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

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.

2012 ◽  
Vol 24 (1) ◽  
pp. 115
Author(s):  
J. K. Jeong ◽  
H. G. Kang ◽  
I. H. Kim

This study determined the effect of supplementation with oestradiol or oestradiol plus GnRH after PGF2α administration on pregnancy rates after timed artificial insemination (TAI) in dairy cows. Three hundred and six Holstein dairy cows with corpus luteum confirmed by ultrasonography (Tringa Linear with 5.0 MHz array transducer; Esaote Pie Medical, Maastricht, the Netherlands) were randomly allocated to three treatments: a single injection of 500 μg of cloprostenol, PGF2α analogue (Estrumate, Schering-Plough Animal Health, Friesoythe, Germany; PGF2α group, n = 115) designated as 0 h, an injection of 500 μg of cloprostenol and an injection of 1 mg of oestradiol benzoate (EB, SY Esrone; Samyang, Seoul, Korea) 56 h later (PGF2α + EB group, n = 114), or the same treatment as in the PGF2α + EB group 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 = 77). All cows in each group received TAI 80 h after the PGF2α injection. Pregnancy was determined at 40 to 50 days after TAI by using both ultrasonography and rectal palpation. Pregnancy rate among 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 were higher (P < 0.05) in the PGF2α + EB + GnRH group (34/77, 44.2%) than in the PGF2α group (31/115, 27.0%), with the PGF2α + EB group intermediate (39/114, 34.2%). In conclusion, the supplementation with oestradiol plus GnRH after PGF2α administration improved pregnancy rate after TAI in dairy cows. This work was supported by the research grant of the Chungbuk National University in 2011.


2016 ◽  
Vol 51 (6) ◽  
pp. 738-744 ◽  
Author(s):  
Luiz Francisco Machado Pfeifer ◽  
Luiz Gustavo Bruno Siqueira ◽  
Eduardo Kenji Nunes Arashiro ◽  
Natália Ávila de Castro ◽  
João Henrique Moreira Viana

Abstract: The objective of this work was to compare two types of ovulation inducers - estradiol benzoate (EB group) or prostaglandin F2α (PG group) -, in postpartum dairy cows subjected to timed artificial insemination (TAI). Lactating Holstein-Gir crossbred cows (n=118) with 60 to 120 days of milk production were used in this study. All cows were treated with an intravaginal progesterone-releasing device (CIDR) plus 2 mg of estradiol benzoate (EB) on day 0. The CIDR inserts were removed on day 9, and all cows received 500 µg sodium cloprostenol. Twenty-four hours after CIDR removal, cows were randomly assigned into two treatment groups and were given either 1 mg of EB i.m. (EB group) or 500 µg sodium cloprostenol i.m. (PG group). TAI were performed at 52 to 54 hours, in both EB and PG groups, after CIDR removal. No differences were observed in the ovulation (85.2% vs 72.7%) and pregnancy rates (40.7% vs 38.2%) between the EB and PG groups, respectively. Fertility is similar in the TAI protocols that use prostaglandin F2α or EB to induce ovulation in lactating dairy cows.


2008 ◽  
Vol 88 (3) ◽  
pp. 457-461
Author(s):  
M. Aali ◽  
T. Pretheeban ◽  
G. Giritharan ◽  
R. Rajamahendran

Peripheral progesterone (P4) concentrations as well as pregnancy rates (PR) between cows treated with Ovsynch or CIDR ovulation synchronization/TAI protocols were compared. Two hundred and twenty-seven postpartum lactating Holstein cows were randomly assigned to Ovsynch (n = 111) or CIDR (n = 116) ovulation synchronization/TAI protocols. Pregnancy was diagnosed by ultrasonography at day 35 after TAI and later confirmed by rectal palpation at day 60 post TAI. Milk samples were taken from the beginning of treatment (day -10) until day 35 after TAI (day 0) for P4 determination. Pregnancy rates for Ovsynch and CIDR groups of cows were 31 and 41%, respectively. The PR of ovulation synchronized cows for Ovsynch and CIDR groups were 49 and 69%, respectively. Progesterone levels during the sampling period were similar (P > 0.05) between Ovsynch and CIDR treated cows. Key words: Pregnancy rate, progesterone, Ovsynch, CIDR, cows


2010 ◽  
Vol 90 (1) ◽  
pp. 35-44 ◽  
Author(s):  
M B Gordon ◽  
N Dinn ◽  
R Rajamahendran

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


2021 ◽  
Vol 92 (1) ◽  
Author(s):  
Peng Zheng ◽  
He Huang ◽  
Xiaoyu Li ◽  
Fushuo Huang ◽  
Samson Olugbenga Adeniran ◽  
...  

