Causes of enlarged sternal bursas (breast blisters)

Bursas were taken weekly as normal turkeys developed from 3 to 22 weeks of age, and no specific bacterial or viral infection was found. Bacterial cultures were also made of condemned bursas taken at processing. Of 144 collected, 91% were sterile; the others had staphylococci, streptococci, or coliform organisms. Experiments with turkeys measured the effect of strain, body conformation, completeness of breast-feather cover, protection of the keel with sheepskins, age when put on range, and type of range on the incidence of enlarged sternal bursas. The strain difference of 25.4% breast blisters against 11.5% was highly significant (99% confidence). In one experiment the effect of feather cover was significant at the 95% level of confidence (61.7% breast blisters with no feather cover, versus 40% with complete feather cover). The effect of protecting the breast with sheepskin was significant at the 95% level of confidence in reducing incidence of breast blisters. There was no significant difference in the incidence of breast blisters in relation to body conformation, age, or type of range.