New study examines reduction of bovine methane through animal husbandry
Adding a negative economic value for methane could facilitate a substantial reduction in methane emissions while maintaining an increase in milk production, according to a new international study on dairy cows and animal husbandry.
The study, published in recent days on the Journal of Dairy Science, stressed that the selection of cows emitting less methane is “one of the best approaches to reduce methane”, given that “genetic progress is permanent and cumulative over generations”.
The research report – titled “Livestock for Methane Reduction and Feed-Efficient Holstein Cows: An International Response” – was written by a selection of authors from around the world, including Denmark, Australia, Canada and Switzerland.
According to the study, data from different countries could be combined to accelerate the development of “precise genetic parameters for methane traits” – and form a future genomic reference population.
Among its stated goals, the report sought to estimate “the genetic parameters of seven suggested methane traits as well as the genetic correlations between methane traits and production, maintenance and efficiency traits using a baseline multi-country data ”.
Across the authors’ four countries, the study examined 15,320 records of methane production from 2,990 cows.
A number of characteristics were examined, in particular the ingestion of dry matter; body condition score; various body weight measurements; milk production; methane yield; methane intensity; “Standardized production of methane; residual food intake; “Energy-corrected milk”; and three definitions of residual methane production.
Of these, according to the report, the breeding index calculations showed that residual methane had the greatest potential for inclusion in the breeding target when compared to methane production, methane yield and to the intensity of methane.
This, say the authors, is because “residual methane allows selection of animals with low methane emissions without compromising other economically important characteristics.”
“Residual methane” in research has been defined as “residue from the partial regression of methane production on MBW [metabolic body weight] and DMI [dry matter intake]”.
Other definitions used included “the residual of the partial regression on MBW and ECM [energy corrected milk]”And” the residual of the partial regression on MBW, DMI and ECM, with fixed effects “.
In addition, the report states:
“Inclusion of residual dietary intake in the breeding objective could further reduce methane, as the correlation with residual methane is moderate and elicits a favorable correlated response.
“Adding a negative economic value for methane could facilitate a substantial reduction in methane emissions while maintaining an increase in milk production,” the international study noted.