Supplementation of progesterone via controlled internal drug release inserts during ovulation synchronization protocols in lactating dairy cows

Abstract

Our objective was to determine the effect of exogenous progesterone (P4) during a timed artificial insemination (TAI) protocol on pregnancies per AI (P/AI) in dairy cows not previously detected in estrus. Lactating cows (n=3,248) from 7 commercial dairy herds were submitted to a presynchronization protocol (2 injections of PGF(2alpha) 14 d apart; Presynch), and cows in estrus after the second PGF(2alpha) received AI (EDAI; n=1,583). Cows not inseminated by 12 to 14 d after the second PGF(2alpha) injection were submitted to a TAI protocol (GnRH on d 0, PGF(2alpha) on d 7, and GnRH+TAI 72h after PGF(2alpha)). At onset of the TAI protocol, cows were balanced by parity and days in milk and assigned randomly to receive no exogenous P4 (control, n=803) or a controlled internal drug release (CIDR) insert containing 1.38g of P4 from d 0 to 7 (CIDR, n=862). Blood samples were collected at the second PGF(2alpha) injection of the Presynch and on the day of the first GnRH injection of the TAI protocol for P4 determination. When P4 in both samples was <1 ng/mL, cows were classified as anovular, whereas cows having at least 1 sample >or=1 ng/mL were classified as cyclic. Concentration of P4 at 11 to 14 d after AI was determined in a subgroup of cows (n=453) from 2 herds. Pregnancy was diagnosed at 40+/-5 and 65+/-5 d after AI. Proportion of cows inseminated on estrus after the second PGF(2alpha) injection of the Presynch protocol differed among herds (range=26.7 to 59.8%). Overall P/AI for EDAI cows at 40+/-5 and 65+/-5 d were 36.2 and 33.7%, respectively, and pregnancy loss was 8.8%. Proportion of cyclic cows at the onset of the TAI protocol differed among herds (range from 66.5 to 86.3%), but did not differ between treatments (control=72.4%, CIDR=74.1%). Treatment affected P/AI at 40+/-5 (control=33.3%, CIDR=38.1%) and 65+/-5 (control=30.0%, CIDR=35.1%) d after AI but did not affect pregnancy loss (8.6%). Cyclic cows had greater P/AI at 40+/-5 (38.2 vs. 29.3%) and 65+/-5 d (35.1 vs. 26.1%) after AI, but cyclic status had no effect on pregnancy loss. Treatment affected P4 concentration after AI, with more CIDR cows having P4 >or=1 ng/mL (94.4 vs. 86.9%) and P4 >or=3.2 ng/mL (81.8 vs. 68.0%) at 11 to 14 d after AI compared with control cows. Treatment of cows not previously detected in estrus with a CIDR insert during a TAI protocol increased proportion of cows with functional CL after AI and P/AI.

Efficiency of Previously used CIDR Stored for a Prolonged Period

“…The improvement in the pregnancy-30 and 70 rates (around 10% and 5%; respectively) after incorporating a new CIDR into the Ovsnch protocol (New-CIDRsynch) is in agreement with previous studies incorporated the CIDR into the Ovsynch (Stevenson et al, 2006;Stevenson et al, 2008;Colazo et al, 2013) Presynch (Melendez et al, 2006;Chebel at al., 2010) or Cosynch (Stevenson et al, 2003) but in disagreement with other reports incorporated the CIDR into Presynch (Bartolome et al, 2009;Colazo et al, 2013) or Ovsynch (Rivera et al, 2005;Mendonçaa et al, 2012). The improvement occurred after incorporating the CIDR in to Ovsynch was explained by higher ability to induce estrous in non-cyclic cows (Stevenson et al, 2003;Cerri et al, 2009) or improving the fertility of cows which did not have a CL at the beginning of the protocol (Stevenson et al, 2008) or cows showed an early luteolysis before administration of PGF2α (Stevenson et al, 2006).…”

“…These results are in agreement with previous results in cows with unknown cyclicity status (Galvão et al, 2004;Stevenson et al, 2006), cows with no CL at the beginning of the protocol (Stevenson et al, 2006;Stevenson et al, 2008), cyclic or anovulatory cows (Galvão et al, 2004). Otherwise they are in disagreement with other reports on cows with different cyclicity status (Bartolome et al, 2009), cows with no CL or anovulatroy cows (Stevenson et al, 2006;Chebel et al, 2010). The cyclicity status of the cow greatly affected the embryonic loss after the GnRH-based synchronization protocol and the embryonic loss in noncycling cows was twice that in cycling cows (Galvão et al, 2004;Stevenson et al, 2006).…”

“…Based on conception rate, some studies reported no improvement either in heifers or cows (Galvão et al, 2004;Rivera et al, 2005;Mendonçaa et al, 2012). Other studies reported higher conception rate in cows that not previously observed in heat or without CL at the beginning of the protocol (Melendez et al, 2006;Stevenson et al, 2008;Chebel et al, 2010). Others showed controversial results (El-Zarkouny et al, 2004;Stevenson et al, 2006).…”

“…Several studies had investigated the effect of inserting a controlled internal drug-release (CIDR) or a progesterone-releasing intravaginal device (PRID) between the day 0 and 7of the Ovsynch (Stevenson et al, 2003;Galvão et al, 2004;El-Zarkouny et al, 2004;Rivera et al, 2005;Melendez et al, 2006;Stevenson et al, 2006;Stevenson et al, 2008;Chebel et al, 2010;Mendonçaa et al, 2012;Colazo et al, 2013). Based on conception rate, some studies reported no improvement either in heifers or cows (Galvão et al, 2004;Rivera et al, 2005;Mendonçaa et al, 2012).…”

Physiological and practical effects of progesterone on reproduction in dairy cattle

“…Similarly, concentrations of P4 on the day of PGF2α-induced luteolysis had a positive linear correlation with subsequent fertility (Diskin et al, 2006). More recent manipulative studies have shown some improvements (~5% to 7% increase in percentage pregnant) by using a controlled internal drug release (CIDR; releases P4) during the Ovsynch program before AI (Stevenson et al, 2006 andChebel et al, 2010;Bilby et al, 2013). Nevertheless, the results from these studies may not be due exclusively to the elevation in P4 produced by the CIDR, because improvements in synchronization may also accompany the use of a CIDR in the Ovsynch protocol.…”