Causes of Lamb Mortality in the Lacaune Sheep Breed in Iran

  Neonatal mortality is a significant multifactorial problem that affects flock productivity. Different infectious and non-infectious factors have been attributed to lamb losses. The objective of the present study was to identify the major causes of neonatal mortality.

 In a 3-months period, 114 Lacaune breed lambs died of which 52 animals were lost with clinical signs of infection. Heart and lung samples were collected and transmitted to the laboratory. Microbiological cultures following biochemical tests were conducted to identify bacterial infection of the lambs.

 A total of 52 out of 114 lambs (45.6%) were infected with bacteria. The bacteria including Escherichia coli (30.8%), Proteus mirabilis (19.2%), Pasteurella multocida (1.5%), Corynebacterium pseudotuberculosis (7.7%), Mannheimia haemolytica (3.9%), Staphylococcus epidermidis (1.9%) were isolated. The role of the identified pathogens was more significant in lamb death compared to non-infection causes. Diarrhea was the most infectious disease followed by septicemia and pneumonia. Escherichia coli was isolated significantly more than other bacterial agents (30.8%).

 The present findings showed Escherichia coli as the most common pathogen leading to lamb losses in the first two weeks of life. The hygienic practice which encompasses both environment and milking equipment, periodical flaming, and providing dry and clean bedding can dramatically decrease the infection among newborn animals. Reduction of the birth density and avoiding synchronization until the expert and labor capacity has reached the optimal level are necessary actions to reduce infectious diseases.