On 12 April 2021, Maximin Bonnet defended his thesis "Vulnerability and food autonomy of island areas: a demographic scenario approach to assess the dynamics of the suckler cattle population in Réunion". A long but successful work!


Cattle herd in Réunion Island © M. Deresse, CIRAD

 In short :

"This thesis proposes both an economic and zootechnical approach to suckler farming in Reunion Island. Despite strong political incentives for its development, the role of this sector in rural development is now being questioned. In order to respond to these controversies, we conducted a study on the contribution of the beef sector to the reduction of structural economic vulnerability.
To do this, we first showed that food dependence is an important factor of vulnerability for small island areas. We used a composite vulnerability index constructed using an endogenous weighting method for robustness purposes.
Secondly, we sought to identify the agricultural sectors most likely to reduce Réunion's food dependency. The suckling cattle sector appeared to be the most promising because of its strong structure, its capacity to valorise local resources and the possibility of gaining market shares in a logic of import substitution.
We then conducted a study of the determinants of the past dynamics of the beef sector in Réunion. We have shown that this production is mainly driven by economic factors which, through the decisions of farmers, have led to a deterioration in the zootechnical performance of animals. We have also shown how the cooperative's reaction to this situation has enabled the growth of the herd and production to be revived.
We then looked at the parameters influencing the productivity of the Reunionese suckler herd by constructing and analysing a demographic model. Our results showed that reproductive and growth performance are the most important factors in increasing productivity. Based on these elements, we built evolution scenarios in close collaboration with the cooperative. In particular, these scenarios integrated elements on the improvement of animal performance, changes in farmers' practices and changes in the organisation of production at the cooperative level. We have shown that performance improvement, herd rejuvenation, the introduction of sexed artificial insemination and grass-fattening are means of developing the Reunionese suckling sector.
Our thesis provides arguments for reconsidering the role of agriculture in the structural economic vulnerability of Réunion and demonstrates the interest of developing the suckler farming sector to reduce this vulnerability. It also presents ideas for decision-makers and stakeholders in the field with a view to increasing beef production in Réunion. It constitutes an in-depth study of the reasons for and means of developing the suckling beef sector on the scale of a tropical island territory."

Maximin Bonnet