RESILIENCE OF THE DAIRY CATTLE HERD STRUCTURE TO LIGHTNING ACCIDENTS

Abstract

Climate change is producing an increase in the frequency of lightning strikes and the risk of accidents with animals in rural areas. The animals’ death by fulmination causes herd’s structure destabilization, generating handling inefficiencies and economic losses. Avoiding the exposure of animals to lightning accidents is an action to build climate resilience of dairy cattle that improves the ethical standard of livestock. The operationalization of resilience as an attribute of the dairy cattle production system generates information that guides the adoption of sustainable technology and the management of herds affected by disturbances caused by lightning disturbances. The System Dynamics methodology was used to simulate scenarios quantifying the resilience of the herd structure to lightning disturbances. In the mild scenario with lightning disturbance of magnitude equal to 0.10, 10 lactating cows died, out of a total of 186.25 animal units (AU) and ten cows, four calves and five heifers were no longer discarded with a delay of two years to stabilize the herd’s structure. In the severe scenario, a lightning disturbance with a magnitude of 0.17, which resulted in the death of 17 lactating cows, there was a loss of 11.75 AU. For a disturbance with magnitude equal to or above 0.18, the system did not recover the stability of the structure of the initial herd before the lightning accident. Losing resilience in this magnitude is worrying considering the possibility of dairy cattle fulmination in the order of up to 50%, magnitude of 0.50, of the animals on the farm in a single event. The in silico experiments with simulation of the Herd model generated scenarios with counterintuitive behaviors of the herd structure resilience, which promote learning and are useful for the management of pasture-based dairy cattle system.