Abstract :
Objective of the study was to evaluate effects of the procedure followed for udder dryingoff
(i.e., progressive or abrupt cessation of lactation) in subsequent mammary infection and
development of mastitis. In ewes of group A (n = 19), drying-off took place progressively
during a period of 22 days; in ewes of group B (n = 12), udder drying-off took place abruptly.
Samples of teat duct material and of milk for bacteriological and cytological examination
were collected before start of the drying-off procedure, as well as on two occasions after the
subsequent lambing: the first immediately after lambing - before the lambs sucked their
dam for the first time (15 ewes: 9 group A and 6 group B) or up to the 1st day after lambing
(16 ewes: 10 group A and 6 group B) and the second on the 4th or 5th day after lambing (all
ewes). Median time to first teat duct or mammary infection post-partum was 0 days (teat
ducts and mammary glands) for group A and 2.25 and 0 days (teat ducts and mammary
glands, respectively) for group B (P > 0.38). Of the 33 bacterial isolates obtained, 79% were
coagulase-negative staphylococci. No significant differences were observed between the
two groups in the post-partum frequency of teat duct infection (P > 0.13), of mammary infection
(P > 0.8), of subclinical mastitis (P > 0.78) or of abnormal findings in a mammary gland
(P > 0.11). No significant differences were seen between the two groups in the post-partum
incidence risk of any of the outcomes studied: teat duct infection (P = 0.545), mammary
infection (P = 0.647), subclinical mastitis (P = 0.476) or abnormal findings in a mammary
gland (P = 0.259). No significant differences were evident between the two groups in cure
rate of abnormal findings in a mammary gland (P = 0.847). The results support a hypothesis
that the procedure for udder drying-off (i.e., progressive or abrupt cessation of lactation)
does not affect the risk of subsequent mammary infection and development of mastitis
