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http://acervodigital.unesp.br/handle/11449/69517
- Title:
- The effect of type of vaginal insert and dose of pLH on embryo production, following fixed-time AI in a progestin-based superstimulatory protocol in Nelore cattle
- Universidade Estadual Paulista (UNESP)
- Fazenda Nova América
- 0093-691X
- The objective was to analyze and report field data focusing on the effect of type of progesterone-releasing vaginal insert and dose of pLH on embryo production, following a superstimulatory protocol involving fixed-time artificial insemination (FTAI) in Nelore cattle (Bos taurus indicus). Donor heifers and cows (n = 68; 136 superstimulations over 2 years) received an intravaginal, progesterone-releasing insert (CIDR® or DIB®, with 1.9 or 1.0 g progesterone, respectively) and 3-4 mg of estradiol benzoate (EB) i.m. at random stages of the estrous cycle. Five days later (designated Day 0), cattle were superstimulated with a total of 120-200 mg of pFSH (Folltropin-V®), given twice daily in decreasing doses from Days 0 to 3. All cattle received two luteolytic doses of PGF2α at 08:00 and 20:00 h on Day 2 and progesterone inserts were removed at 20:00 h on Day 3 (36 h after the first PGF2α injection). Ovulation was induced with pLH (Lutropin-V®, 12.5 or 25 mg, i.m.) at 08:00 h on Day 4 with FTAI 12, 24 and in several cases, 36 h later. Embryos were recovered on Days 11 or 12, graded and transferred to synchronous recipients. Overall, the mean (±S.E.M.) number of total ova/embryos (13.3 ± 0.8) and viable embryos (9.4 ± 0.6) and pregnancy rate (43.5%; 528/1213) did not differ among groups, but embryo viability rate (overall, 70.8%) was higher in donors with a DIB (72.3%) than a CIDR (68.3%, P = 0.007). In conclusion, the administration of pLH 12 h after progesterone removal in a progestin-based superstimulatory protocol facilitated fixed-time AI in Nelore donors, with embryo production, embryo viability and pregnancy rates after embryo transfer, comparable to published results where estrus detection and AI was done. Results suggested a possible alternative, which would eliminate the need for estrus detection in donors. © 2006 Elsevier Inc. All rights reserved.
- 1-Feb-2007
- Theriogenology, v. 67, n. 3, p. 655-660, 2007.
- 655-660
- Bovine
- Embryo transfer
- pLH
- Progesterone
- Superovulation
- gestagen
- hormone
- luteinizing hormone
- animal
- animal disease
- artificial insemination
- cattle
- clinical trial
- drug effect
- embryo (anatomy)
- female
- intravaginal drug administration
- methodology
- ovulation induction
- physiology
- pregnancy
- pregnancy rate
- reproduction
- Administration, Intravaginal
- Animals
- Cattle
- Embryo, Mammalian
- Female
- Hormones
- Insemination, Artificial
- Luteinizing Hormone
- Ovulation Induction
- Pregnancy
- Pregnancy Rate
- Progestins
- Reproduction
- Bos indicus
- Bos taurus
- http://dx.doi.org/10.1016/j.theriogenology.2006.10.001
- Acesso restrito
- outro
- http://repositorio.unesp.br/handle/11449/69517 Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp
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