Even though pasture-animal relationships are complex farmers can modify weather-dependent seasonal impacts on their business. Based on current and possible farm management practices, research that models these complex interactions through a whole-farm systems approach are, to a certain extent, able to predict the outcomes for future climate scenarios. The model outcomes are useful for assessing the risks associated with current management practices and the soundness of the novel management options. In addition to all the bio-physical interactions impacted by climate change variables, the human factors influence exactly which farm practices and technologies are adapted. These factors include personal preferences, attitudes to risk, skills, available resources and regulatory constraints.
There are farm management options available to reduce temporary exposure to climate risks. In periods of increased pasture growth, the pasture quality needs to be maintained and there is an opportunity to increase reserves of stored feed. The options are:
speeding up the grazing rotation
shutting up paddocks and growing forage crops to make supplementary feed or provide reserves in lean times
buy in feed when supply is high and demand is low
Conversely in times of poor pasture growth rates, such as drought, the options are:
However these actions can be costly in times of drought because demand for feed is high and the availability might be limited. Issues with supply and demand become more of a problem when the drought is wide spread.
To manage a shift in seasonal timing or the intensity of more lasting climate impacts the animal stocking rate, the start and finish of lactation period, the calving date and the overall investment in feed reserves can be adjusted.
Pasture renewal tactics that include introducing deep rooted plants (such as lucerne and tall fescue) will help reduce the impact of dry soils on the pasture condition because they can assess soil water to greater depths. Also increasing the diversity of plant types (species and variety) in a seed mixture used for pasture renewal will act as a kind of insurance against more unpredictable climate extremes because there is more chance that some components of the pasture will persist.
The inclusion of perennial ryegrass and tall fescue varieties infected with novel endophyte fungus has several benefits. The novel endophyte fungus affords the grass species protection from chewing insect pests such as argentine stem weevil and black beetle. The lack of insect grazing pressure is also beneficial in times of drought stress but more importantly the toxins from some of these novel strains do not impact the health status of farm animals. Other pasture management adaptions might include increased nitrogen fertilisation to take advantage of increased CO2 concentrations
There are other significant changes to farm infrastructure which help manage the impacts of climate change:
Shelter and shade for dairy cows will be essential to manage heat stress associated with temperature increase or the effects of more extreme storm events
Installation of irrigation systems and water storage schemes will help manage summer soil moisture deficits
Adaptations for managing the impact of a hotter climate include:
New production systems are the least well defined and degree of investment or the time lags before the benefits are realised are not well understood.
Improved genetics and breeding that selects for drought adaptations in both plant and animal species are promising.