Samkange, AlasterMushonga, BordenKandiwa, ErickKambode, Josephina NdamonakoMbiri, PricillaGorejena, BrightonMadzingira, Oscar2020-09-242020-09-242020Samkange, A. et al. (2020). Assessment of normal mortalities, biosecurity and welfare of lohmann brown layers at a farm in central Namibia. International Journal of Poultry Science, 1-10.http://hdl.handle.net/11070/2875Objective: The current study investigated the causes of mortality and evaluated the biosecurity situation and welfare conditions of Lohmann Brown layer chickens reared for 12 months, from point-of-lay, at farm A in central Namibia. Materials and Methods: Necropsies, standard biosecurity appraisal and on-farm welfare assessment tools were used. A standard protocol was used for post-mortem examinations of dead birds. The Chi-square test was used for analysis of causes of mortality whilst linear regression was used for analysis of the temporal distribution of mortality. Results: The overall mortality rate throughout the study period was 18.7% (N = 1000). There was a very strong negative correlation between duration of birds in lay and proportion of live birds [r (162) = 0.97, p<0.05]. The proportion of live birds decreased by an average of 2.98% for every 50 days of the laying period. Overall, the proportional mortalities due to undetermined causes (31.6%) were greater than those due to inflammatory conditions, trauma, cannibalism and retained eggs (20.9,19.3,16.6 and 11.8% respectively, p<0.05). Conclusion: The high mortality rates reported in this study have an obvious negative impact on productivity and thus there is a need to improve the biosecurity and welfare conditions for these layers in order to improve profitability.enLohmann brown layersLayer mortalityBiosecurityArticle