rising temperatures can significantly alter the nutritional composition of milk in both domesticated and wild mammals.

In this review, de São José analyzed 14 studies investigating the effects of heat stress on milk composition. The findings indicate that global warming disrupts key components such as fat, protein, lactose, and total solids (solid-not-fat or SNF). Additional indicators, including somatic cell count (SCC), changes in pH, and reductions in bioactive components like immunoglobulins, were also observed, signaling physiological stress, inflammation, and potential health issues in lactating mammals.

Milk Quality Indicator

The review highlights a consistent pattern, as global temperatures rise, animal milk shows a measurable decline in critical nutritional indicators. These indicators include reductions in milk fat, protein, lactose, and total solids—also known as solid-not-fat (SNF). The research also documents an increase in somatic cell count (SCC), a biological marker associated with inflammation or infection in the mammary glands. Meanwhile, shifts in pH levels and reductions in bioactive components such as immunoglobulins further signal declining milk quality.

From a physical standpoint, milk affected by heat stress tends to appear more diluted, with a thinner consistency due to the loss of total solids. Lower fat and protein levels often make the milk look paler and less creamy. In severe cases, higher SCC levels can make the milk spoil more quickly or become more vulnerable to microbial contamination—posing concerns both for agricultural productivity and food safety.

“Heat stress causes animals to consume less feed and alters internal metabolic processes. This not only decreases milk production but also reduces its nutritional quality,” de São José explained in the report.

Mitigation Strategy

The study demonstrates that global warming has consequences beyond environmental changes, affecting the food chain that relies heavily on milk as a vital source of nutrition. Milk with lower fat and protein content can reduce nutritional value for human consumption and impair the growth and development of mammalian offspring.

Declines in milk quality also pose serious threats to wild mammal populations. Young mammals depend on immune and nutritional components in milk for survival. When heat stress reduces these components, reproductive success and offspring survival rates may be negatively impacted, which could influence population stability in vulnerable ecosystems.

The study highlights the need for mitigation strategies in livestock management, such as the development of shaded areas, cooling systems, and adaptive feed strategies to cope with extreme temperatures. For wildlife, further research is critical to understand the full ecological implications and to support conservation efforts.

Although the body of scientific evidence is limited, the observed trends in declining milk quality are considered consistent and significant enough to serve as a global warning. De São José calls for further studies to evaluate the effects of global warming on additional mammalian species across diverse climatic zones.

Ultimately, the report emphasizes that global warming is not merely an environmental concern, but a direct threat to public health, food security, and ecosystem stability worldwide. (Wage Erlangga)