A new study examining the carbon footprint of milk production in Bangladesh has found that using farm-specific data and more detailed emissions calculations can significantly change estimates of dairy’s environmental impact.
Researchers led by Elias Uddin, assistant professor of animal science at the University of Connecticut’s College of Agriculture, Health and Natural Resources, worked with collaborators at Bangladesh Agricultural University to assess emissions from a dairy farm over a five-year period. The research, published in the Journal of Dairy Science, examined production data from the Bangladesh Agricultural University Dairy Farm between 2018 and 2023.
The study used a life cycle assessment approach to measure emissions across the dairy production system. Researchers considered emissions from feed production, cattle digestion, manure management and farm energy use rather than relying solely on broad regional averages.
Enteric Fermentation Is the Largest Emissions Source
The analysis found that enteric fermentation was the largest contributor to the farm’s emissions, accounting for 48% of the total carbon footprint. Feed production represented another 24%, while manure management contributed 20%. Energy consumption accounted for the remaining 8%.
| Emissions Source | Share |
|---|---|
| Enteric fermentation | 48% |
| Feed production | 24% |
| Manure management | 20% |
| Farm energy | 8% |
The findings indicate that improving animal productivity and feed efficiency could have a substantial effect on emissions intensity. Since enteric emissions represent nearly half of total emissions, changes in nutrition, genetics and herd management could provide significant opportunities for reducing the footprint associated with each kilogram of milk.
Study Records a 5.18 kg Carbon Footprint
Across the five-year period, the researchers calculated an average carbon footprint of 5.18 kilograms of carbon per kilogram of milk produced at the farm.
The researchers also found an important difference between generalized and farm-specific emissions calculations. Using the IPCC’s more detailed Tier 2 methodology, which incorporates characteristics of individual animals and farm management, produced a carbon footprint 27% lower than earlier estimates based on Tier 1 calculations.
Tier 1 approaches rely more heavily on generalized emission factors, while Tier 2 methods can incorporate more detailed information about individual production systems. The findings suggest that applying generalized assumptions to developing-country dairy systems can potentially overestimate their emissions.
Productivity Emerges as a Key Factor
Milk productivity increased substantially during the study period. Average production increased from 3.53 kilograms of milk per cow per day in 2018 to 5.76 kilograms in 2023, representing a 63% increase.
The researchers linked the productivity gains to genetic selection and improved management practices, including balanced diets and more efficient feed management. Over the same period, the farm’s carbon footprint declined by 37%.
Higher productivity can reduce emissions intensity because the emissions associated with maintaining an animal are distributed across a larger quantity of milk. This makes productivity improvement an important strategy for dairy systems where average yields remain relatively low.
Dual-Purpose Cattle Complicate Carbon Accounting
Another major finding concerns the structure of Bangladesh’s livestock sector. Unlike the predominantly specialized dairy systems common in the United States, many farms in Bangladesh use cattle for both milk and meat production.
This creates challenges when allocating emissions between milk and meat. According to the study, approximately 50% of emissions on a Bangladeshi dual-purpose cattle farm are allocated to milk production, compared with around 90% in the US dairy system.
The researchers therefore suggest that evaluating emissions per unit of nutrients produced, including protein or calories supplied through both milk and meat, can provide a more meaningful comparison between different production systems.
Better Data Could Support Sustainable Dairy Growth
The study highlights the importance of farm-level data when assessing agricultural emissions. Carbon footprints can vary considerably between farms within the same region, meaning national or regional averages may conceal differences in management practices and productivity.
Detailed measurements can help identify farms with lower emissions and determine which practices could potentially be adopted elsewhere.
The findings also have implications for international dairy trade. As environmental performance becomes increasingly relevant to food markets and supply chains, accurate carbon accounting could influence how dairy products from developing countries are evaluated.
For Bangladesh and other emerging dairy markets, the research suggests that improving productivity, feed efficiency and farm management could be as important as deploying specific emissions-reduction technologies. At the same time, using appropriate accounting methods could provide a more accurate picture of the environmental performance of dual-purpose livestock systems.
