Aversion to bromadiolone in the presence of an alternative food, in wild house mice (Mus musculus) captured on poultry farms

ARISTEGUI, E.; MIÑO, M.; MANSILLA, P.; CUETO, G. R.; GUIDOBONO, J. S.; BUSCH, M.

Mendoza, Argentina

Congreso; 10 th International Mammalogical Congreso; 2009

International Federation of Mammalogists - IFM and Sociedad Argentina para el Estudio de los Mamíferos - SAREM

This study tests the hypothesis that populations of Mus musculus (Rodentia, Muridae) present on poultry farms applying bromadiolone as rodenticide have aversion to bromadiolone. The hypothesis was tested by a two-choice trial carried out on 60 mice captured on poultry farms in the County of Exaltación de la Cruz (Buenos Aires province, Argentina). Mice were mantained in individual cages under laboratory conditions and, after a minimum of 7-days acclimatisation, were randomlly divided into three groups, consisting of 10 females and 10 males, that daily recieved the following feeding treatments: (group B) 6g of bromadiolone; (group T) 6g of wheat grains and (group BT) 6g of bromadiolone and 6g of wheat grains. During a 10-days period, all remanent of the offered food was daily collected and weighed to estimate daily consumption. Food preference-rejection was estimated in group BT using the Ivlev’s Electivity Index, while the curves of consumption of bromadiolone were compared between groups B and BT. Moreover, the cumulative consumption of bromadiolone and the cumulative total consumption were also compared between those groups and sexes using ANOVA (when possible) or Kruskal-Wallis test. The Ivlev’s Index indicated that both sexes reject bromadionone. Group B showed curves of consumption of bromadiolone with a final increse, consistent with a change in the food election, while group BT showed curves of consumption of bromadiolone that decline to the end. The cumulative consumption of bromadiolone resulted lower in group BT than in group B, while there were not differences in the total consumption between groups, indicating that group BT compensated its total consumption by eating wheat grains. We conclude populations of M. musculus present on poultry farms have aversion to bromadiolone in presence of wheat grains as alternative food. As food for chickens contained wheat, we suggest bromadiolone should be applied in the breeding midtime.