PERINATAL LAMB MORTALITY DISTRIBUTION WORLDWIDE AND CAUSES: REVIEW ARTICLE

Perinatal lamb mortality constitutes an important sanitary problem affecting sheep-farm productivity and profitability. The perinatal period is the most critical period in which mortalities can occur during the prenatal period (embryonic and fetal), the day of birth, and the postnatal period (early, intermediate, and late). The risk factors that are associated with these mortalities are related to the ewe (age, body score condition, mothering behavior, and colostrum quality), to the lamb (age, weight, sex, behavior, and body temperature at birth), and to the environment (hygiene of the livestock, climate, lambing in sheepfold or outside and the breeding system) affecting the lambs' survival and thermoregulation capacities. The global distribution of perinatal mortality varied over the years with different rates: in Africa, the reported rates were as follows: in Algeria ( 5, 8% - 17, 2%), in Morocco (14, 35%- 25, 09%), and in Ethiopia (46.3%-51.5%), On the other hand in Europe: the noted rates were of 16 % in France, (7% -10%) in United Kingdom and (25,8%) in Scotland. Moreover, in America, the rates varied from one country to another: in the United States of America (8, 2% - 17%) and Canada (14%). In Asia, the recorded rates were (17.6%- 31.3%) in India and (1, 86% - 27, 8%) in Pakistan. Also in Australia (15%-35, 8%). The causes of these lamb losses are infectious, such as pneumonia, gastrointestinal affections, septicemia, parasitism, and abortions, incriminating numerous pathogens, and non-infectious, such as starvation, dystocia, stillbirths, birth injuries, and weakness.