All reproductive examinations were carried out by three
experienced operators that were trained on both scoring
systems using an standard operating procedure drawn up
for the study. Each cow received one prebreeding examination
(PBE), conducted as described by Mee [20,32], between
21 and 38 days postpartum (mean 28 days). On the
day of the PBE, all the animals were identified and body
condition scored using the five-point body condition score
(BCS) system as described by Edmondson et al. [33]. The
perineal area of each cow was cleaned with paper towel,
after which the vaginal mucus samples were taken by
means of a Metricheck device (a small cup-shape instrument
that collects potential mucus) as described by
McDougall et al [16]. Any mucus collected in the cup was
subsequently scored as MS on a scale of 0 to 3 (MS0: no or
clear mucus; MS1: mucus with specks of purulent material;
MS2: