J.R. Young, S. Stephens, V. Peenanda, S. Lestari, A.K. Umam, H. Soetanto, P.C. Thomson, P.A. Windsor
Context: Smallholder dairy farming is important for the rural economy of Indonesia, particularly in Java where over 98% of the national dairy herd is located. However, average milk yields remain below global standards due to inadequate nutrition, limited extension services, and diseases, including foot-and-mouth disease. Aims: In addressing these challenges, this study aimed to evaluate the productivity and environmental impacts of Emission Control Blocks (ECB; AgCoTech, Australia), a molasses-based nutritional supplement formulated with natural rumen modifiers, including garlic. Methods: A 15-week field trial was conducted on two smallholder farms in East Java (Malang and Tulungagung), with a total of 85 cows, including 47 cows from Farm 1 and 38 cows from Farm 2. The cows were randomly assigned to either a treatment group receiving ECB, or a control group, and measures were taken to monitor milk yield, body weight change, reproductive outcomes, and enteric methane. Key results: Compared to controls, treatment cows produced 31.9% more milk per week, gained an average of 4.9 kg more body weight over the trial duration, and had a 2.5-fold higher pregnancy rate at the trial’s end. Daily milk yield increased by 3.5 litres per cow, resulting in an estimated additional income of IDR4.55 million (USD284) per cow over a 200-day lactation period. Despite producing more total methane, treatment cows emitted 19–28% less methane per litre of milk, indicating a reduced emissions intensity. Conclusions: The garlic-based bioactive compounds in the ECB likely contributed to inhibition of methanogenesis by reducing populations of methane-producing archaea, consistent with previous findings. These findings suggest that feed-based interventions can significantly improve productivity, reproductive performance, and profitability, whilst reducing emissions intensities in the Indonesian dairy sector. However, longer-term and more widespread adoption will depend on the economic viability and accessibility of such interventions for smallholder farmers. Implications: This study supports the potential for scalable, nutrition-based strategies to contribute to Indonesia’s dairy development targets and its climate commitments under the Nationally Determined Contribution (NDC) and the Global Methane Pledge. © 2026 The Author(s) (or their employer(s)). Published by CSIRO Publishing
The University of Sydney, Sydney School of Veterinary Science, Camden, 2570, NSW, Australia; Brisbane, QLD, Australia; PRISMA, Surabaya, Indonesia; Faculty of Animal Science, Universitas Brawijaya, Jawa Timur, Indonesia
