Effects of presynchronization and postinsemination treatments on pregnancy rates to a timed breeding Ovsynch protocol in dairy cows and heifers

2010 ◽  
Vol 90 (1) ◽  
pp. 35-44 ◽  
Author(s):  
M B Gordon ◽  
N Dinn ◽  
R Rajamahendran
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Dairy Cow ◽  
Artificial Insemination ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Timed Artificial Insemination ◽  
To Receive

This study examined two strategies to improve pregnancy rate (PR) following Ovsynch timed artificial insemination (TAI) for lactating dairy cows (n = 225) and nulliparous heifers (n = 87). Animals were assigned randomly to receive one of three treatments: Ovsynch protocol (GnRH 7 d before and 48 h after one PGF2α treatment), Presynch + Ovsynch (two treatments of PGF2α 14 d apart followed by Ovsynch 14 d later), or Ovsynch + Post-AI GnRH (GnRH 6 d after Ovsynch TAI) for first service breeding. Pregnancy rates among treatments were not different in lactating cows (42.5, 48.0, and 44.9%) or heifers (65.5, 58.6, and 58.6%) for Ovsynch, Presynch + Ovsynch, and Ovsynch + Post-AI, respectively. Cows treated with Ovsynch had lower PR when bred < 76 d in milk (DIM) compared with Presynch + Ovsynch or Ovsynch + Post-AI treatments. In addition, cows and heifers that received Post-AI GnRH had greater progesterone (P4) concentrations on day 21 and day 28 post-TAI than the Ovsynch group. Animals with higher P4 concentrations at initiation of Ovsynch had better PR than those with low P4 concentrations. Presynch animals had a greater proportion of animals with P4 values above 1 ng mL-1 at the initiation of Ovsynch than those animals in the Ovsynch group (74.5 vs. 59.4%). Heifers had lower PR if they were <14.6 mo of age (48.9 vs. 75%) or weighed <380 kg (47.4 vs. 70.8%). Although no significance differences in PR were observed between treatments in cows or heifers, DIM in cows and age and weight in heifers affected PR.Key words: Ovsynch, presynchronization, gonadotropin-releasing hormone, dairy heifer, dairy cow, timed artificial insemination

22 PREGNANCY RATES IN DAIRY COWS TREATED WITH PROGESTERONE-RELEASING DEVICES AND DIFFERENT GONADOTROPIN-RELEASING HORMONE OR ESTRADIOL PLUS EQUINE CHORIONIC GONADOTROPIN FIXED-TIME ARTIFICIAL INSEMINATION PROTOCOLS

2008 ◽  
Vol 20 (1) ◽  
pp. 91 ◽  
Author(s):  
G. Veneranda ◽  
L. Filippi ◽  
D. Racca ◽  
L. Cutaia ◽  
G. A. Bo
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Milk Yield ◽  
Artificial Insemination ◽  
Fixed Time ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Device Removal ◽  
Treatment Groups ◽  
Lactating Dairy Cows

We have previously shown that the addition of eCG improved pregnancy rates following fixed-time artificial insemination (FTAI) in lactating dairy cows treated with estradiol benzoate (EB) and progesterone releasing devices (Veneranda et al. 2006 Reprod. Fertil. Dev. 18, 118). An experiment was designed to compare pregnancy rates in lactating dairy cows treated with progesterone-releasing devices and EB plus eCG with different gonadotropin-releasing hormone (GnRH)-based protocols. Five-hundred lactating dairy cows between 30 and 51 days postpartum (when prostaglandin F (PGF) treatments were given in the Pre-Synch groups), with a milk yield of 29.5 � 7.0 kg per day (range 13.0 to 46.0 kg) and a body condition score (BCS) between 2.5 to 3.5 out of 5 were used. Cows were blocked by days postpartum and randomly assigned to five treatment groups. Cows in the Pre-Synch group received PGF 28 and 14 days prior to the insertion of a DIB device (1 g progesterone, Syntex SA, Buenos Aires, Argentina) and the administration of 50 µg of Lecirelin (GnRH, Ovusin, Syntex SA) IM (Day 0). On Day 7, DIB were removed and cows received PGF (0.5 mg cloprostenol, Ciclase, Syntex SA). On Day 9, cows received a second GnRH treatment and were FTAI 16 h later (60 h after device removal). Cows in the Modified Pre-Synch group were treated similarly except that they received a DIB for 7 days prior to the second PGF injection and no DIB at the time of the first GnRH. Cows in the P4-Synch group were treated as those in the Pre-synch group but did not receive the two doses of PGF 28 and 14 days earlier. Cows in the P4 + EB + eCG groups received a DIB for 8 days, 2 mg of EB at DIB insertion (Day 0), and PGF and 400 IU eCG (Novormon, Syntex SA) IM at DIB removal (Day 8); they were subdivided to receive 1 mg of EB on Day 9 (P4 + EB + eCG + EB group) or GnRH on Day 10 (P4 + EB + eCG + GnRH group). Cows in these latter two groups were also FTAI 60 h after device removal. Pregnancy was determined by rectal palpation 50 days after FTAI and data were analyzed by logistic regression. Pregnancy rates were not affected by BCS, days postpartum, or milk yield (P > 0.5). However, there was a significant group effect due to a higher (P < 0.05) pregnancy rate in the P4 + EB + eCG + EB (49%) and P4 + EB + eCG + GnRH (44%) treatment groups than in those in the Modified Pre-Synch group (30%). Pregnancy rate in the P4-Synch group (39%) was lower (P < 0.05) than those in the P4 + EB + eCG + EB group but not different from the others. Finally, pregnancy rate in Pre-Synch group (41%) was intermediate and not different from the other treatment groups. Results of these experiments suggest that treatments with progesterone-releasing devices, EB, and eCG result in pregnancy rates that are comparable to or better than those obtained in GnRH-based protocols in lactating dairy cows. Further studies are needed to investigate whether eCG could increase pregnancy rates in cows treated with GnRH and progesterone-releasing devices. The authors thank Syntex SA for providing the hormones used in the study.

