Dear Mark,
 
Finally, the animal trial is completed and I have some free time. I am sorry for the late response.
 
A mathematic model of methane emission model is being developed by Min WANG, a talented scientist at the Institute of Subtropical Agriculture, Chinese Academy of Sciences, China. This model can separate basal methane emissions largely resulting from the slowly degraded fraction of diet and feeding methane emissions mainly resulting from the fast degradable fraction. The ratio of basal methane emissions and feeding methane emissions might be manipulated and thus total emissions could be reduced. This model also can describe daily change of methane emissions. He used their data obtained from lactating dairy cows and found that 70% of total methane emissions were from the basal emissions. A manuscript has been submitted and is under review now.
 
I have been involved in the development of the mathematic model. I am thinking to use the model to our published data to see the ratio of two parts of emissions from sheep fed chicory and brassicas in comparison with pasture. Our animals were sheep and the diets were forage. Their animals were lactating dairy cows and the diets were concentrates and roughage. My feeling is that the model developed from their animals and diets may not be suitable to us. Anyway, it is worthy to have a try.
 
The model could be improved once we have time course data of feed intake. I should be able to get such data when I measure methane emissions from cattle. If we can establish a relationship between instantaneous feed intake and instantaneous methane emissions from these data, then we can stimulate methane emissions from grazing animals. If this is the case, the study has a strategic value.
 
It is too early to judge its strategic value. We need to get instantaneous feed intake data and to link these data with instantaneous methane emission data first.
 
This modelling approach is different from the hydrogen/methanogen model that is under way in New Zealand. It is a complementary approach to what David and Peter are working on. Ultimately some of the prediction from Mr Wang’s model could be further explored in terms of the detailed effects on rate of passage and hydrogen/methanogen interactions being developed in New Zealand. This will create some synergies in terms of further understanding mechanisms of methane production.

Best regards,
 
Sunny
