Treatments for the synchronisation of bovine recipients for fixed-time embryo transfer and improvement of pregnancy rates

2012 ◽  
Vol 24 (1) ◽  
pp. 272 ◽  
Author(s):  
Gabriel A. Bó ◽  
Lucas Coelho Peres ◽  
Lucas E. Cutaia ◽  
Danilo Pincinato ◽  
Pietro S. Baruselli ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Transfer Program ◽  
Widespread Application ◽  
Wave Dynamics ◽  
Follicular Wave ◽  
Embryo Transfer Program ◽  
Conception Rates ◽  
On Farm

Although embryo transfer technology has been used commercially in cattle for many years, the inefficiency of oestrus detection, especially in recipients, has limited the widespread application of this technology. The most useful alternative to increase the number of recipients utilised in an embryo transfer program is the use of protocols that allow for embryo transfer without the need for oestrus detection, usually called fixed-time embryo transfer (FTET). Most current FTET protocols are based on progestin-releasing devices combined with oestradiol or GnRH, which control and synchronise follicular wave dynamics and ovulation. Conception rates to a single FTET have been reported to be similar to those after detection of oestrus, but pregnancy rates are higher because these treatments have increased the proportion of recipients that receive an embryo. Recent changes to treatments for FTET, such as the administration of eCG, have resulted in increased pregnancy rates and provide opportunities to make these treatments easier to perform on farm.

151 EFFECT OF RECIPIENT CATEGORY ON PREGNANCY RATES ON A BOVINE EMBRYO TRANSFER PROGRAM IN PATAGONIA, ARGENTINA

2008 ◽  
Vol 20 (1) ◽  
pp. 155
Author(s):  
J. Villarreal ◽  
A. Garcia Guerra ◽  
G. M. Brogliatti
Keyword(s):  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Point Of View ◽  
Bovine Embryo ◽  
Transfer Program ◽  
Chi Square ◽  
Lactating Cows ◽  
Significant Difference ◽  
Embryo Transfer Program ◽  
Condition Score

The fertility of the recipient is one of the more important factors conditioning the success of an embryo transfer (ET) program. Selection and management of recipients is a very important contributing factor to achieve high pregnancy rates (Stroud and Hasler 2006 Theriogenology 65, 65–76). From a reproductive point of view, a good recipient is a cow capable of receiving an embryo and taking it to term (Palma et al. 2001 Biotecnologia de la reproduccion, INTA). In beef and dairy cattle, recipients are categorized according to number of births, age, and condition score (Stroud and Hasler 2006). A retrospective analysis was done to confirm a relationship between recipient category, based on their physiologic and reproductive stage, and pregnancy rates. The analysis was done during January and February (2006–2007) based on data recovered from an embryo transfer program done in Chubut province (Patagonia) for the project ‘Polo Genetico Angus’ (Angus Association – Chubut government agreement). Two hundred and seven morulas and/or blastocysts, quality 1 or 2 frozen in 1.5 m ethylene glycol (IETS manual), were transferred randomly in 10 different farms. Embryos were thawed for 10 s at room temperature and 30 s in a water bath at 35°C and transferred by one single technician. Angus, Hereford, or its breeds were used as recipients. A reproductive exam was performed before embryo transfer and, based on it, recipients were classified into 4 categories: heifer (3–4 years old), lactating cow, weaned cow, and dry old cow (Table 1). The synchronization protocol used for recipients consisted of a single administration of D-cloprostenol and heat detection twice a day for 5 days. Data were analyzed by Cochran-Mantel-Haenszel test (chi-square). Results are shown in Table 1. There is a significant difference (P ≤ 0.05) in pregnancy rates among categories. Recipients with higher pregnancy rates were lactating cows and weaned cows 61.6% and 56.9%, respectively, compared to heifers, 45.3%; a lower pregnancy rate was founded in the dry old cows group. Dry cows were animals that failed to get pregnant during the last season. Heifers also were animals that failed the artificial insemination program. In both groups, the reduced fertility may explain their lower pregnancy rates. In conclusion, selection toward fertility of recipients is a very important factor to take into account to design a successful embryo transfer program. Table 1. Pregnancy rates for recipient categories in an ET program in Chubut (Patagonia), Argentina This research was supported by Centro Genetico Bovino Eolia.

scholarly journals Effect of the Flunixin Meglumine on Pregnancy Rates in an Equine Embryo Transfer Program

2018 ◽  
Vol 62 ◽  
pp. 40-43 ◽  
Author(s):  
Carolina Tiemi Cardoso Okada ◽  
Lorenzo Garrido Segabinazzi ◽  
André Maciel Crespilho ◽  
José Antônio Dell'Aqua ◽  
Marco Antonio Alvarenga
Keyword(s):  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Transfer Program ◽  
Flunixin Meglumine ◽  
Embryo Transfer Program

scholarly journals 181COMPARISON OF THE PREGNANCY RATES AFTER SYNCHRONIZATION OF OVULATION USING GnRH AND PGF2± IN RECIPIENT DAIRY CATTLE

