Wool loss in sheep

Sammanfattning: The idea behind this project came from a feed study executed two years during the lambing season. Both years wool loss was experienced. Low temperature in combination with shearing was believed to cause the wool loss the first year, while protein deficiency was believed to be the cause the second year. In the literature many causes of wool loss are described; mechanical wear, telogen effluvium, bacterial dermatitis, external parasites, wool break, scrapie, genetic causes and nutritional deficiencies are some examples. The aim of this thesis was to study causes for wool loss and how common wool loss is in Swedish sheep herds. A questionnaire was sent to 294 sheep owners in Sweden and complemented with an electronic questionnaire online, open for interested sheep owners. Five sheep owners answered further questions and five veterinarians have replied to questions about frequency of contacts regarding wool loss. The paper questionnaire (PQ) received 114 answers while the electronic questionnaire (EQ) received 56 answers. Of these, 42% of the PQ group had experienced wool loss while the corresponding number in the EQ group was 89%. The EQ group had larger herds, more crossbreeds and lambing during the winter months was more common. These farms experienced more wool loss during pregnancies and the wool loss was more commonly following a cold period. The primary causes for wool loss in the herds in this study are believed to be nutritional deficiencies and telogen effluvium. Telogen effluvium can develop after longer periods with high cortisol levels, which could be caused by cold stress due to shearing at low temperatures. To avoid wool loss it is important to have a well balanced feeding regime and to avoid causes for stress. Further research on other causes that potentially could cause telogen effluvium is advocated.