Survival Analysis For Children Weight Lines Of Japanese Quails Using Cox Model
1865 WordsSep 29, 20168 Pages
Survival Analysis for Evaluation of Mortality in Selected Body Weight Lines of Japanese quails Using Cox Model
Quail rising has become an important poultry business in the world.
The objective of this study was to carry out survival analysis to evaluate and quantify risk factors involved in mortality of Japanese quail. Survival analysis and Cox proportional hazards model were used to describe mortality in Japanese quail with hatch weight and post hatch body weight as a risk factors. Weight is a variable change with time, so it is considered time dependent covariate.
Survival function distribution and Kaplain Meier curve showed that mortality was higher in the line selected for high compared to low and control line. Log rank test used for testing equality of survival distributions for the different levels of selected lines (Log-Rank value = 9.898) resulted P value = 0.007** which is a highly significant.
Mortality declined when post hatch body weight increased. Body weight at hatch did not significantly affect mortality. However, post hatch body weight affects mortality significantly with P- value (0.011) and hazard ratio (1.009). Any factor that inﬂuences growth after hatching may likely have a direct impact on mortality. Deficiency of water, feed, warmth, and potential negative social interaction are factors that could affect mortality immediately after hatch. Through survival analysis, the present study has revealed that factors affecting post hatch BW