A new multi-institutional study has shown that combining locally formulated concentrate feeds with feedlot management can substantially increase beef production while sharply reducing methane emissions in Tanzania.
The findings provide fresh evidence that improved feeding systems could play a central role in shaping a more climate-smart livestock sector.
The research — conducted by the International Livestock Research Institute (ILRI), Tanzania’s Ministry of Livestock and Fisheries, Sokoine University of Agriculture, and Aarhus University — charts a practical pathway for boosting productivity and lowering emissions at scale.
The Animal Performance and Methane Emissions in Feedlot vs. Traditional Pastoral Systems with Concentrate Supplementation for Tanzanian Short Horn Zebu and Boran cattle study examined how different feeding regimes influenced growth performance and enteric methane output in two commonly kept cattle breeds — the indigenous Tanzanian Short Horn Zebu (TSHZ) and the larger-framed Boran.
The experiment, carried out at Kongwa Ranch in central Tanzania, assigned 60 Boran and 60 TSHZ steers to one of five dietary regimes for 100 days: grazing only; grazing plus 50% concentrate; and three ad libitum hay-based diets supplemented with 60%, 80%, or 100% concentrate.
Methane emissions were estimated using the 2019 revision of the Intergovernmental Panel on Climate Change (IPCC) guidelines and used to calculate emission intensity — grams of methane per kilogram of weight gain.
The results were compelling. Concentrate supplementation raised average daily weight gain (ADG) by roughly 6% to 33% depending on diet and breed, while daily methane production fell by 3% to 35% compared to cattle on grazing-only systems.
Among the treatments, the highest concentrate diet (100% concentrate, no grazing) delivered the lowest emission intensity: methane emissions per kg of weight gained dropped from about 396 g CH₄/kg for grazing-only animals to just 87 g CH₄/kg under full concentrate feedlot conditions.
On a per-animal per-day basis, breed differences were modest — Boran cattle emitted slightly more methane per day than TSHZ, likely due to their larger size and higher feed intake (127 vs. 114 g CH₄/day). But because Boran steers also gained weight faster (738 vs. 626 g/day), the methane emitted per kilogram of meat produced ultimately balanced out.
Overall, shifting from traditional grazing to feedlot systems supplemented with locally sourced concentrates reduced total methane emissions per day by 28–65% and cut methane intensity (per kg of meat) by nearly 80%.
The implications are significant. Tanzania has one of Africa’s largest cattle herds, yet traditional pastoral systems — dependent on seasonal, low-quality forage — produce slow-growing animals that generate higher greenhouse gas emissions per kilogram of meat. With domestic beef demand rising due to population growth and higher incomes, the need to produce more meat from existing land while containing emissions is becoming urgent.
By demonstrating that feedlotting with affordable, readily available feeds (such as maize meal, cottonseed cake, molasses, mineral mix, salt and urea) can deliver faster growth and dramatically lower methane intensity, the study points to an accessible “low-hanging fruit” for producers and policymakers.
According to the authors, improved feeding is not just about boosting weight gain — it is a “powerful lever for both productivity and climate goals.” Faster growth shortens the number of days an animal spends emitting methane before reaching market weight, increasing beef output per unit of emissions.
However, the researchers emphasize that scaling up feedlot systems will require dependable access to feed inputs — particularly crop by-products — along with careful attention to costs and supply chains.
Looking ahead, the research team plans to validate the results under real-world farming conditions. Upcoming work will use direct methane-measurement technologies — including individual-animal methane sensors and drone-based group-level monitoring developed at ILRI — to test how closely the IPCC-based estimates match actual field emissions.
