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18 results on '"Prata, Alexandre B."'

8. 279 ReBreed21, a Rapid Reinsemination Program: Fertility in Bos Indicus Cattle of Different Parities

Author

Andrade, João Paulo N, primary, Monteiro, Pedro L, additional, Prata, Alexandre B, additional, Robl, Adelino, additional, Leite, José, additional, Pimenta, Cesar, additional, Dias, José, additional, Guimarães, Afonso, additional, Lippe, Beatriz, additional, Ribeiro, Heuller, additional, Merhi, Same, additional, Hartmann, Diego, additional, Sartori, Roberto, additional, and Wiltbank, Milo C, additional

Published
2021
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9. Effects of feeding rumen-protected methionine pre- and postpartum on reproductive outcomes of multiparous Holstein cows

Author

Stangaferro, Matias L., primary, Toledo, Mateus Z., additional, Gennari, Rodrigo S., additional, Perez, Martin M., additional, Gamarra, Caio A., additional, Sitko, Emily M., additional, Monteiro, Pedro L.J., additional, Masello, Magdalena, additional, Prata, Alexandre B., additional, Granados, German E., additional, Van Amburgh, Michael E., additional, Luchini, Daniel, additional, Shaver, Randy D., additional, Wiltbank, Milo C., additional, and Giordano, Julio O., additional

Published
2021
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10. 141 Effect of induction of an ipsilateral vs. contralateral accessory corpus luteum (CL) on pregnancy per AI and pregnancy loss in lactating dairy cows

Author

Monteiro, Pedro L J, primary, Gamarra, Caio A, additional, Genari, Rodrigo S, additional, Prata, Alexandre B, additional, Barletta, Rafael V, additional, Duran, Peregrino, additional, Ochoa, Julian C, additional, Canavessi, Aurea M O, additional, Sartori, Roberto, additional, and Wiltbank, Milo C, additional

Published
2020
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11. Interactions of circulating estradiol and progesterone on changes in endometrial area and pituitary responsiveness to GnRH†

Author

Motta, Jessica C L, primary, Madureira, Guilherme, additional, Silva, Lucas O, additional, Alves, Rodrigo L O R, additional, Silvestri, Mayara, additional, Drum, Jéssica N, additional, Consentini, Carlos E C, additional, Prata, Alexandre B, additional, Pohler, Ky G, additional, Wiltbank, Milo C, additional, and Sartori, Roberto, additional

Published
2020
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16. Oxytocin-induced prostaglandin F2-alpha release is low in early bovine pregnancy but increases during the second month of pregnancy†.

Author

Drum, Jéssica N, Wiltbank, Milo C, Monteiro, Pedro L J, Prata, Alexandre B, Gennari, Rodrigo S, Gamarra, Caio A, Canavessi, Aurea M O, and Sartori, Roberto

Abstract

Circulating prostaglandin F2α metabolite (PGFM) after an oxytocin challenge was evaluated throughout the first 2 months of pregnancy in lactating Holstein cows. On day 11, 18, and 25 after artificial insemination (AI), and on days 32, 39, 46, 53, and 60 of pregnancy, cows were challenged with 50 IU oxytocin, i.m. Blood was collected before (0 min), 30, 60, 90, and 120 min after oxytocin for plasma PGFM concentrations. Ultrasound evaluations were performed for pregnancy diagnosis on day 32-60 post-AI. Nonpregnant (NP) cows on day 18 were designated by a lack of interferon-stimulated genes in peripheral blood leukocytes and Pregnant (P) based on day 32 ultrasound. On day 11, P and NP were similar with low PGFM and no effect of oxytocin on PGFM. On day 18, oxytocin increased PGFM (3-fold) in NP with little change in P cows. Comparing only P cows from day 11 to 60, basal circulating PGFM increased as pregnancy progressed, with day 11 and 18, lower than all days from day 25 to 60 of pregnancy. Oxytocin-induced PGFM in P cows on day 25 was greater than P cows on day 18 (2.9-fold). However, oxytocin-induced PGFM was lower on day 25 compared to day 53 and 60, with intermediate values on day 32, 39, and 46 of pregnancy. Thus, the corpus luteum (CL) of early pregnancy (day 11, 18) is maintained by suppression of PGF, as reflected by suppressed PGFM in this study. However, during the second month of pregnancy, uterine PGF secretion was not suppressed since basal PGFM and oxytocin-induced PGFM secretion were elevated. Apparently, mechanisms other than suppression of oxytocin receptors maintain CL after day 25 of pregnancy.

Published
2020
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18. ReBreed21, a Rapid Reinsemination Program: Fertility in Bos Indicus Cattle of Different Parities.

Author

Andrade, João Paulo N., Monteiro, Pedro L., Prata, Alexandre B., Robl, Adelino, Leite, José, Pimenta, Cesar, Dias, José, Guimarães, Afonso, Lippe, Beatriz, Ribeiro, Heuller, Merhi, Same, Hartmann, Diego, Sartori, Roberto, and Wiltbank, Milo C.

Subjects
ZEBUS, CATTLE fertility, CATTLE crossbreeding, CATTLE, DOPPLER ultrasonography, FERTILITY, BLOOD flow
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. [ABSTRACT FROM AUTHOR]

Published
2021

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