D. O'Brien

TL;DR: A review of 31 published whole farm modelling studies of GHG emissions from beef and dairy cattle production systems indicated a number of important outcomes as mentioned in this paper, such as improvements in animal productivity (i.e., liveweight gain milk production), lower culling, lower replacement rates, and intensification of production as output/ha can reduce emissions/kg product.

TL;DR: In this article, the authors developed an LCA model to compare contrasting milk production systems, a seasonal pasture-based dairy farm and a confinement dairy farm, and found that when expressed per unit of milk and per on-farm area, all total environmental impacts were greater for the confinement system compared to the grass-based system.

TL;DR: Compared to recent reports that assess the carbon footprint of milk from average Irish, UK, and US dairy systems, this case study indicates that top-performing herds of the respective nations have carbon footprints 27 to 32% lower than average dairy systems.

TL;DR: The results showed that as cow strain changed from lower (HD and NZ) to higher genetic potential (HP) for milk production, the GHG emission per kilogram of milk solids increased, and this was associated with increases in herd total feed intake.

TL;DR: Partial least squares regression analysis of correlations between financial and environmental performance indicated that extending the length of the grazing season and increasing milk production per hectare or per cow reduced the CF of milk and increased farm profit, however, where higher milk productionper hectare was associated with greater concentrate feeding, this adversely affected the CF and economic performance.