0 avis
A framework to study the resilience of dairy herds to climate change from on-farm data
Archive ouverte
Edité par CCSD -
International audience. Climate change is known to challenge mountain livestock farming systems through its impact on forage resources availability. However, information about their vulnerability to heat waves is meager. Previous studies showed that heat waves can severely affect dairy cows’ welfare and activity, their reproductive success and milk yield. Thus, the ability of mountain dairy herds to cope with heat episodes is worth to be addressed. The objective is to develop a framework to examine the resilience of dairy herds to heat waves from milk data gathered on farms.The study was carried out on 1500 dairy herds located in a mountain area (Puy de Dôme, France), covering a period of 22 years. Longitudinal data available for each herd concerned productive (milk yield) and reproductive (calving to calving interval) performances along with cows longevity. Weather data (daily temperatures and humidity) for the same period and area , were used to calculate the daily temperature humidity index (THI) at a local scale. Heat stress events (HSE) were identified when THI was both higher than 68 and higher than weekly average for at least three consecutive days. Finally, yearly cumulative sums for both duration and levels of HSE were calculated. Dairy herd resilience was assessed through the ability of a given herd to maintain yearly performances relatively stable when experiencing HSE (being minimally affected or going back rapidly to equilibrium state). Then, resilient and non-resilient dairy herds were contrasted in terms of their characteristics (milk yield, breeds, calvings and lactations distribution).The development of such a framework may be useful to identify levers of resilience at the herd level that would ultimately help dairy farmers better dealing with the expected increase in frequency and intensity of HSE.
Consulter en ligne
Suggestions
Du même auteur