Author(s):  
Abubakr O. Ismail ◽  
◽  
Erneo B. Ochi ◽  
Ambrose S. Jubara ◽  
Bakri Ahmed A/Rahim ◽  
...  

A comparative hormonal study of prostaglandin, gonadotropin releasing hormone and their combination was conducted on 30 randomly selected cross-bred dairy cows of SEMEX project for artificial insemination in Hillat Kuku, Khartoum North, Sudan. The study attempts to determine the response of the animals to hormonal induction and synchronization of estrous as well as fertility following fixed time artificial insemination. Three treatment groups of 10 cows each were undertaken. Groups 1, 2 and 3 involved administration of prostaglandin F2α (PGF2α), gonadotropin releasing hormone (GnRH) and a combination of PGF2α + GnRH, respectively. Descriptive statistical analysis was performed. The results revealed that all the three protocols induced and synchronized estrous were almost synchronous in all the treated groups. However, protocol 3 revealed a significantly (p<0.05) better result of 70% pregnancy rate compared to other two protocols that equally provided 50% pregnancy rates. The study resolves that protocol 3 be highly recommended to change the mindset of farmers about the spread of reproductive technology in Sudan. Protocols 1 and 2 provided acceptable pregnancy rates that can be enhanced with the improvement of management.


2010 ◽  
Vol 39 (10) ◽  
pp. 2182-2186
Author(s):  
Cristiane Reinher ◽  
Júlio Otávio Jardim Barcellos ◽  
Vanessa Peripolli ◽  
Ênio Rosa Prates ◽  
Maria Eugênia Andrighetto Canozzi

It was evaluated in this work the effect of calving sub-season on the pregnancy rate of 7,726 multiparous Hereford beef cows grazing on natural pastures in southern Brazil, from 1994 to 2007. Calving sub-season periods were divided in 20-day intervals from August 12th to 31st; from September 1st to 20th; from September 21st to October 10th; from October 11th to 31st; from November 1st to 20th. Calving in each sub-season and pregnancy rate (PR) were analyzed by the Chi-square test. Overall means of each sub-season were 92.7% (from August 12th to 31st), 90.6% (from September 1st to 20th), 82.1% (from September 21st to October 10th), 77.7% (from October 11th to 31st), and 70.6% (from November 1st to 20th). Calving sub-season significantly influenced pregnancy rate. Cows which calved in the initial sub-season showed higher pregnancy rates than cows which calved from the fourth calving sub-season. However this difference did not occur in 1999 and in 2007 since calving rates did not statistically differ among the five sub-seasons. In 1998 and 2004, calving rates were lower and the effects of calving sub-season on pregnancy rates were higher, possibly due to climate variations. In general, pregnancy rate decreases as calving occurs later in the year, particularly in years when the weather adversely affects pasture growth.


2022 ◽  
Author(s):  
Murat Can Demir ◽  
Cihan Kaçar ◽  
Umut Çağın Arı ◽  
Semra Kaya ◽  
Oğuz Merhan ◽  
...  

Abstract The present study aimed to determine the effects of progesterone-based gonadotropin-releasing hormone (GnRH), prostaglandin F2α (PGF2α), and equine chorionic gonadotropin (eCG) injections on progesterone profiles and pregnancy rates in cows with no estrus symptoms within 60 days after parturition. A total of 80 cows were included in the study. All animals had the progesterone-releasing device PRID®Delta placed intravaginally for nine days with an injection of GnRH. On the eighth day, PGF2α was injected, and PRID®Delta was removed from the vagina on day nine. Artificial insemination was carried out 60 hours after PRID®Delta removal. In half of the animals (n = 40), 600 IU of eCG was injected when PRID®Delta was removed on the ninth day before artificial insemination 60 hours later. Blood samples were taken from the tail vein on days 0 and 8 to determine progesterone levels. The pregnancy rate in the group that received eCG was 37.5%, while it was 27.5% in those that did not (P = 0.4). While the dominant follicle diameter was 15.5 mm in cows injected with eCG during timed artificial insemination, the follicle diameter was 12.4 mm in cows with no eCG injection (P <0.001). There were no differences in serum progesterone values in blood samples taken until the time of artificial insemination. However, progesterone values in the blood taken during artificial insemination were 0.94 ng/ml in the eCG- group and 0.72 ng/ml in the eCG+ group (P <0.05). As a result, it was determined that eCG injections, in addition to progesterone-based GnRH and PGF2α applications, increased the pregnancy rates in cows without symptoms of estrus. The dominant follicle diameter was larger in cows treated with eCG during artificial insemination; however, follicle size did not increase the pregnancy rate.


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