Increasing lamb survival in Prince Edward Island sheep flocks

The overall objective of this program of research was to describe patterns in lamb mortality in sheep flocks in Prince Edward Island (PEI), Canada, and to identify the most influential flock-level factors associated with lamb mortality risk. Data were collected retrospectively from 385 lamb post-mortem submissions (2005 to 2014), and prospectively over one year for 51 distinct lambing groups from 37 sheep flocks. The retrospective data revealed the importance of infectious causes of lamb mortality in PEI sheep flocks. The prospective data revealed that the mean group-level lamb mortality was 11.14% (± 6.64%), with 25 groups having lamb mortality greater than 10%, which is considered higher than acceptable. The following management factors most strongly contributed to decreased lamb mortality: using flock management goal-setting; seeking veterinary advice for medical treatment; using benzimidazole-derivative anthelminthics; feeding higher quality forage (higher crude protein, digestible energy, net energy for maintenance, and lower acid detergent fiber), applying visual lamb identification, feeding a coccidiostat to lambs, administering clostridial vaccination to lambs, and avoiding separation of hypothermic lambs from their dams. A history of neurological problems in ewes contributed to increased mortality in lambs. Gastrointestinal parasite infections, and selenium and vitamin E deficiencies, were widespread in the study flocks. These research findings suggest that, to improve lamb survival in PEI flocks, producers should work with their veterinarians to set flock performance goals, enhance the nutritional management of late-gestation ewes, and improve the preventative health management of ewes and lambs, especially related to gastrointestinal parasitism and infectious diseases.