Use of color-Doppler ultrasonography for selection of recipients in timed-embryo transfer programs in beef cattle

Autor(es)

Pugliesi, Guilherme ^[1] ; de Melo, Gabriela Dalmaso ^[1] ; Silva, Julio Barboza ^{[2, 3]} ; Carvalhedo, Alexandre Sardinha ^[4] ; Lopes, Everton ^[1] ; de Siqueira Filho, Emivaldo ^[4] ; Silva, Luciano Andrade ^[2] ; Binelli, Mario ^[5]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Anim Reprod, Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Sch Anim Sci & Food Engn, Dept Vet Med, Pirassununga, SP - Brazil

^[3] Embryo Sys, Ouro Fino, MG - Brazil

^[4] Embriotec Reprod Anim, Anapolis, Go - Brazil

^[5] Univ Florida, Dept Anim Sci, Gainesville, FL 32611 - USA

• Tipo de documento: Artigo Científico
• Fonte: Theriogenology; v. 135, p. 73-79, SEP 1 2019.
• Citações Web of Science: 1

Resumo

We aimed to study the association between CL characteristics assessed by color-Doppler ultrasonography (Doppler-US) at the time of embryo transfer (ET) and pregnancy rate (P/ET) in beef recipients. Estrous cycles of crossbred beef recipients were synchronized for timed-ET. On the day of ET (Day 7), CL area, proportion of luteal blood perfusion (BP), and the relationship between the largest dominant follicle (DF) and CL (ipsilateral or contralateral) were determined. Animals (n = 444) received an in vitro produced embryo from Nelore donors, placed in the uterine horn ipsilateral to the CL. Recipients were split retrospectively in three subgroups according to CL area {[}small (<3 cm(2)), medium (3-4 cm(2)), or large (>4 cm(2))] and three subgroups according to luteal signals of BP {[}low (<= 40%), medium (45-50%) or high (>= 55%)]. Pregnancy was detected on Days 30-45 by transrectal ultrasonography and P/ET was analyzed considering the effects of cow's category (suckling or non-suckling), CL area, luteal BP and side of DF. P/ET increased along with BP category {[}low, 45.9%B, (62/135); medium, 54.1%(AB) (93/172); and high, 58.4%(A) (80/137)]. When luteal BP was evaluated as a continuous variable, a significant (P < 0.05) linear and positive effect was observed on P/ET. A greater (P < 0.05) CL area and serum progesterone concentrations were observed in the medium and high BP than in the low BP category. Although an effect of luteal size category was not significant on P/ET {[}small, 49% (76/155); medium, 59.7% (83/139); and large, 50.7% (75/148); P>0.1], when CL area was evaluated as a continuous variable, a quadratic effect (P < 0.05) indicated a positive relationship between P/ET and CL area until luteal tissue reached 4.07 cm(2), followed by a negative relationship. The location of the first-wave DF in relation to the CL did not affect P/ET (P > 0.1). In conclusion, Doppler-US is an innovative tool that has the potential to be used for selection of suitable embryo recipients based on luteal BR Selection of recipients that have a greater chance of maintaining pregnancy will increase the success of timed-ET programs. (C) 2019 Published by Elsevier Inc. (AU)

• Processo FAPESP: 16/23964-3 - Inovações no diagnóstico precoce da gestação em bovinos
• Beneficiário: Guilherme Pugliesi
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores
• Processo FAPESP: 15/10606-9 - Inovações no diagnóstico precoce da gestação em bovinos
• Beneficiário: Guilherme Pugliesi
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 17/13472-9 - Diagnóstico precoce da gestação em bovinos através da expressão de genes estimulados por interferon-tau em neutrófilos
• Beneficiário: Gabriela Dalmaso de Melo
• Modalidade de apoio: Bolsas no Brasil - Mestrado