P.PSH.1379 - Lick-blocks for methane mitigation and production in grazing cattle

Summary

This project aimed to explore practical, effective, and cost-efficient strategies and technologies for beef cattle producers to lower methane emissions and improve productivity. This issue is particularly important in grazing regions where establishing pastures is not an option, and animals experience long dry spells with inadequate feed allowance and quality. This research will benefit grazing producers from different regions in Australia to provide supplementation in an effective manner to meet unique nutritional deficiencies. Molasses Lick Blocks (MLB) were investigated for their ability to provide methane inhibiting ingredients to cattle from varying backgrounds. The project was discontinued in 2024 after results in controlled grazing conditions did not produce statistically significant results across the mob.

Objectives

• Design feed block formulations to deliver nutritional support and CH4 mitigation options to ruminant livestock under grazing focusing on northern Australian rangeland systems (e.g., P, N supplementation, rumen modifiers).
• Determine the efficacy of the feed block system to deliver precision doses of a range of anti-methanogenic products (as a test model system to deliver powders and liquids).
• Understand the dose-response relationships of anti-methanogenic blocks in vivo and under rangeland conditions.
• Design mathematic models (e.g.: equations) for new emission reduction methodologies (dose-response models) that simplify the requirements for measuring animal performance (e.g. liveweight proxies and abatement response curves based on block consumption only).

Key findings

In vitro studies have shown a possible reduction in CH4 of up to 90% and a dose of 4–5% of the incubation fluid optimising feed degradation, volatile fatty acid concentrations, and CH4 reduction with both high- and low-quality forages.

Benefits to industry

Using lick-blocks to deliver both nutritional and anti-methanogenic supplements is a method suitable for extensive grazing environments.

Future research

Molasses lick blocks are a viable palatable, desirable, and readily available tool that should be encouraged to be utilised as a means of delivering key nutrients to cattle effectively as a supplement. However, the manufacturing process involves treatments and ingredients that may inactivate key ingredients such those investigated in the present project to reduce methane emissions. Further research is recommended to improve the stability of the ingredients during the manufacturing and storage. Supporting the development of anti-methanogenic products that are safe to animals, ecosystem and food chain for use in cattle grazing systems across Australia are keys to the future of sustainable farming and food safety.