2004 ◽  
Vol 16 (2) ◽  
pp. 212 ◽  
Author(s):  
T. Nishisouzu ◽  
M. Sugawara ◽  
S. Aoki ◽  
K. Kishida ◽  
M. Moriyoshi ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Control Group ◽  
Corpora Lutea ◽  
Transfer Program ◽  
Chi Square ◽  
Follicle Diameter

Treatments with GnRH and PGF2α for synchronization of ovulation has resulted in acceptable pregnancy rates after fixed-time artificial insemination in dairy cows without estrus detection. The objective of the present study was to evaluate the practicability of ovulation synchronization (Ovsynch, Pursley JR et al. 1995 Theriogenology 44, 915–923) in dairy cattle using GnRH and PGF2α for the embryo transfer recipients. Dairy cattle (cows; n=100, heifers; n=88) were randomly allocated to one of two groups. The control group (cows; n=45, heifers; n=37) was composed of cows in natural estrus. The ovulation synchronization group (cows; n=55, heifers; n=51) was treated with an intramuscular injection of 100μg of GnRH at a random stage of the estrous cycle. Seven days later, the cattle received PGF2α (Cows; 25–30mg) or PGF2α analog (Heifers; 0.5mg) in order to regress the corpora lutea (CL). Forty-eight hours later, cows and heifers received a second injection of 100μg GnRH. Embryo transfer was carried out 7 days after the second injection of GnRH in the ovsynch group and 7 days after estrus in the control group. The cattle judged to have CL 17mm were classified as acceptable recipients. The size of the follicles and the CL were determined to be of estrus stage and embryo transfer by means of ultrasonography. The mean numbers of follicles and CL were analyzed by ANOVA, while pregnancy rates were analyzed by chi-square test. The results are presented in the Table. The proportion of cows and heifers determined to be acceptable embryo transfers was not different between the control group and the ovsynch group. There were no differences in the proportion of acceptable embryo transfers between the control group and the ovsynch group. Follicle diameter at the time of estrus in the control group (cows; 20.7±0.7mm, heifers; 16.8±0.5mm) were significantly larger than that of the ovsynch group (cows; 18.0±1.0mm, heifers; 14.7±0.2mm) (P<0.05). Although CL diameter at the time of embryo transfer in heifers showed no differences between the control group and the ovsynch group (25.0±1.0mm v. 22.8±1.5mm), The CL diameter of the control cow group was larger than that of the ovsynch group (29.8±0.7mm v. 26.1±1.0mm, P<0.05). However, no differences in pregnancy rate were seen between the control group and the ovsynch group. These results suggest that ovsynch can be effectively applied in an embryo transfer program for cattle. Table 1 Proportion of acceptable embryo transfer recipients and pregnancy rate in dairy cattle in the control ovsynch groups

scholarly journals Gestational losses after innovating with two embryos in a fixed-time embryo transfer program

2021 ◽  
Vol 14 (10) ◽  
Author(s):  
Carla Neves Barbosa ◽  
Felipe De Col ◽  
Juan Carlos Domínguez Fernández de Tejerina ◽  
Rodolfo Cassimiro de Araujo Berber
Keyword(s):  
Embryo Transfer ◽  
Birth Rate ◽  
Considerable Increase ◽  
Hormonal Treatment ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Corpora Lutea ◽  
Transfer Program ◽  
Embryo Transfer Program ◽  
Group 1

The aim of this study was to quantify the pregnancy rate after implantation of two embryos after FTET protocols, as well as to monitor pregnancy losses until parturition, evaluating, mainly, if this strategy results in more number of animals born. Therefore, 423 multiparous recipients were selected, standardized in terms of body score, who had high-quality corpora lutea. Animals were randomly divided into two groups according to one or two embryos transferred (1 embryo = Control, n = 237; 2 embryos = Group 1, n = 186). All recipients received the same hormonal treatment, which consisted of administering, on Day 0, 2 mL of estradiol benzoate (Gonadiol, ZOETIS) + 1.9 g multidose 1st use progesterone implant (CIDR, ZOETIS); on Day 8 the implants were removed + injected 0.4 mL of estradiol cypionate (E.C.P, ZOETIS) + 1.5 mL of eCG (Novormon, ZOETIS) + 1 mL of dinoprost tromethamine (Lutalyse, ZOETIS). The animals were evaluated by ultrasonography at 30 and 60 days after embryo transfer, to diagnose the success rate and embryo losses during this period. Furthermore, information was collected on births, length of gestation, number of twin births, number of childbirth assistance and the weight of the calves. The results showed that Group 1 had better success than the Control, with higher conception rates at 30 days (68.3% vs. 53.2%, P<0.001) and at 60 days (62.9% vs. 52.3%; P<0 .05). The number of animals born was also higher for Group 1 (53.3% vs. 43.3%, P<0.01). The percentage of twins born in Group 1 was 17.9%, and the animals had lower weight compared to the Control (34.29 + 7.36 vs 37.63 + 5.73, P<0.05). The length of pregnancy and the number of assistances were similar between groups. In conclusion, the strategy adopted in this experiment suggests a considerable increase in the calf birth rate, but losses during pregnancy and their mechanisms need to be elucidated.

