279 ReBreed21, a Rapid Reinsemination Program: Fertility in Bos Indicus Cattle of Different Parities

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 145-146
Author(s):  
João Paulo N Andrade ◽  
Pedro L Monteiro ◽  
Alexandre B Prata ◽  
Adelino Robl ◽  
José Leite ◽  
...  

Abstract This study evaluated efficiency of a reinsemination program allowing timed AI (TAI) every 21 days (ReBreed21; RB21) vs. a traditional Resynch program in Nellore females (n = 2,085) of different parities. First TAI followed estradiol (E2)/progesterone (P4)-based synchronization, and was considered d0. For RB21 (n= 1,357), cows received P4 insert on D12. On D19, P4 was removed, followed by treatment with equine chorionic gonadotropin (eCG) and 0.6 mg E2 Cypionate (RB21+EC, n = 60) or nothing (RB21, n=687). On D21, Doppler ultrasound was used to determine CL blood flow [< 25%=nonpregnant (NP)] and NP cows received TAI immediately together with 25µg licerelin acetate (GnRH). A second RB21 program using the same groups was done in cows that received TAI on D21 to allow a third potential TAI on D42. Pregnancy diagnosis was performed on D33 after each TAI. Cows designated pregnant on D21 but NP on D33, were termed False-Positive (FP). On D33, all control (n = 728) designated NP and FP cows were resynchronized with P4+E2 protocol for the second TAI at D42. Data were analyzed with SAS and shown in Table 1. For all cows, there were no differences in the three groups (Control, RB21, RB21+EC) for pregnancy/AI (P/AI). In nulliparous heifers, cumulative pregnancies were greater for both RB21 groups compared to Controls at D21 or D42 of the breeding season. Primiparous cows had greater cumulative pregnancies at D21 but not D42. Primiparous cows at second TAI had lower P/AI in RB21 (34.2%) vs. Control (51.7%); however, RB21-EC (55.8%) was similar to Control. No other parities had differences between RB21 and RB21+EC. Multiparous cows had high fertility at first TAI [69.3% (418/603)] and no differences between groups in cumulative pregnancies (P = 0.23). Thus, ReBreed21 program increases the reproductive efficiency in Nulliparous and Primiparous but not Multiparous Bos Indicus cattle. Adding EC to RB21 program only improves P/AI in Primiparous cows.

2019 ◽  
Vol 31 (1) ◽  
pp. 134
Author(s):  
L. M. S. Simões ◽  
E. A. Lima ◽  
A. P. C. Santos ◽  
R. E. Orlandi ◽  
M. P. Bottino ◽  
...  

The objective was to determine the incidence of false-positive pregnancy diagnosis following the use of colour Doppler ultrasonography 20 and 22 days after fixed-time AI (FTAI) in Bos indicus heifers submitted to resynchronization 14 days after first FTAI. In the study, 512 Nellore heifers at 24.5±0.8 months of age and body condition score of 3.4±0.1 were used beginning 14 days after FTAI. On Day 14, heifers received 50mg of short-acting progesterone (Afisterone®, CEVA, São Paulo, Brazil) and a progesterone device (Prociclar®, CEVA). Eight days later (Day 22), the progesterone device was removed. A duplex B-mode (grayscale) and pulse-wave colour Doppler ultrasound instrument (M5, Mindray, Shenzhen, China) equipped with a multifrequency linear transducer was used for the examination of luteal blood flow on Days 20 and 22. The percentage of luteal area with colour Doppler signals of blood flow at each examination was determined as previously described (Ginther 2007) and was classified as low [corpus luteum (CL) with less than 25% vascularized area], intermediate (CL with 25-75% vascularized area), or high (CL with more than 75% vascularized area). Heifers with intermediate and high luteal blood flow were diagnosed as pregnant by Doppler ultrasonography, and heifers with low luteal blood flow were diagnosed as nonpregnant. Heifers diagnosed as pregnant by Doppler ultrasonography were examined 30 days after FTAI by B-mode ultrasound examination for pregnancy diagnosis and to determine the number of false positives (heifers pregnant by Doppler ultrasonography and nonpregnant by B-mode ultrasonography). Statistical analysis was performed by the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). Pregnancy rate by Doppler ultrasonography [Day 20=60.5% (310/512), Day 22=55.3% (283/512); P=0.10] and false-positive percentage [Day 20=29.7% (92/310), Day 22=23.0% (65/2830); P=0.06] were similar on pregnancy diagnoses by Doppler ultrasonography performed 20 and 22 days after FTAI. Furthermore, in the period from 20 to 22 days after FTAI, luteolysis was verified in 5.8% (30/512) of heifers. In conclusion, anticipation of pregnancy diagnosis in 2 days by evaluation of luteal blood flow with colour Doppler ultrasonography (20 days after FTAI) does not interfere with pregnancy rate by Doppler ultrasound and percentage of false positives in Bos indicus heifers.


