Follicle and corpus luteum size and vascularity as predictors of fertility at the time of artificial insemination and embryo transfer in beef cattle

Abstract

Abstract:Two ultrasound based fertility prediction methods were tested prior to embryo transfer (ET) and artificial insemination (AI) in cattle. Female bovines were submitted to estrous synchronization prior to ET and AI. Animals were scanned immediately before ET and AI procedure to target follicle and corpus luteum (CL) size and vascularity. In addition, inseminated animals were also scanned eleven days after insemination to target CL size and vascularity. All data was compared with fertility by using gestational diagnosis 35 days after ovulation. Prior to ET, CL vascularity showed a positive correlation with fertility, and no pregnancy occurred in animals with less than 40% of CL vascularity. Prior to AI and also eleven days after AI, no relationship with fertility was seen in all parameters analyzed (follicle and CL size and vascularity), and contrary, cows with CL vascularity greater than 70% exhibit lower fertility. In inseminated animals, follicle size and vascularity was positive related with CL size and vascularity, as shown by the presence of greater CL size and vascularity originated from follicle with also greater size and vascularity. This is the first time that ultrasound based fertility prediction methods were tested prior to ET and AI and showed an application in ET, but not in AI programs. Further studies are needed including hormone profile evaluation to improve conclusion.

Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama)

“…Previous reports in other species have indicated that vascular development is essential for CL formation and maintenance, being luteal vascularization a requirement for an adequate P4 production and release into the general circulation (Balaro et al, ; Kanazawa et al, ). In fact, CL vascularization is associated with plasma P4 concentration and it has been proposed that it would be a good predictor of this hormone's concentration (cattle: Pinaffi et al, ; Kanazawa et al, ; Hassan et al, ; sheep: Figueira et al, ; goat: Balaro et al, ; horse: Ishak et al, ). In the present study, in both pregnant and non‐pregnant animals CL vascularization and P4 plasma concentration showed a similar profile.…”

“…Vascular development is essential for CL formation and maintenance so the impairment of this process may lead to luteal insufficiency and affect pregnancy establishment (Chouhan et al, ). In fact, in different species CL vascularization is associated with plasma P4 concentration and so it has been proposed that luteal vascularization could be a good predictor of pregnancy rates (cattle: Acosta, Hayashi, Ohtani, & Miyamoto, ; Mann, ; Pinaffi et al, ; Kanazawa et al, ; sheep: Figueira et al, ; Arashiro et al, ; goat: Balaro, Santos, Moura, Fonseca, & Brandão, ; Cosentino et al, ; horse: Ginther, Gastal, Gastal, Utt, & Beg, ; Ishak, Bashir, Gastal, & Gastal, ). Similarly, in non‐pregnant llamas, plasma P4 and CL vascularization showed a similar profile after pharmacological induction of ovulation; suggesting an association between both variables (Ulloa‐Leal, Bogle, Adams, & Ratto, ).…”

Avaliação morfofuncional do corpo lúteo para diagnóstico precoce de gestação 20 dias após IATF em vacas mestiças leiteiras

“…A ultrassonografia modo Doppler colorido pode possuir diversas vantagens aplicáveis na rotina reprodutiva, entre elas a detecção da não gestação precoce e a seleção de fêmeas para programas de sincronização e ressincronização do estro e da ovulação (Pinaffi et al 2015). Essa ferramenta mostra a vascularização em um tecido, podendo ser utilizada com a finalidade de determinar o status fisiológico das estruturas ovarianas e uterinas (Herzog & Bollwein 2007).…”

Effect of the Estrus Expression on Follicular and Luteal Morphofunctional Characteristics and Fertility in Bos indicus females Synchronized for FTAI

“…O aumento do estradiol tem sido correlacionado também com alterações funcionais nos ovários referente ao maior aporte vascular, sendo fundamental para o suprimento adequado de metabólitos responsáveis pelo crescimento, maturação e ruptura folicular [2][3][4]39]. Seguindo essa linha de pesquisa, trabalhos com a ultrassonografia modo Doppler colorido, verificaram ainda que o incremento do fluxo sanguíneo folicular estava associado com uma maior produção de estradiol.…”