The environmental management of the barn represents a key factor for the welfare of dairy cows and for the quality of milk intended for DOP production. Continuous environmental monitoring, thanks to non-invasive multi-sensor technologies, now makes it possible to collect objective data on gases harmful to animals and the environment (NH₃, CO₂, CH₄, H₂S), particulate matter (PM10 – PM2.5), better known as fine dust and volatile organic compounds (VOC) and brightness, providing reliable indicators to optimize ventilation, prevent diseases and measure environmental impact.
This contribution offers a specific overview of the concrete opportunities that continuous environmental monitoring can offer to dairy barns such as those of the Parmigiano Reggiano supply chain, for example, with the aim of improving productivity, animal welfare and sustainability to face the new global challenges in an increasingly aware and competitive market.
Air Quality and DOP Production
The quality of the environment inside farms is a fundamental aspect for the health and productivity of dairy cows. In supply chains where milk must meet very high quality criteria, environmental conditions represent a very important element to ensure animal welfare, reduce diseases and preserve cheese yield.
Gases and Particulate Matter in Barns: Effects on Cows and Workers
The accumulation of gases such as ammonia (NH₃), carbon dioxide (CO₂), methane (CH₄), hydrogen sulfide (H₂S), fine particulate matter (PM10 and PM2.5) or volatile organic compounds (VOC) can cause respiratory problems, stress, infections and worsen the quality of the working environment.
These effects concern:
The cows: with drops in milk production, behavioral changes, increased respiratory diseases;
The workers: with health risks and reduced quality of work.
Brightness: An Often Underestimated Parameter
In addition to air quality, brightness in the barn, in particular the management of the photoperiod in critical seasons, also plays a crucial role in the productivity and welfare of dairy cows. Several studies, one from 2021 and a review from 2025 in particular, have shown that prolonged exposure to controlled and optimal light levels can increase milk production by up to 10–15%, while at the same time improving the immune response and metabolic activity of the animals.
The ideal photoperiod for lactating cows is generally between 14–16 hours of light per day, with a light intensity not lower than 300–400 lux in feeding and milking areas. On the contrary, during the dry phase, a reduction of the photoperiod (8 hours of light) is recommended to promote physiological recovery and the subsequent productive restart.
Light acts by regulating the circadian rhythm and melatonin secretion, influencing appetite, hormonal activity and behavior. A continuous monitoring system of brightness can therefore contribute to:
Optimize visual comfort and photoperiod
Promote feeding and mobility
Support a more regular and constant milk production
Reduce stress during nighttime phases or in more sensitive subjects
Integrating this parameter into environmental management systems means completing the picture of welfare and productivity, aligning with the most advanced standards of high-quality dairy farming.
Regulations and Reference Thresholds
The air quality in dairy barns is influenced by various gaseous and particulate pollutants produced by animal management. Among the main harmful substances generated in farms are ammonia (NH₃), methane (CH₄), nitrous oxide (N₂O), volatile organic compounds (VOC) and hydrogen sulfide (H₂S).
On the animal welfare front, official indications have recently been introduced regarding the allowable concentrations of some gases in dairy barns. In the National Quality System for Animal Welfare (SQNBA) – a regulation approved at the end of 2024 by MASAF and the Ministry of Health – environmental requirements are established in cattle barns. In particular, for adult animals the concentration of some harmful gases must remain within precise limits: ammonia < 20 ppm and carbon dioxide < 3000 ppm.
These thresholds derive from the fact that higher levels are irritating or harmful: already over 20 ppm of NH₃ signs of irritation (e.g. redness of the eyes and tearing in cows) and drops in immune defenses are observed, mainly due to the flattening of the nasal cilia. In the ClassyFarm manual for cattle, in fact, air quality is considered “acceptable” if NH₃ < 20 ppm and CO₂ < 3000 ppm, while it becomes “insufficient” if it exceeds these values (considered harmful). These are technical guidelines for welfare, not a general law, but they are official: veterinary health authorities use them during inspections and farms participating in welfare certifications must comply.
Even supranational scientific bodies such as EFSA have reiterated the importance of maintaining a low concentration of ammonia (< 10 ppm) and other irritant gases in barns: high levels of NH₃ and fine dust make cows more vulnerable to respiratory diseases.
