Epidemiological Analysis of Sheep Mortality under Temperate Conditions in a Closed Nucleus Flock
R. Prabhakar *
Sheep Breeding Research Station, Sandynallah, The Nilgiris, India.
N. Prema
Veterinary College and Research Institute, Tirunelveli - 627 358, India.
R. Anil Kumar
Madras Veterinary College Campus, Chennai - 600 007, India.
*Author to whom correspondence should be addressed.
Abstract
Understanding epidemiological risk factors is absolutely crucial for minimizing livestock mortality, particularly in sheep farming. A comprehensive study analyzed a decade of data from the Sheep Breeding Research Station, Sandynallah, The Nilgiris, Tamil Nadu, to definitively assess the influence of factors such as age, breed, sex, lambing period, season, weaning period, fecundity and weather parameters on sheep mortality.
The results unequivocally showed that 58.6% of the deaths occurred in young sheep, while a staggering 60.7% of the overall mortality was in females. The main lambing period exhibited a significantly higher birth rate and was responsible for a striking 84.8% of the deaths. Notably, summer months accounted for a substantial 49.3% of all mortalities, the highest among all seasons. Pre-weaning lambs experienced an alarming 74.82% of the deaths, compared to a mere 25.18% in the post-weaning period. Furthermore, weather parameters, especially summer and rainfall, were unequivocally established as major contributors to the mortality.
In conclusion, this study conclusively found that sheep mortality in a closed nucleus flock was undeniably linked to epidemiological risk factors including young age, female sex, lambing period, summer season, weaning stage and environmental factors like temperature, humidity, wind speed, frost, and rainfall. These findings provide indisputable insights for reducing mortality in similar sheep farming environments.
Keywords: Sheep, lamb, mortality, risk factors, climatic factors