Problems with the use of ear tags in sheep.. [Correspondence]

agneau animal welfare application methods bacteriose bacterioses bacteriosis bienestar animal brebis cordero ear diseases ear tags ewes flora microbiana flore microbienne heridas identification lambs maladie de l'appareil auditif metal metales metals microbial flora oveja ovin ovinos pathogenese pathogenesis plaie sheep tetraciclina tetracyclines wounds