ABSTRACT
This study evaluated the relationship between CL features assessed by ultrasound (luteal tissue area and blood flow, BF) or rectal palpation (size), uterine tone (UT), plasma progesterone (P4) concentration on Day 7 (D7) and subsequent pregnancy outcomes in bovine embryo recipients. A total of 163 cows and heifers were included in this study. The expected day of ovulation after the synchronization protocol was designated as D0. On D7, ovaries and uterus were examined by ultrasonography and rectal palpation, and subjective scores (1-3 scale) were assigned for CL size, area and BF, and for UT. Blood samples were collected for further P4 analysis. Each embryo recipient then received a grade I frozen-thawed in vivo-produced blastocyst, which was transferred to the uterine horn ipsilateral to the CL. Pregnancy diagnosis was performed on D35, and the results were retrospectively compared with the assigned scores for CL and UT. We observed a significant (p < .02) interaction between CL size and UT, with a progressive increase in the likelihood of pregnancy for recipients bearing a large CL among those with turgid UT. Ultrasound scoring of the CL using B-mode and Doppler-mode did not significantly predict pregnancy rates on D35 (p < .6 and p < .5, respectively). However, logistic regression analysis revealed a trend towards a quadratic effect (p < .08 and p < .06) indicating that the probability of pregnancy varied according to the area of luteal tissue and P4 concentrations, respectively. No significant (p > .05) association was found between the probability of pregnancy and the BF area of the CL. In summary, UT before embryo transfer may reflect successful recipient synchronization. Elevated P4 levels, assessed by CL size, may offset uterine contractility, mitigating adverse effects. Additionally, the CL area may be more important than its vascularization area when evaluating recipients D7 after ovulation.
Subject(s)
Embryo Transfer , Progesterone , Uterus , Female , Animals , Cattle/physiology , Embryo Transfer/veterinary , Pregnancy , Uterus/blood supply , Uterus/diagnostic imaging , Progesterone/blood , Ultrasonography/veterinary , Corpus Luteum/physiology , Pregnancy Rate , Estrus Synchronization , Pregnancy Outcome/veterinaryABSTRACT
Avaliou-se a sincronização folicular e vascularização na parede do folículo dominante (FD) após o tratamento com Cipionato (CE) ou Benzoato de estradiol (BE). No Experimento 1, 45 novilhas receberam implante de P4 (1,0g) e foram distribuídas em 3 grupos de acordo com éster de estradiol administrado pela via intramuscular: 1mL salina; 0,5mg CE ou 2,0mg BE. O diâmetro do FD e a emergência folicular (EF) foram monitorados por 5 dias. No experimento 2, D0 (dia 0): 30 novilhas receberam implante de P4 e 2,0mg BE; D8, retirada do implante e 0,5mg de prostaglandina (cloprostenol); D9: tratamentos: 1mL salina; 0,5mg CE ou 1,0mg BE. O diâmetro e a vascularização do FD foram monitorados do D8 ao D10. Os dados foram analisados por ANOVA ou Kruskal-Wallis, e as médias comparadas por Tukey (5%). No experimento 1, a EF ocorreu mais tarde (P 0,0013) no grupo BE (4,3±0,8 vs. 3,5±0,8d). No experimento 2, o fluxo sanguíneo do FD aumentou (P 0,001) 24h após o tratamento com BE. A taxa de ovulação foi semelhante (P>0,05) entre os grupos (80,0, 70,0 e 55,5%, BE, CE e salina). Conclui-se que nas concentrações utilizadas, o BE, no início do protocolo, retardou a EF e, no final do protocolo, promoveu uma melhor sincronia do FD demonstrada pela elevação do fluxo sanguíneo.
The study aimed to evaluate synchronization and blood flow of the dominant follicle (DF) after estradiol cypionate (EC) or benzoate(EB) treatment. In experiment 1, progesterone (P4) implants (1.0g) were inserted in 45 heifers, which were given 1mL saline,0.5mg EC or 2.0mg EB. The diameter of the DF and follicle emergence (FE) were recorded for 5 days. For experiment 2, 30 heiferswere given: D0 (day 0): P4 implant and 2.0mg EB; D8: implant removal and 0.5mg of prostaglandin (cloprostenol). On D9, theywere assigned in 1mL saline, 0.5mg EC or 1.0mg EB. From D8 to D10, the diameter and blood flow of the DF was monitored.Data were analyzed by ANOVA or Kruskal-Wallis test, and compared by Tukey (5%). In experiment 1, the FE occurred later(P0.05) between groups (80.0, 70.0 and 55.5%, EB, EC and saline). The interpretation was that,in these concentrations, the EB, at the beginning, delayed FE and, at the end of the protocol, promoted a better synchrony of theDF, confirmed by the increase of the blood flow.