18 PREGNANCY RATES IN LACTATING DAIRY COWS TREATED WITH GONADOTROPIN-RELEASING HORMONE-BASED SYNCHRONIZATION PROGRAMS AND INSEMINATED AT A FIXED TIME

2013 ◽  
Vol 25 (1) ◽  
pp. 156
Author(s):  
D. Romero ◽  
G. Romero ◽  
G. Veneranda ◽  
L. Filippi ◽  
D. Racca ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Milk Production ◽  
Animal Health ◽  
Fixed Time ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Lactating Dairy Cows ◽  
Pfizer Animal Health ◽  
Group 3

An experiment was designed to compare pregnancy rates in lactating dairy cows synchronized with a 7-day CIDR-Synch or a 5-day CIDR-Synch program and to determine if the addition of a second prostaglandin F2α (PGF) injection to the 7-day CIDR-Synch program would improve pregnancy rates following fixed-time AI (FTAI). The experiments were performed on 2 dairy farms in Argentina, with year-round calving and a mixed feeding system (35% grazing plus 65% corn silage and grain). Cows (n = 621) were 39.3 ± 6.5 days in milk (DIM, mean ± SD) when they were enrolled in the program, had 2.4 ± 1.5 lactations and a body condition score (BCS) of 3.1 ± 0.2 (range: 2.7 to 4.0). All cows received a pre-synchronization treatment with 2 doses of prostaglandin (PGF, 25 mg of dinoprost, Lutalyse, Pfizer Animal Health, Argentina) 14 days apart, and 11 days after the second PGF (Day 0) received 10 µg of Buserelin (GnRH, Receptal, MSD-Intervet, Argentina) and a CIDR device (1.9 g of progesterone, Pfizer Animal Health). Cows were randomly allocated to 1 of 3 groups. The CIDR devices were removed and PGF was administered to cows in Groups 1 and 2 on Day 7. A second GnRH was given 56 h later and cows experienced FTAI 16 h after gonadotropin-releasing hormone (GnRH) injection (i.e. 72 h after CIDR removal). Cows in Group 2 also received a second PGF injection on the afternoon of Day 7. Cows in Group 3 had the CIDR removed and received 2 PGF injections 12 h apart on Day 5. A second dose of GnRH was given and FTAI was performed at the same time, on Day 8 (i.e. 72 h after CIDR removal). All cows were examined by ultrasonography (Aloka 500V, Aloka, Tokyo, Japan) on the day of the first PGF injection and at CIDR removal to determine the presence and number of corpora lutea (CL), and 30 days after FTAI to determine pregnancy status. Data were analyzed by logistic regression to determine the effects of treatment, parity, days postpartum, milk production, BCS, presence of a CL at enrollment, and number of CL at the time of CIDR removal on pregnancy rates. Overall pregnancy rates did not differ among groups: 32.9% (68/207), 38.2% (78/204), and 38.3% (80/209) for Groups 1, 2, and 3, respectively (P = 0.2). Although the number of CL present at CIDR removal did not significantly affect pregnancy rates (P = 0.4), pregnancy rates in cows with 1 CL in Groups 1 and 2 tended to differ [29.0% (11/38) v. 48.9% (21/43); P < 0.07], but neither differed from that in Group 3 [37.2% (16/43)]. No differences were detected among groups in cows without a CL at CIDR removal [overall pregnancy rate: 29.4% (5/17)] and those with ≥2 CL [overall pregnancy rate: 36.1% (173/479)]. Among the other variables evaluated, first-parity cows had 1.96 (1.38–2.78) times more chance of getting pregnant than second-or-more-parity cows (P = 0.002) and cows with BCS >3 had 1.63 (1.16–2.28) times more chance of getting pregnant than those with BCS <3 (P = 0.003). Finally, herd, days postpartum, milk production, and presence of a CL at enrollment did not significantly affect pregnancy rates. We concluded that the 3 treatments resulted in similar pregnancy rates for lactating dairy cows and that the benefit of adding a second PGF injection to the 7-day protocol was only marginal in cows with 1 CL at CIDR removal.

