Variation in skin inflammatory responses between sheep bred for resistance or susceptibility to fleece rot and blowfly strike.

Sheep which have been bred for resistance (R) or susceptibility (S) to fleece rot and blowfly strike, were tested for intradermal inflammatory responses to excretory and secretory products of Lucilia cuprina larvae. R rams and lambs gave significantly larger skin weals than S animals. In addition, R and S rams were infected with L cuprina first instar larvae and wound exudates were collected. In the first 12 hours of infection R rams released significantly more exudate protein at the wound site than S rams. Correlations suggested that exudate production was stimulated by both larval burden and inflammatory responses, however, in the R group the inflammatory correlation was positive while in the S group it was negative. The results imply that inflammatory responses may play a role in innate resistance to L cuprina. The difference in inflammatory responses suggests genetic differences between the flocks and therefore could show some potential as a trait for indirect selection for resistance to fleece rot and body strike.