Climatic Variability and Milk Quality as Sustainability Indicators in Dairy Farming Systems of Pastaza Province, Ecuador.

Milk production in humid tropical regions depends heavily on environmental conditions, yet little is known about how climatic variability affects milk quality in small-scale dairy systems in the Ecuadorian Amazon. This study examined the link between climatic variability and the physicochemical and microbiological quality of raw milk on dairy farms in Pastaza Province, Ecuador. Researchers collected and analyzed 127 milk samples in 2024 for fat, protein, total solids, and solids-not-fat using an automated milk analyzer. They also measured somatic cell count and total bacterial count as microbiological indicators. Climatic data, including precipitation, mean temperature, evaporation, relative humidity, cloud cover, and wind speed, were obtained from official meteorological records and analyzed using generalized linear models and multivariate analysis. The physicochemical makeup of milk remained stable despite climate change, indicating that tropical pasture-based dairy systems exhibit some productive resilience. By contrast, microbiological indicators, especially somatic cell count, varied more and were sensitive to environmental factors such as wind speed. These results show that milk composition remains stable under humid tropical conditions, whereas sanitary indicators respond more to climate variability. Better management and hygiene are crucial to maintaining sustainable dairy production systems in these environments.