Of 164 animal cases, 34 (20.7%) were rejected from the
program since no CL were detected on the day of cloprostenol/
dexcloprostenol administration. During summer
and winter seasons, 20.2% and 21.4% were rejected,
respectively. The rejection rates in parity * interval
between calving and entering the program (later "time
interval") groups are presented in Table 1. Differences in
rejections in cows between parity (p = 0.132), suckling (p
= 0.160) and time interval groups (p = 0.214) and seasons
(p = 0.932) were not statistically significant. The rejections
in heifers were not significantly different (p = 0.416) from
those in cows. However, heifers and old cows were
rejected numerically 10 to 20 percentage points more
than younger, parity 1-5, cows