scholarly journals Two hormonal protocols for timed artificial insemination in mares under different residence times of the progesterone intravaginal device

2021 ◽  
Vol 37 (2) ◽  
pp. 138–146-138–146
Author(s):  
B L Zielinski ◽  
C E Camargo ◽  
G P Amaral Filho ◽  
R D Ollhoff ◽  
D Portela Cardozo ◽  
...  
2014 ◽  
Vol 26 (1) ◽  
pp. 121
Author(s):  
D. G. Souza ◽  
A. Martins ◽  
E. Oba ◽  
A. S. Camargos ◽  
E. P. Moreira ◽  
...  

Reducing animal handling and costs in timed artificial insemination (TAI) systems are of great interest in animal production, regardless of the species. Thus, this study was carried out to investigate the effects of administering oestradiol cypionate (EC) or hCG to induce ovulation in buffalo (Bubalus bubalis) in TAI programs. The 79 Bufalipso heifers housed at Institute of Animal Science, San José de las Lajas, Cuba, were, on average, 24 months of age with a body weight of 310 to 380 kg at the beginning of the experiment. The investigation was conducted out of the breeding season (25 June through 28 July 2012). Heifers were randomly assigned to 1 of 3 treatment groups; either hCG (control group) or EC1 and EC2, in which TAI was performed at either 48 or 56 h after the EC injection, respectively. On the first day of the treatment regime (Day 0), animals received oestradiol benzoate (2 mg i.m.; Sincrodiol®, Ourofino, Brazil), followed by the insertion of an intravaginal device containing 1 g of progesterone (Primer®, Tecnopec, São Paolo, Brazil). On Day 9, an intramuscular luteolytic dose of cloprostenol (500 μg; Ciosin®, Intervet, Brazil) and eCG (500 UI; Novormon®, Intervet) were given in all heifers along with the removal of the intravaginal device. On the same day, 0.5 mg of EC (ECP®, Pfizer, Brazil) was administered intramuscularly in the EC1and EC2 groups. Animals in the hCG group received hCG (1000 IU i.m.; Vetecor®, Hertape Calier, Spain) on Day 11 and were inseminated 14 h later. Pregnancy diagnosis was performed by ultrasound 35 days after TAI. Data were analysed by a chi-squared test, with P < 0.05 taken as significant. There were no differences among treatment groups, with values of 57.7 (15/26), 60.7 (17/28), and 64% (16/25) for the EC1, EC2, and hCG groups, respectively. In conclusion, oestradiol cypionate was effective at inducing ovulation in buffalo heifers in TAI programs comparable to the control group, as evidenced by the conception rates. In addition, animals subjected to the EC protocol pass just 3 times through the corral instead of 4 when receiving hCG, which decreases the animal handling and costs.


2021 ◽  
Vol 73 (1) ◽  
pp. 41-48
Author(s):  
J.H.A. Weiller ◽  
M.V.C. Ferraz Júnior ◽  
F. Jacobs Dias ◽  
G.Y. Hattori

ABSTRACT This study aimed to determine the efficiency of estradiol cypionate (EC) as an ovulation inducer in a Timed Artificial Insemination protocol. 69 buffalo cows received an intravaginal progesterone device and 2mg of estradiol benzoate (EB) at D0. On D9, the intravaginal device was removed and 0.53mg of prostaglandin (PGF2α) and 400UI of equine chorionic gonadotrophin (eCG) were applied. The cows were distributed into two groups: the first group received 1mg of EC (ECG) in D9, and the second group received 1mg of EB (EBG) in D10. Inseminations occurred on D11. Ovarian activity and pregnancy diagnosis were analyzed by ultrasonography. There was no difference (P>0.05) in follicular diameter (9.6 ± 0.89mm vs. 10.7 ± 1.12mm; P=0.06), in ovulation rate (90.9% vs. 90.9%; P=1) and pregnancy rate (58.8% vs. 62.9%; P=0.79), however, buffalo cows from the ECG treatment have less time between P4 removal and ovulation when compared to EBG buffalos (37.4h vs. 52.8h; P=0.001), respectively. Thus, it was concluded that the implantation of TAI in the floodplain of Amazonas is feasible and the use of EC results in successful rates, similar to EB.


