ObjectiveTostudytheauditionandinnerearstructureinanormalswinemodel.MethodsAuditorybrainstemresponses(ABRs)weredeterminedinswineat1dayand1monthafterbirth.Theformofthecochleaandhaircellswereexaminedunderascanningelectronmicroscopeandoncochlearslices.ResultsABRthresholdsat1dayand1monthpost-birthwerebetween40and50dBSPL.ThelatenciesofwavesI,IIIandVin1dayoldswinewere1.97±0.13,3.01±0.16and4.26±0.20ms,respectively.At1month,thelantanciesofwavesI,IIIandVwere2.01±0.05,3.11±0.08and4.65±0.14ms,respectively,slightlylongerthanthoseat1day,althoughnotstatisticallysignificant(p>0.05).Theswinecochleawasconstitutedof3andahalfturnsandthecochlearhaircellslinedupinfourrows.Haircellciliaintheapicalturnwerelongerthanthoseinotherturns.ConclusionsTheswinecochleaismatureatthetimeofbirth.SwineABRthresholdsareslightlyhigherthanhumansandrats.Swineappearstobeaprecocialanimalspecies.