Therefore, even in the absence of a single specific regulation, a network of official technical guidelines (Ministry of Agriculture, Ministry of Health, ISPRA, Regions, ASL) has been formed defining air quality parameters to be respected in farms, at least as recommendations or as a requirement for the recognition of good practices. The existing thresholds aim both to protect the animals (welfare and productivity) and to safeguard the workers and the surrounding environment.
With technological progress in the livestock sector, an important unknown factor affecting welfare and productivity has been addressed: the environmental conditions in which animals live. The presence of gases in the barn is a real phenomenon, with direct effects on the welfare of cows, the health of operators and the quality of milk.
Although the guidelines may already seem very restrictive, real cases show that “to significantly improve productivity and animal performance,” environmental parameters are rewriting the way of farming precisely through precision livestock farming.
Scientific Studies and Case Studies
Inside barns (especially free-stall housing), various gaseous pollutants and particulate matter accumulate that can influence the health and productivity of dairy cows. The main substances monitored are: ammonia (NH₃) produced by the degradation of urea in manure, carbon dioxide (CO₂) from respiration and fermentation, methane (CH₄) from enteric fermentations, hydrogen sulfide (H₂S) from anaerobic decomposition of slurry, in addition to volatile organic compounds (VOC) and fine particulate matter (PM₁₀ and PM₂.₅). Under conditions of inadequate ventilation, the concentrations of these pollutants can rise well above normal ambient levels: for example, external CO₂ (~420 ppm) can reach 1000–5000 ppm in the indoor air of a poorly monitored barn. Similarly, NH₃ in barns typically varies from 5 to 10 ppm.
The Key Role of Indices. One of the most concrete and useful developments of continuous environmental monitoring is the possibility of accessing synthetic indices, designed to simplify the interpretation of data collected in the barn.
These tools transform complex parameters (gases, temperature, dust, humidity, etc.) into readable, operational, and prevention-oriented information. For the farmer, this means being able to rely on simplified technical language, useful for making quick, effective, and documentable decisions.
Among the environmental indices most used today in dairy barns:
THI – Temperature Humidity Index: one of the best known, it is useful for assessing the risk of heat stress and anticipating interventions such as ventilation or cooling before production drops or fertility worsens.
Respiratory risk index: provides an overall assessment of air conditions, combining the presence of gases and other environmental parameters to evaluate environments more favorable for pathogenic bacteria and viruses responsible for coughs and other respiratory problems.
Animal welfare index: provides an integrated view of the comfort perceived by cows, based on environmental parameters and herd management. It is useful for monitoring how the microclimate affects health, feed intake and behavior.
Air Quality Index for operators (AQI): often overlooked, this indicator also supports the assessment of occupational risk, useful for improving safety, work shifts and operator welfare in the barn.
Predictive heat stress index: by integrating current conditions and trends, it allows anticipation of heat waves or critical moments during the day, for more strategic management.
The daily use of these indices in dairy barns makes it possible not only to intervene before problems arise, but also to make the farming system more aware, traceable and proactive. Dairy cows, by their nature, are highly productive animals but sensitive to environmental variations: knowing the environment through these indices means putting them in the best condition to express their potential.
Furthermore, the simplified interface with which the indices are usually presented—often in intuitive graphical dashboards—makes these tools accessible even to non-technical staff, improving information sharing among farmers, company veterinarians, barn technicians and consultants.
Finally, the historical recording of indices makes it possible to build objective documentation supporting sustainability, animal welfare and quality pathways, in line with the increasingly demanding standards of DOP supply chains such as Parmigiano Reggiano.
Studies on animal welfare indicate threshold values of safety. Scientific research agrees that a deterioration in the internal environmental quality of the barn has measurable and significant effects on dairy cows. In summary:
Heat stress (high THI): leads to reduced milk production (up to 10–20% less during heat waves), deterioration in milk fat and protein percentages (fat reduced by 20–40% in severe heat stress), increased somatic cell counts and higher risk of mastitis. Fertility drops dramatically (conception rates halved or worse in summer, 10–20% vs ~40% in cool periods). Chronic heat stress also impacts welfare: cows under prolonged heat stand longer, eat less, and are predisposed to ruminal acidosis and laminitis. Increased embryonic mortality is also observed.