7 COMPARISON OF TIMED ARTIFICIAL INSEMINATION PROTOCOLS USING PROSTAGLANDIN F2α+ESTRADIOL OR PROSTAGLANDIN F2α+ESTRADIOL+GONADOTROPIN-RELEASING HORMONE IN DAIRY COWS

2012 ◽  
Vol 24 (1) ◽  
pp. 115
Author(s):  
J. K. Jeong ◽  
H. G. Kang ◽  
I. H. Kim
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Chi Square ◽  
Array Transducer ◽  
Chi Square Test ◽  
Timed Artificial Insemination

This study compared pregnancy rates following 2 timed artificial insemination (TAI) protocols using PGF2α + oestradiol or PGF2α + oestradiol + GnRH in dairy cows. Four hundred fifty-five Holstein dairy cows, 2.2 ± 0.1 in parity, 148.3 ± 3.6 days in milk, with corpus luteum of greater than 20 mm diameter confirmed by ultrasonography (Tringa Linear with 5.0 MHz array transducer; Esaote Pie Medical, Maastricht, the Netherlands) were randomly divided into two treatments: an injection of 500 μg of cloprostenol, PGF2α analogue (Iliren cycle BP®, Intervet International GmbH, Unterschleissheim, Germany) and an injection of 2 mg of oestradiol benzoate (EB, SY Esrone, Samyang, Seoul, Korea) 36 h later (PGF2α + EB group, n = 257), or an injection of 500 μg of cloprostenol, an injection of 2 mg of EB 36 h later and an additional injection of 100 μg of gonadorelin, GnRH analogue (Godorel, Uni-Biotech Co., Ltd., Korea) 24 h later (PGF2α + EB + GnRH group, n = 198). All cows in the two groups received TAI 24 h after the EB injection. Pregnancy was determined at 40 to 50 days after TAI by using both ultrasonography and rectal palpation. Pregnancy rates between the PGF2α + EB and PGF2α + EB + GnRH groups were compared by the chi-square test using the SAS program (version 9.1: SAS Institute Inc., Cary, NC, USA). Pregnancy rate following TAI did not differ between the PGF2α + EB (32.7%) and PGF2α + EB + GnRH groups (34.9%; P > 0.05). In conclusion, addition of GnRH for TAI protocol using PGF2α + oestradiol did not improve pregnancy rate in dairy cows.

19 PREGNANCY RATES IN DAIRY COWS TREATED WITH INTRAVAGINAL PROGESTERONE DEVICES AND DIFFERENT FIXED-TIME AI PROTOCOLS

2006 ◽  
Vol 18 (2) ◽  
pp. 118 ◽  
Author(s):  
G. Veneranda ◽  
L. Filippi ◽  
D. Racca ◽  
G. Romero ◽  
E. Balla ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Milk Yield ◽  
Body Condition Score ◽  
Animal Health ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Treatment Groups ◽  
Lactating Dairy Cows ◽  
To Receive

