Genetic Improvement as Adaptation Option for Climate Change in Dairy Farms in South Eastern Australia.

The dairy industry has to increase production while overcoming the effects of climate change. This project assessed these challenges by adopting genetic advancements in dairy farms in order to adapt the systems to climate change. Historical and prospected climate scenarios were simulated by using daily climate data from the SILO meteorology database. The different handling styles and climate fluctuations of two farms were simulated using DairyMod. Using current pasture species and livestock, it first was modelled the effects of climate change in 2050 and 2080 on pasture growth, feed consumption, and milk production. Afterward, it was modelled better adapted pastures (deeply rooted, or "DR" and heat-tolerant, or "HR"), as well as livestock (with higher feed conversion efficiency, or "FCE"). The growth patterns of pastures will be impacted by climate change as the spring growing season will be shorter. Climate change will also result in less milk production and less feed consumption. The combined adapted perennial ryegrass DR+HT is the most effective adaptation alternative to counteract the effects of climate change on pasture growth. The combined adapted perennial ryegrass DR+HT and the multiple adaptations FCE+DR+HT are the most effective ways to counteract the effects on overall feed consumption. The best adaptation strategy to combat the decline in milk production is to use the multiple adaptations FCE+DR+HT. The use of genetically modified dairy cattle with ryegrass can increase milk supply by up to 5% until 2050. These findings suggest that genetically modified dairy cattle and genetically modified ryegrass must be introduced together in order to adapt a dairy system. [ABSTRACT FROM AUTHOR]