2018 ◽  
Vol 53 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Marcus Vinícius Galvão Loiola ◽  
Rodrigo Freitas Bittencourt ◽  
Alexandra Soares Rodrigues ◽  
Priscila Assis Ferraz ◽  
Marcos Chalhoub Coelho Lima ◽  
...  

Abstract: The objective of this work was to evaluate the effects of supplementation with melengestrol acetate (MGA), after timed artificial insemination (TAI), on the conception rate of Nellore cows, according to cyclicity during the protocol, estrus expression between intravaginal device withdrawal and insemination, and diameter of the largest follicle at the time of insemination, in order to identify predictors of the use of MGA. Multiparous lactating cows (577) were subjected to a hormonal protocol for ovulation synchronization. On day -2 of the protocol, the animals were painted with a marker on the base of their tail. On day 0, they were evaluated for estrus expression; the preovulatory follicle diameter (POFD) was measured by ultrasonography, and the artificial insemination was performed. The animals were assigned to two experimental groups according to the supplementation or not with 0.50 mg MGA, between 13 and 18 days after TAI. Pregnancy diagnosis was performed using an ultrasound examination 35 days after TAI. A positive effect of the treatment with MGA on the conception rate occurred generally in animals in anestrus, irrespective of the estrus expression. For animals treated with MGA, only those with POFD greater than 14 mm showed better conception rates that the control group.


Author(s):  
Otávia Reis Silva ◽  
Marco Roberto Bourg de Mello ◽  
Lara Nogueira Silenciato ◽  
Joaquim Esquerdo Ferreira ◽  
Samuel Rodrigues Bonamichi do Couto ◽  
...  

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500μg of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound evaluations were performed every 12 h up to ovulation. The following reproductive parameters were evaluated: interval from intravaginal device removal to ovulation - IDO (hours); interval from ovulation to TAI-IOT (hours); diameter of the largest follicle at intravaginal device removal (mm); maximum diameter of the DF (mm) at D10; the dominant follicle growth rate (mm/day); synchronization rate - SR (%); ovulation rate - OR (%) and PR - pregnancy rate (%). Only the ovulation rate presented a statistical difference (p<0.05). In conclusion, despite the ovulation rate difference, both estradiol esters administered were effective and presented similar pregnancy rates in Girolando cows submitted to TAI.


2015 ◽  
Vol 4 (1) ◽  
pp. 356-362
Author(s):  
Josemara Silva Santos ◽  
Tania Cavalcante ◽  
Francisca Elda Ferreira Dias ◽  
Domenica Palomaris Mariano de Souza ◽  
Alencariano J.S. Falcão ◽  
...  

The objective of the experiment was to evaluate the effects of recombinant bovine somatropin (rbST), and the reuse of the progesterone (P4) releasing devices in resynchronization, on the pregnancy rates of Nellore cows submitted to fixed-time artificial insemination. A group of 123 multiparae Nellore cows, was submitted to a resynchronization protocol: on day 0 a Bovine Intravaginal Device (DIB® ) with 1,0g of P4 was implanted, associated with intramuscular administration of 2,0mg of estradiol benzoate (IM); on day 8 DIB was removed; and 1,0mg of estradiol cypionate, 0,15mg of prostaglandin F2? and 300 UI of equine chorionic gonadotropin were administered; on day 10, fixed-time artificial insemination was conducted (FTAI). The cows were randomized into G1 (n=12) – without rbST / with used Bovine Intravaginal Device, G2 (n=50) – without rbST / with new DIB, G3 (n=11) - with rbST / with used DIB and G4 (n=50) – with rbST/ with new DIB. rbST was introduced on the eighth day of the protocol. Sixty days after TAI, pregnancy diagnoses were conducted, via rectal palpation. Blood samples were taken on day 0, 8 and 10 of the protocol, in order to assess P4 plasma concentrations. Pregnancy rates were statistically evaluated through Generalized Linear Models Theory and their significance was tested with Analysis of Deviance. Pregnancy rates were 58%, 40%, 81% and 48% for G1, G2, G3 and G4, respectively, with significant statistical difference for G3. Plasma concentrations of P4 were not statistically different among groups, or collections. In view of the results obtained, we concluded that the administration of rbST in association with P4 DIB, used for the third time, improves pregnancy rates. Estrus resynchronization and re-insemination positively impacted pregnancy rates.


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