Two experiments were designed to evaluate the effect of different treatments for the synchronization of ovulation on pregnancy rates following fixed-time AI (FTAI) of lactating dairy cows. In Experiment 1, 394 Holstein cows that were 61.7 � 13.6 days postpartum (range 35 to 94 days), with a milk yield of 30.7 � 6.8 liters per day (range 12.0 to 52.4 liters) and a body condition score (BCS) between 2.5 to 3.5 out of 5, were used. Cows were blocked by days postpartum and milk yield and randomly assigned to one of four treatment groups. Cows in P4+EB treatment groups received an intravaginal DIB device (1 g P4; Syntex, Argentina) and 2 mg of estradiol benzoate (EB; Syntex) i.m. on Day 0. On Day 8, DIB devices were removed, and cows received PGF (150 �g D+cloprostenol: Ciclase; Syntex), and were subdivided to receive 400 IU eCG (Novormon 5000, Syntex) i.m. or no further treatment at that time. On Day 9, all cows received 1 mg of EB and were FTAI 60 h after DIB removal. Cows in P4-Synch groups received a DIB device and 50 �g of GnRH (Lecirelina, Gonasyn; Syntex) i.m. on Day 0. On Day 7, DIB devices were removed; cows received PGF and were divided to receive 400 IU eCG i.m. or no further treatment. On Day 9, all cows received a second GnRH treatment and were FTAI 60 h after DIB removal. Blood samples were taken on Days -10 and 0 to determine plasma P4 concentrations; 93% of the cows had >1 ng/mL P4 in at least one sample. In Experiment 2, 200 lactating cows from the same farm were treated with the P4+EB+eCG and P4-Synch without eCG treatments with either a DIB or a CIDR-B (1.9 g P4; Pfizer Animal Health, Groton, CT, USA) in a 2 � 2 factorial design. Cows were examined by rectal palpation 50 days after FTAI to determine pregnancy status, and data were analyzed by chi-square Mantel-Haenszel test. There was an EB/GnRH by eCG interaction (P < 0.05) which was attributed to a higher pregnancy rate in the P4+EB+eCG group (44/98; 44.9%) than in the P4+EB without eCG group (30/100; 30.0%) and P4-Synch+eCG group (30/98; 30.6%); the P4-Synch without eCG group had an intermediate pregnancy rate that did not differ from the other treatment groups (37/98; 38.8%). In Experiment 2, no significant differences (P = 0.40) in pregnancy rates were detected between cows treated with DIB (51/100; 51.0%) or CIDR-B (42/100; 42.0%), and there was no difference (P = 0.18) between P4+EB+eCG (52/100; 52.0%) and P4-Synch without eCG (41/100; 41.0%) treated groups. Results suggest that the addition of eCG will improve pregnancy rates following FTAI in lactating dairy cows treated with EB but not in those treated with GnRH at the time of insertion and after removal of a P4 releasing device. Although treatment with P4+EB+eCG resulted in numerically higher pregnancy rates, results were not different from those obtained in the GnRH-based treatment, without the addition of eCG.

347 ARTIFICIAL INSEMINATION OF LACTATING HOLSTEIN COWS WITH SEXED SPERM

2006 ◽  
Vol 18 (2) ◽  
pp. 281 ◽  
Author(s):  
E. Crichton ◽  
S. Huffman ◽  
K. McSweeney ◽  
J. Schenk
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Fetal Death ◽  
Laser Intensity ◽  
Holstein Cows ◽  
Fetal Sex ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Holstein Bulls

The recommended use of sexed sperm has been limited to heifers. The objective of this field trial was to determine pregnancy rates in lactating dairy cows following artificial insemination of 2 or 10 � 106 sexed or 10 � 106 unsexed frozen/thawed sperm. Sperm were separated into X chromosome-bearing populations at rates of 3000-5000/s, on the basis of DNA content, with a flow cytometer/sperm sorter operating at 40 psi and using 150 mW of laser intensity. Sperm were sorted, collected and cryopreserved in a Tris-based medium. Holstein cows, averaging 2.4 lactations (range: 1-9), were presynchronized with prostaglandin F2� (PGF)2�; (25 mg) i.m. at 40-58 days in milk (DIM) (average, 44 days). A second dose of PGF2� (25 mg) i.m. was administered 14 days later. All cows were screened with ultrasound 14 days later, and those with normal ovarian and uterine status were used for this study. Qualifying cows received 100 �g gonadotropin-releasing hormone (GnRH) i.m. (average, 72 DIM) and 25 mg PGF2� i.m. 7 days later, and then 100 �g GnRH i.m. 2 days after the prostaglandin. Cows (n = 172) were fixed-timed inseminated 16-19 h after the last GnRH treatment, balanced over three sperm insemination treatments, two Holstein bulls, and two inseminators. Both 32-day pregnancy and 60-day fetal sex were determined using ultrasound. Cows carrying fetuses identified as dying at the 32-day ultrasound check were considered not pregnant. Data were subjected to ANOVA. Effects of sperm treatment, bulls, inseminators, and subsequent interactions on pregnancy rate were not significant (P > 0.05). The 32-day pregnancy rate and 95% confidence interval for 10 � 106 unsexed, 10 � 106 sexed, and 2 � 106 sexed inseminates were 55.6 (42.5-68.6), 43.9 (31.6-57.0), and 40.4% (28.4-53.6), respectively. Additionally, DIM or cow parity did not affect pregnancy rate (P > 0.05). Fetal death (<32 days) for unsexed inseminates was 5.5% (two pregnancies) compared to 9.5% (four pregnancies) for pooled sexed inseminates (P > 0.05). There were four confirmed pregnancies of sexed sperm that also aborted between Days 32-60. Fetal sex ratio was significantly altered (P < 0.05) for sexed (93% female fetuses) compared to unsexed (52% female fetuses) inseminates. Pregnancy rate in these selected lactating cows inseminated with sexed sperm was not significantly lower (P > 0.05) than that for unsexed sperm. However, these results should be viewed cautiously due to the limited numbers of cows used. Successful use of sexed sperm in dairy cows, which approached an elective waiting period of 80 DIM, was achieved with cows that were selected for reproductive status prior to insemination.

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