season was not significant (P = 1.000), and the fit of the logistic regression model of
pregnancy failure after the first AI season was adequate (Hosmer-Lemeshow P = 0.129).
Heifers with RTS 1 and 2 combined had a lower calving rate and calved later
during the first calving season than those with RTS 4 and 5 combined (Table 4). In the
second calving season, the remaining heifers with initial RTS 1 and 2 combined tended to
have a lower calving rate than those with RTS 4 and 5 combined (P = 0.068), and they
calved later than those with RTS 3 (Table 4). From the third calving season onwards, no
differences in calving rates and days to calving between RTS categories in animals that
remained in the herd were evident (Table 4).