Fecha/hora: 06/06/2024 12:06:26

Biblioteca(s): | INIA Las Brujas.
Fecha corriente: | 15/06/2022
Fecha de la última actualización: | 15/06/2022
Autoria: | TSCHOPP, J.C.; MACAGNO, A.J.; MAPLETOFT, R.J.; MENCHACA, A.; BÓ, G. A.
Afiliación: | JUAN CARLOS TSCHOPP, Instituto de Reproducción Animal Córdoba (IRAC), Córdoba, Argentina; Instituto A.P. de Ciencias Básicas y Aplicadas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa del Rosario, Córdoba, Argentina; ALEJANDRO J. MACAGNO, Instituto de Reproducción Animal Córdoba (IRAC), Córdoba, Argentina; Instituto A.P. de Ciencias Básicas y Aplicadas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa del Rosario, Córdoba, Argentina; REUBEN J. MAPLETOFT, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada; JOSE ALEJO MENCHACA BARBEITO, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Montevideo, Uruguay; GABRIEL A. BÓ, Instituto de Reproducción Animal Córdoba (IRAC), Córdoba, Argentina; Instituto A.P. de Ciencias Básicas y Aplicadas, Medicina Veterinaria, Universidad Nacional de Villa María, Villa del Rosario, Córdoba, Argentina.
Título: | Effect of the addition of GnRH and a second prostaglandin F2&#945; treatment on pregnancy per artificial insemination in lactating dairy cows submitted to an estradiol/progesterone-based timed-AI protocol.
Año de publicación: | 2022
Fuente/Imprenta: | Theriogenology, 2022, Volume 188, Pages 63-70. doi: https://doi.org/10.1016/j.theriogenology.2022.05.019
ISSN: | 0093-691X
DOI: | 10.1016/j.theriogenology.2022.05.019
Idioma: | Inglés

Notas:

Article history: Received 23 February 2022; Received in revised form 23 May 2022; Accepted 24 May 2022; Available online 27 May 2022; To be published August 2022.
Corresponding author: Bó, G.A.; Instituto de Reproducción Animal Córdoba (IRAC), Zona Rural General Paz, Córdoba, Uruguay; email:gabrielbo62@gmail.com  -- 
This research was supported by Fondo Nacional de Ciencia y Tecnología (FONCYT PICT 2017?4550), Instituto de Investigación Universidad Nacional de Villa María (UNVM), and Instituto de Reproducción Animal de Córdoba (IRAC).

Contenido: | ABSTRACT - Two experiments determined whether the addition of GnRH at the beginning of an estradiol (E2)/progesterone (P4)- based synchronization protocol and/or a second dose of prostaglandin F2&#945; (PGF2&#945;) the day before P4 device removal improves pregnancy rate in lactating dairy cows. On Day 0, all cows received a CIDR-B device and 2 mg i.m. estradiol benzoate, and half received 200 &#956;g i.m. gonadorelin acetate (GnRH). On Day 7, cows were further subdivided to receive PGF2&#945; (500 &#956;g i.m. cloprostenol) or no PGF2&#945; treatment. On Day 8, CIDR-B were removed, and all cows received PGF2&#945;, 1 mg estradiol cypionate and 400 IU eCG i.m., and an estrus detection aid. Experiment 1 was designed to evaluate the effect of treatments on follicular development from P4 device removal to ovulation, expression of estrus, time of ovulation and serum P4 concentrations. Cows (n = 76) were examined by ultrasonography and bled for serum P4 determinations every 12 h from the time of P4 device removal but were not inseminated. In Experiment 2, all cows (n = 1036) were inseminated based on estrus detection using tail-paint. Cows with >50% of the paint rubbed-off by 48 h after P4 device removal were inseminated at that time, whereas those not in estrus received 100 &#956;g i.m. of GnRH and were inseminated 12 h later. In Experiment 1, the interval from P4 device removal to ovulation was 71.7 ± 1.5 h and did not differ among groups. However, cows that received 2 injections of PGF2&#945; had a greater (P < 0.01) estrus rate and lower (P < 0.01) P4 concentrations at 48 h after P4 device removal than those that received 1 PGF2&#945; (estrus rate: 86.8% vs 68.4% and P4 concentration: 0.12 ± 0.01 vs 0.36 ± 0.07, for 2 and 1 PGF2&#945;, respectively). In Experiment 2, estrus rate was also influenced by the number of PGF2&#945; treatments, regardless of whether cows received or did not receive GnRH on Day 0 (2 PGF2&#945;: 84.7%, 438/517 vs 1 PGF2&#945;: 65.7%, 341/519; P < 0.01). Furthermore, there was a GnRH treatment by number of PGF2&#945; treatments interaction (P < 0.05) on P/AI that was attributed to greater (P < 0.05) P/AI in cows that received GnRH on Day 0 and 2 PGF2&#945; than in the other three treatment groups (EB+1 PGF2&#945;: 45.2%, 119/263; EB+2 PGF2&#945;: 45.8%, 119/260; EB + GnRH + 1 PGF2&#945;: 45.7%, 117/256 and EB + GnRH + 2 PGF2&#945;: 57.2%, 147/257). It was concluded that the addition of GnRH on Day 0 and a second dose of PGF2&#945; the day before P4 device removal improves P/AI in lactating dairy cows synchronized with an estradiol/P4-based protocol. © 2022 Elsevier Inc.
Palabras-Clave: | Dairy cows; Estrus; GnRH; Ovulation; PLATAFORMA DE SALUD ANIMAL; Timed-AI.
Categoría del tema: | L10 Genética y mejoramiento animal
Registro original: | INIA Las Brujas (LB)
Ejemplares: | LB - (103102-1) - PXI - AP - DD - Theriogenology/2022 -  -  - DIS