On March 2, over 50 participants attended a Feed4Foodure Study Afternoon on the project ‘Low Emission Livestock Feed’ in Wageningen, the Netherlands. Researchers of Wageningen UR presented recent findings on mitigating enteric methane production of dairy cattle. Results of the project clearly demonstrate significant possibilities for dairy farmers to reduce methane emissions. The presentations are available from the Feed4Foodure website.
Dr André Bannink outlined the Innovation Programme Low Emission Feed. The 5-yr programme is funded by the Dutch Ministry of Economic Affairs, the Product Board Animal Feed, and the Dutch Dairy Board, and started in 2011. The programme aims to contribute to achieve a 30% reduction of greenhouse gas emissions in 2020 compared with 1990. It comprises experimental and modelling research as well as implementation at dairy farms.
Dr Jan Dijkstra presented the results of three extensive experiments using the Wageningen climate respiration chambers, investigating effects of grass and grass silage management on methane production. He concluded that the key to methane reduction is high quality grass and grass silage. Grass grazed or harvested for ensiling at an early, leafy stage significantly reduces methane emission intensity per unit milk compared with more mature grass. Differences between methane emission intensity of young, leafy grass silage compared with mature, stemmy grass silage are more than 30%.
In contrast with harvesting grass at an early stage, Dr André Bannink showed that increasing maturity of whole plant maize at harvest decreases methane losses with feeding maize silage without negatively affecting cow performance up to 40% DM in whole plant maize. An increased maturity of maize increases its starch content and reduces rumen starch degradability, both giving rise to lower methane production. This strategy may reduce methane emission intensity of maize silage by up to 10%.
Several feed additives are applied to reduce methane production, but rumen microbes may adapt to these additives and the methane mitigating effect may be lost after some time. Geronda Klop presented results on adaptation to additives, with a view on how to employ alternating use of two or more methane reducing feed additives with a different mode of action to alleviate the problem of microbial adaptation in the rumen. The first step, in vitro screening, indicated several promising additives. In the second step, it was shown that the length of adaptation period of cows affected methane production in vitro. At present, the alternating use of feed additives on methane production in dairy cattle is being investigated.
Last but not least, Dr Léon Šebek presented results of mitigations options in practice. Nitrate was evaluated for well over a year on the applied dairy farm De Marke, with positive and encouraging results. Furthermore, the experiences and opinions of several farmers of the ‘Cows and Opportunities’ project on methane mitigating measures were presented. In practice, several possibilities to reduce methane production can be rather easily implemented. Other possibilities remain a challenge to be implemented because of the high level of management skills required. Dairy farmers indicate the problem of potential trade-offs with other environmental pollutants, and the uniform presentation of practical indicators remains a major undertaking.
The presentations are available from the Feed4Foodure website.