“THE HUMAN FACTOR” AS A CAUSE OF FAILURES DURING THE TREATMENT OF COWS USING THE OVS PROGRAM AND PROGESTERONE DEVICES

Abstract

In field conditions, vaginal gestagens or the OVS program are used to treat cows with
postpartum anestrus, non-pregnant or repeat breeder. The effectiveness of these varies
significantly. We assume that some of the failures can be attributed to organizational errors,
mostly consisting in insufficient observation of oestrus and incorrect timing of insemination.
The aim of the research was to determine: 1) the percentage of cows inseminated at the
correct term, 2) the percentage of cows inseminated at a date significantly different from the
expected date. In total, 1.026 cows from 12 different herds were used in the study. The
animals were classified into two groups. In group I, 458 females received intravaginal
progesterone device CIDR (Zoetis – containing 1.38 g P4) for 7 days, while 295 females
received the PRID progesterone device (CEVA containing 1.55 g P4). On the day of device
removal, a 500 μg i.m. injection of cloprostenol was administered. Cows were inseminated
according to heat symptoms. In group II – 273 cows were subjected to the OVS program (i.m.
injection of GnRH (Receptal, Intervet), prostaglandin (i.m. injection of 500 μg of cloprostenol
(Estrumate, MSD) on day 7 and the same dose like before GnRH on day 9). Females were
inseminated 24h after the final GnRH dose. Of the 753 PRID/CIDR cows, 568 (75.4%) showed
heat within the expected period, i.e. between 1 and 5 days after removal of the progesterone
IUD. Another 43 (5.7%) lost their insert. This group included additional 5 (0.6%) cows which
were inseminated on the 6th or 7th day after insertion of the insert. There were 48 cows in
total that lost the insert (6.3%; CIDR 7.4% vs. PRID – 4.7%). 137 (18.2%) cows were
inseminated more than 5 days after prostaglandin administration. In group II, 117 cows
(42.8%) were inseminated within an acceptable time, i.e. up to 3 days after GnRH
administration. The remaining females showed estrus > 5 days after P4 or before PG
administration – 156 (57.1%). Summing up; after the use of progesterone inserts, ¾ of the
cows were inseminated on time. In 1/5 cows, for various, unknown reasons (missing heat,
lack of heat, cows were inseminated at a later date. Using the OVS program, about 40% of
cows were inseminated on the indicated date. The remaining ones were inseminated too late
or much earlier, during the oestrus and ovulation synchronization program. It cannot be ruled
out that the moderate effectiveness of hormonal programs is a gross effect of organizational
errors and untimely insemination of cows.