Brainstem Auditory Evoked Potentials in Japanese Black and Holstein Cattle

Abstract

ABSTRACT. This study was performed to examine normal brainstem auditory evoked potential (BAEP) data for adult Japanese Black cattle and to evaluate whether differences exist in the peak latencies, interpeak latencies (IPL) and waveforms of BAEP between Japanese Black and Holstein cattle. The peaks were detected as major waves I, II, III and V in each group. The threshold of the BAEP waves in the Holstein cattle was 65-75 dB nHL, but the threshold in the Japanese Black cattle was 75-85 dB nHL. The I-III and I-V IPLs were significantly shorter in the Japanese Black compared with the Holstein cattle at an intensity of 105 dB nHL. The present findings suggest that the IPL and wave threshold of BAEP are influenced by bovine breed. KEY WORDS: BAEP, cattle, Holstein, Japanese Black.J. Vet. Med. Sci. 70(10): 1139-1142, 2008 Brainstem auditory evoked potentials (BAEP) are bioelectric waves consisting of a sequence of 4 to 7 peaks in the potential, which can be recorded from scalp electrodes within the first 10 msec after an auditory stimulus [13]. Each electric potential is generated by activation of one of the subcortical components of the acoustic pathway. Measurement of BAEP is useful in objective assessment of auditory function and of the localization of brainstem lesions in humans [3]. In the BAEP of Holstein cattle, vertex-positive peaks have been identified as waves I, II, III and V, while wave IV is usually absent [2,15]. The generator site of wave I of the BAEP is thought to be the eighth nerve, and wave II is possibly generated by the cochlear nucleus [3]. The generator sites of waves III and V are thought to be the superior olivary complex of the obex and the inferior colliculus of the midbrain, respectively [3].The peak and interpeak latencies of BAEP have very good reproducibility. On the other hand, it has been reported that the peak or interpeak latencies of BAEP are influenced by physiological factors such as age, gender, size and breed. In humans, the peak latencies of BAEP are longer in men than in women [14], and there are increases in the peak latencies of BAEP waves with increasing age after childhood [12]. In dogs and horses, it has been reported that the peak or interpeak latencies of BAEP depend on size and breed [9,11]. The purpose of this study was to examine normal BAEP data for adult Japanese Black cattle and to evaluate whether differences existed in peak latencies, interpeak latencies (IPL) and the waveforms of BAEP between Japanese Black cattle and Holstein cattle.Ten adult Japanese Black cows 2 to 12 years of age and 10 adult Holstein cows 2 to 6 years of age were used in the present experiment. Japanese Black cattle were housed at the Hokkaido Animal Research Center and Holstein cattle were housed at the National Institute of Animal Health. The animals were given a commercial cattle concentrate, hay and free access to water; silage was also given to Japanese Black cattle. All animals were healthy and appeared to have normal audition based on their responses to environmental sound stimuli...

Regular Exposure to Cowbells Affects the Behavioral Reactivity to a Noise Stimulus in Dairy Cows

“…BAEP are bioelectric waves that can be recorded within 10 ms after an auditory stimulus and are used to assess auditory function ( 65 ). Due to the influence of excessive muscle movements on the measurement, it is necessary for the subject to be motionless during the procedure ( 37 ). Clinically, therefore, sedation is needed when measuring BAEP in young children or animals.…”