Rumen Stability identifies and exploits long-term effects of short-duration dietary treatments on methane production, rumen function and responses to methane mitigation interventions at a later stage.
There is a focus on manipulations in early life, when the rumen community is developing, but also work on other diet transitions. The idea is to reduce the cost and effort of mitigation strategies by reducing the duration and/or quantity of treatment required and/or to increase the size of responses if treatments have to be reapplied.
Whilst earlier studies with young ruminants have used potent anti-methanogenic compounds, this work focuses on the residual effects of some of the dramatic diet transitions experienced on-farm, including weaning and transitions to grazing or high-density finishing diets.
This project addresses effects of management history on the interaction between the host and its microbiome and on methane production. The ability to identify differences between animals makes the work highly complementary to existing programs on the effects of host genetics/genomics on methane production.
Studies with calves and goat kids in Belgium showed increasing methane emissions intensity over rearing. Unexpectedly, it was more difficult to reduce emissions in young ruminants.
Studies in Ireland showed: (i) colonisation of calves from surroundings or maternal sources, (ii) the rumen microbiome settles by week 3, (iii) gene expression in rumen tissue is affected by age and diet, (iv) mechanisms governing nutrient absorption, tissue development, and immune-microbe interactions are all enriched following birth.
Studies in New Zealand and France with lambs and calves showed that early-life dietary intervention modulated microbes, with small changes persisting. Studies with lambs suggested that dietary intervention in early life may yield more persistent changes in rumen microbial communities than using the same strategies in mature animals.
In German studies, methane yield of calves tended to increase with a higher intensity of milk replacer feeding, but this effect did not persist. Other work looked at the effects and susceptibility to manipulation of the microbiome of older ruminants. The role of microbial species in determining feed efficiency was identified. Studies in Germany showed that methane production from dairy cows was highest in late lactation and methane yield in early lactation decreases with increasing fat mobilisation.
*At the time of the proposal. Please consider this data as an accurate estimate; it may vary during the project’s lifespan.
Total costs include in kind contribution by grant holders and can therefore be higher than the total requested funding.