The Survival Analysis of the Potential Risk Factors Affecting Lamb Mortality in Deccani Sheep

Abstract

The lamb mortality is critical component in sheep industry. The present study was carried out to determine the lamb mortality and its associated factors in Deccani sheep using survival analysis. The data records of 2168 lambs reared at ICAR-Network Project on Sheep Improvement, MPKV, Rahuri (India) were obtained from inventory and death registers for the period of January 2005 to December 2015. The survival analysis of lamb mortality using Cox proportional hazard model was undertaken to determine the potential risk factors affecting lamb mortality in the study. All statistical analyses were done using R 3.1.0 Software. The overall lamb mortality for birth to 1 month age, birth to weaning age and birth to 1 year age was 2.21%, 4.70% and 10.10%, respectively. It was found that lambs with low birth weight had greater risk of mortality than heavier lambs at birth. Male lambs were at higher hazards of mortality than female lambs. Furthermore, higher risk of mortality was observed in rainy season as compared to other seasons. In order to reduce the economic losses due to lamb mortality, implementation of improved farm practices according to seasonal variation, flock structures (pregnant ewes, newly born lambs etc.) is suggested.