Ammonia and harmful gases: high NH₃ (>10 ppm) irritates airways, increasing incidence of bronchitis, pneumonia and bovine respiratory disease. This leads to greater indirect production losses: sick cows breathe poorly, eat less and produce less milk. Moreover, subclinical respiratory infections in young animals result in less productive cows as adults, losing several quintals of milk in the first lactation. High levels of ammonia are also indicative of poor hygiene (accumulated manure) and correlate with environments rich in environmental pathogens (coliforms, etc.) which can increase mastitis and somatic cell counts. Workers are also affected: breathing ammonia and dust causes eye irritation, chronic cough and allergic diseases in workers, with serious occupational health issues, higher turnover, extra company costs and longer operating times.
Dust (PM₁₀/PM₂.₅): a dusty environment causes chronic respiratory damage and systemic inflammation. Cows exposed to fine dust show increased cortisol (stress indicator) and metabolic changes that can reduce production efficiency. There is evidence that high PM₂.₅ correlates with reduced milk production and increased somatic cell counts regardless of other factors.
Experimental and on-farm data confirm the importance of monitoring and managing parameters such as NH₃, dust and THI: interventions to reduce NH₃ (e.g. bedding cleaning, proper nitrogen feed management), lower dust (humidification, cleaning, forage and feed management) and cool the environment during heat can prevent significant production losses. This approach also improves animal welfare, reducing heat stress and respiratory diseases, with ethical and economic benefits for the farmer. Dairy cows are highly productive but also sensitive to the environment: ensuring good air quality and thermal comfort is essential to fully exploit their productive potential without compromising health and fertility.
Continuous Environmental Monitoring: What It Measures and Why It Is Useful
This technology uses IoT – AI (Internet of Things) sensors with applied artificial intelligence capable of measuring in real time parameters such as: NH₃, CO₂, CH₄, H₂S, PM10, PM2.5, volatile organic compounds (VOC), temperature and humidity (for THI calculation), brightness and photoperiod.
The data are automatically recorded and aggregated to provide predictive indices, useful to: optimize management to increase productivity; activate or adjust ventilation and lighting systems; identify critical areas in the barn; prevent conditions favorable to diseases.
These advantages translate into direct savings: for example, avoiding energy waste linked to continuous forced ventilation, often activated by sensors not positioned at animal height. Similarly, an effective cooling system must consider not only ambient humidity, but also that perceived by cows and all other environmental parameters fundamental to increasing productivity and welfare.
Benefits for DOP Supply Chains: Welfare, Health, Sustainability
Adopting continuous environmental monitoring makes it possible to: prevent stress and diseases, reducing antibiotic use and the risk of subclinical mastitis; optimize animal welfare, acting on thermal comfort and air quality; improve metabolic efficiency through the control of digestive and manure emissions (environmental CH₄); quantify real environmental impact, supporting ESG strategies and participation in dedicated grants.
The cow’s welfare also starts from what she breathes and the environment in which she lives: an environment influenced not only by manure, eructation, genetics and feeding, but also by how the herd is managed as a whole. For example, we are talking about environmental methane and not only metabolic methane, which cannot be reduced solely to evaluations in metabolic chambers, but must be contextualized in a real farming environment.
All environmental parameters contribute to making a dairy cow a producer of excellent quality for DOP. Productivity, animal welfare and sustainability are the fundamental pillars for a unique and inimitable product such as our Parmigiano Reggiano.
Conclusion: Integrating Environmental Data into Farm Management
Continuous environmental monitoring is today a technical and strategic resource for livestock farms that wish to enhance their work in DOP supply chains. It provides objective data, enables targeted actions and allows tangible improvements to be documented.
In a context where the market increasingly demands transparency, sustainability and quality, measuring means being able to improve.
Sources
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Links
Air Quality in Barns – University of Milan
Lighting for More Milk – Dairy Producer
Effect of Photoperiod on Feed Intake and Animal Performance – Dairy Cattle Extension
