Assessment of normal mortalities, biosecurity and welfare of Lohmann Brown layers at a farm in central Namibia

Abstract
Objective: 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.
Description
Keywords
Lohmann brown layers, Layer mortality, Biosecurity
Citation
Samkange, 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.