2019 ◽  
Vol 59 (2) ◽  
pp. 225 ◽  
Author(s):  
Walvonvitis Baes Rodrigues ◽  
Jean do Prado Jara ◽  
Juliana Correa Borges ◽  
Luiz Orcirio Fialho de Oliveira ◽  
Urbano Pinto Gomes de Abreu ◽  
...  

The objective of this trial was to evaluate different post-timed artificial insemination (TAI) reproductive managements in postpartum beef cows to produce crossbred calves from artificial insemination (AI). Nellore cows (n = 607), with 45 days postpartum, were inseminated at a fixed time, using a protocol that included an intravaginal progesterone-releasing device along with oestradiol benzoate, prostaglandin, equine chorionic gonadotropin, and oestradiol cypionate, followed TAI 48 h post-device removal. Four post-TAI treatments were evaluated: in CONTROL (T1, n = 161), cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). In OBSERVATION (T2, n = 132), heat detection was performed for 15–25 days post-TAI, followed by AI. In RESYNC22 (T3, n = 157) and RESYNC30 (T4, n = 157), resynchronisation started after 22 or 30 days, following second TAI at Day 32 or 40 days after first TAI. In T2, T3 and T4, after the second AI, cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). The pregnancy rate (PR) for the first TAI did not differ (54.6%, 53.0%, 59.2%, and 51.6% for CONTROL, OBSERVATION, RESYNC 22, and RESYNC 30, respectively; P = 0.66), and no difference was observed for the second TAI (RESYNC 22 = 45.31% and RESYNC30 = 46.05%; P = 0.137), in the PR at the end of the breeding season (86.33%, 86.36%, 78.98%, and 81.52%, P = 0.43), or embryonic losses (4.54%, 2.85%, 6.45% and 7.40%, respectively; P = 0.61), but the percentage of crossbred pregnancy was higher in groups with resynchronisation (RESYNC22 and RESYNC30) than CONTROL and OBSERVATION (98.38%, 90.62%, 63.30%, 78.95%, P < 0.001). In conclusion, resynchronisation programs of 22 or 30 days are more efficient to produce AI products, and the final pregnancy rate is similar among the treatments, differing only in the amount of calves produced by AI.


2018 ◽  
Vol 196 ◽  
pp. 28-34 ◽  
Author(s):  
Abdul Saboor Khan ◽  
Muhammad Shafiq Haider ◽  
Mubbashar Hassan ◽  
Ali Husnain ◽  
Muhammad Rizwan Yousuf ◽  
...  

2010 ◽  
Vol 118 (2-4) ◽  
pp. 182-187 ◽  
Author(s):  
M.F. Sá Filho ◽  
J.R.S. Torres-Júnior ◽  
L. Penteado ◽  
L.U. Gimenes ◽  
R.M. Ferreira ◽  
...  

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Karin Markenroth Bloch ◽  
Fabian Kording ◽  
Johannes Töger

Abstract Background Ultra-high field magnetic resonance imaging (MR) may be used to improve intracranial blood flow measurements. However, standard cardiac synchronization methods tend to fail at ultra-high field MR. Therefore, this study aims to investigate an alternative synchronization technique using Doppler ultrasound. Methods Healthy subjects (n = 9) were examined with 7T MR. Flow was measured in the M1-branch of the middle cerebral artery (MCA) and in the cerebral aqueduct (CA) using through-plane phase contrast (2D flow). Flow in the circle of Willis was measured with three-dimensional, three-directional phase contrast (4D flow). Scans were gated with Doppler ultrasound (DUS) and electrocardiogram (ECG), and pulse oximetry data (POX) was collected simultaneously. False negative and false positive trigger events were counted for ECG, DUS and POX, and quantitative flow measures were compared. Results There were fewer false positive triggers for DUS compared to ECG (5.3 ± 11 vs. 25 ± 31, p = 0.031), while no other measured parameters differed significantly. Net blood flow in M1 was similar between DUS and ECG for 2D flow (1.5 ± 0.39 vs. 1.6 ± 0.41, bias ± 1.96SD: − 0.021 ± 0.36) and 4D flow (1.8 ± 0.48 vs. 9 ± 0.59, bias ± 1.96SD: − 0.086 ± 0.57 ml). Net CSF flow per heart beat in the CA was also similar for DUS and ECG (3.6 ± 2.1 vs. 3.0 ± 5.8, bias ± 1.96SD: 0.61 ± 13.6 μl). Conclusion Gating with DUS produced fewer false trigger events than using ECG, with similar quantitative flow values. DUS gating is a promising technique for cardiac synchronization at 7T.


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