The evolution of improved and simplified superovulation protocols in cattle

2012 ◽  
Vol 24 (1) ◽  
pp. 278 ◽  
Author(s):  
Reuben J. Mapletoft ◽  
Gabriel A. Bó
Keyword(s):  
Embryo Transfer ◽  
Treatment Protocol ◽  
Bovine Embryo ◽  
Treatment Protocols ◽  
Wave Dynamics ◽  
Follicular Wave ◽  
Recent Treatment ◽  
Gonadotrophin Releasing Hormone ◽  
Animal Handling ◽  
On Farm

Superovulation protocols have improved greatly since the early days of bovine embryo transfer when purified gonadotrophins were not available, follicular wave dynamics were unknown physiological phenomena and prostaglandins were not available. Although superstimulatory protocols in cattle are normally initiated mid-cycle, elective control of follicular wave emergence and ovulation have had a great impact on the application of on-farm embryo transfer. However, the most common treatment for the synchronisation of follicular wave emergence involves the use of oestradiol, which cannot be used in many parts of the world. Therefore, the need for alternative treatments has driven recent research. An approach that has shown promise is to initiate follicle-stimulating hormone (FSH) treatments at the time of the emergence of the new follicular wave following ovulation induced by gonadotrophin-releasing hormone. Alternatively, it has been shown that it may be possible to ignore follicular wave status and, by extending the treatment protocol, induce subordinate follicles to superovulate. Finally, the short half-life of pituitary FSH necessitates twice-daily treatments, which are time-consuming, stressful and subject to error. Recent treatment protocols have permitted superstimulation with a single FSH treatment or two treatments 48 h apart, reducing the need for animal handling during gonadotrophin treatments.

scholarly journals 165 SYNCHRONIZATION TREATMENT WITH NEW AND REUSED CIDR-B DEVICES: ESTRUS AND PREGNANCY RATES IN AN EMBRYO TRANSFER PROGRAM

2005 ◽  
Vol 17 (2) ◽  
pp. 233
Author(s):  
C.W. Solorzano ◽  
J.H. Mendoza ◽  
A. Villa-Godoy ◽  
C.S. Galina ◽  
S. Romo
Keyword(s):  
Embryo Transfer ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Transfer Program ◽  
Embryo Transfer Program ◽  
Group 3 ◽  
Group 2 ◽  
Rectal Palpation ◽  
Group 1

An earlier study demonstrated that in CIDRs used in adult cows on two previous occasions, there was still a sufficient amount of progesterone (P4) remaining that allowed estrus synchronization in heifers (Solorzano et al. 2004 Reprod. Fert. Dev. 16, 214). However, the diverse conditions existing in that study made a statistical comparison impossible. The objective of this study was to study the effect of new and used CIDRs, combined with estradiol benzoate (EB) and prostaglandin F2-α (PGF) treatments, on estrus synchronization rates (ESR) and pregnancy rates (PR) in an embryo transfer program in Brangus cows in a tropical climate. We used the same set of CIDRs in the same location in cows of the same breed, age, and body condition during three consecutive weeks. Cows were randomly allocated to one of three treatment groups. In Group 1, all cows (n = 44) were treated with a new 1.9-g CIDR (CIDR-B, InterAg, Hamilton, New Zealand), combined with 2 mg EB on Day 0. In Group 2, all cows (n = 43) were treated with a reused (first reuse) 1.9-g CIDR and 2 mg EB on Day 0. In Group 3, all cows (n = 42) received a reused (second reuse) 1.9-g CIDR and 2 mg EB on Day 0. CIDR devices were removed on Day 7 and all cows received PGF (0.25 μg cloprostenol) at that time. Estrus was expected to occur 24 h later. Seven days after estrus all cows showing heat were examined by rectal palpation, and those with a CL 15 mm in diameter or larger were selected to receive a frozen/thawed embryo (in 1.5 M ethylene glycol) by nonsurgical direct transfer. PR were determined by rectal palpation 60 days after estrus. In Group 1, a total of 90.9% of the cows displayed signs of estrus (40/44), and 42% of those that received a frozen embryo were pregnant (16/38). In Group 2, a total of 88.4% of the treated cows showed signs of estrus (38/43), and 37% of those recipients became pregnant (13/35). In Group 3, 88% of treated cows showed signs of estrus (37/42), and 36% of cows receiving an embryo were pregnant (13/36). ESR and PR were compared by χ2 and Fisher's tests, and no differences were found among the three groups studied. This confirms that, in 1.9-g CIDRs used on two previous and consecutive occasions, there is still a sufficient amount of P4 remaining that allows successful estrus synchronization and pregnancy rates in a third use.

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