A new multi-institutional study has found that climate-smart feeding strategies—particularly feedlot systems using locally available concentrate feeds—could significantly increase beef production in Tanzania while sharply reducing methane emissions.
The research, conducted by scientists from the International Livestock Research Institute (ILRI), Tanzania’s Ministry of Livestock and Fisheries, Sokoine University of Agriculture, and Aarhus University, provides a compelling pathway for aligning livestock productivity with climate goals in one of Africa’s largest cattle-producing countries.
The study, titled Animal Performance and Methane Emissions in Feedlot vs. Traditional Pastoral Systems with Concentrate Supplementation for Tanzanian Short Horn Zebu and Boran Cattle, evaluated how different feeding regimes influenced growth performance and enteric methane emissions in two common cattle breeds: the indigenous Tanzanian Short Horn Zebu (TSHZ) and Boran cattle.
Feedlot systems outperform traditional grazing
The experiment was carried out over 100 days at Kongwa Ranch in central Tanzania. A total of 120 steers—60 Boran and 60 TSHZ—were assigned to one of five dietary treatments: grazing only; grazing supplemented with 50% concentrate; and three hay-based feedlot diets supplemented with 60%, 80%, or 100% concentrate.
Methane emissions were estimated using the 2019 Intergovernmental Panel on Climate Change (IPCC) guidelines, allowing researchers to calculate emission intensity measured as grams of methane produced per kilogram of weight gain.
Results showed that concentrate supplementation increased average daily weight gain (ADG) by between 6% and 33%, depending on diet and breed. At the same time, daily methane emissions declined by 3% to 35% compared to grazing-only systems.
The most dramatic improvements were recorded under full feedlot conditions. Cattle fed a 100% concentrate diet produced the lowest methane intensity, with emissions dropping from approximately 396 g CH₄ per kilogram of weight gain under grazing-only conditions to just 87 g CH₄ per kilogram.
Productivity gains offset breed differences
While Boran cattle emitted slightly more methane per animal per day than TSHZ cattle—largely due to their larger size and higher feed intake—they also gained weight faster. As a result, methane emissions per kilogram of beef produced were broadly similar between the two breeds.
Overall, the shift from traditional grazing to concentrate-supplemented feedlot systems reduced total daily methane emissions by 28–65% and lowered methane intensity per kilogram of meat by nearly 80%.
A practical solution for Tanzania’s beef sector
Tanzania has one of Africa’s largest cattle populations, yet productivity remains constrained by traditional pastoral systems that rely on seasonal, low-quality forage. These systems tend to produce beef slowly while generating higher greenhouse gas emissions per unit of output.
With domestic beef demand rising due to population growth and increasing incomes, the study highlights improved feeding as a practical “low-hanging fruit” for boosting output without expanding land use or emissions.
The researchers note that locally sourced feed ingredients—including maize meal, cottonseed cake, molasses, mineral mixes, salt, and urea—make feedlot systems more economically viable for small- and medium-scale producers.
“Improved feeding systems are powerful levers for both productivity and climate mitigation,” the authors conclude. Faster weight gain means cattle reach market size sooner, reducing the total time they emit methane and delivering more beef per unit of emissions.
Next steps
The study’s authors caution that scaling up feedlot systems will require reliable access to feed inputs and well-functioning supply chains, particularly for crop by-products. Future research will test the findings under real-world farm conditions and involve direct methane measurement, using individual-animal sensors and drone-based monitoring systems developed by ILRI.
