Effect of ectoparasites on quality of pickled skins and their impact on the tanning industries in Amhara regional state, Ethiopia

Five groups of 20 infested skins with different ectoparasites and different levels of infestation and two groups of negative control skins from sheep and goats were examined for their corresponding defects at the pickled or wet blue stage of processing in tanneries. In addition, an analysis of skin defects was made from randomly selected processed skins at Kombolcha and Dessei tanneries. The prevalence of ‘ekek’ (cockle) at the pickled stage in Damalina ovis and Melophagus ovinus-infested sheep skins were 100 and 95%, respectively. Pickled goat skins affected by sarcoptic mange and Linognathus spp. were 100 and 0% positive for ‘ekek’ (cockle) lesion, respectively. The prevalence in control sheep and goat skins were 15 and 0%, respectively. There was a strong association (p < 0.05) between ‘ekek’ and infestation with M. ovinus and D. ovis in sheep and sarcoptic mange in goats. Follow-up of randomly selected 1000 pickled sheep skins and 1000 wet blue goat skins revealed that 71% of pickled sheep and 42% of wet blue goat skins had ‘ekek’ lesions. As the proportion of ‘ekek’ increased, the quality of graded skins decreased both in sheep and goats. Both on pickled sheep and wet blue goat skins, scratch and scars were found to have a strong association (p < 0.05) with ‘ekek’. The annual economic loses in 2002/2003 due to ‘ekek’ at the two tanneries was estimated to be 1.6 million USD for pickled sheep and 0.6 million USD for wet blue goat skins.