Efeito do momento da onda folicular sobre potenciais preditores de fertilidade e suas repetibilidades em novilhas pré-púberes Bos indicus (Nelore) e Bos taurus (Caracu)
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Data
2022-07-22
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Universidade Estadual Paulista (Unesp)
Resumo
O estudo foi delineado para avaliar o efeito dos momentos da onda folicular (emergência e dominância) e a repetibilidade de potenciais preditores de fertilidade (morfometria vulvar, biometria, ecogenicidade e ecotextura uterina, biometria ovariana e contagem de folículos antrais – CFA) em novilhas pré-púberes de subespécies diferentes. Novilhas Nelore (n = 30) e Caracu (n = 28) foram submetidas a uma sequência de onze avaliações a cada 48 horas (D0 – dia aleatório da onda folicular antral, até D20) para estudar os potenciais preditores de fertilidade em condições naturais. Os dados obtidos foram comparados de acordo com a raça e o momento da onda folicular. A análise estatística incluiu efeitos fixos de dias de avaliação, raças e sua interação estatística, e foi realizada pelos procedimentos MIXED, GENMOD, GLM e CORR do programa estatístico SAS (P < 0,05). Os coeficientes de repetibilidade e as correlações de Pearson das variáveis também foram calculados. A raça mostrou influenciar a altura de rima, a área ovariana e a CFA, que foram maiores nas novilhas Nelore (P < 0,02). O momento da onda folicular também influenciou a maioria das avaliações, com destaque para a CFA, que se mostrou maior na presença de folículo dominante (FD) em ambas as raças (P < 0,0001). O coeficiente de repetibilidade foi considerado alto para a largura vulvar (0,76 e 0,66), a área ovariana (0,70 e 0,62) e a CFA (0,76 e 0,74) nas raças Nelore e Caracu, respectivamente. Apenas a biometria ovariana foi capaz de predizer a CFA (valores das correlações de Pearson acima de 0,66; P < 0,0001) em novilhas pré-púberes. Os resultados descritos mostram que, mesmo influenciados pelo momento da onda folicular e pela raça, uma única medida ao longo da pré-puberdade da maioria dos preditores de fertilidade é suficiente para caracterizar novilhas pré-púberes.
The study evaluated the effects of follicular wave moments (emergence and dominance) and the repeatability of potential fertility predictors (vulvar morphometry, uterine biometry, echogenicity and echotexture, ovarian biometry and antral follicle count – AFC) in two purebred prepubertal heifers. Nellore (n = 30) and Caracu (n = 28) heifers were submitted to a sequence of eleven evaluation days conducted every 48 hours (D0 – random day of the antral follicular wave, until D20) to study the potential fertility indicators under natural conditions. The data obtained were compared according to breed and to follicular wave moment. Statistical analysis included fixed effects of breeds, evaluation days and their statistical interaction, being performed by MIXED, GENMOD, GLM and CORR procedures of the SAS statistical program (P < 0.05). Repeatability coefficients and Pearson’s correlations of the variables were also calculated. Breed was shown to influence rima height, ovarian area and AFC, which were greater in Nellore heifers (P < 0.02). The follicular wave moment also influenced most of the evaluations, highlighting the AFC, which showed to be greater in the dominant follicle (DF) presence in both breeds (P < 0.0001). The repeatability coefficient was considered high for vulva width (0.76 and 0.66), ovarian area (0.70 and 0.62) and AFC (0.76 and 0.74) for Nellore and Caracu breeds, respectively. Only ovarian biometry was able to predict AFC (Pearson’s correlations values above 0.66; P < 0.0001) in prepubertal heifers. The results described show that, even influenced by follicular wave moment and breed, a single measurement throughout prepuberty of most fertility predictors is sufficient to characterize prepubertal heifers.
The study evaluated the effects of follicular wave moments (emergence and dominance) and the repeatability of potential fertility predictors (vulvar morphometry, uterine biometry, echogenicity and echotexture, ovarian biometry and antral follicle count – AFC) in two purebred prepubertal heifers. Nellore (n = 30) and Caracu (n = 28) heifers were submitted to a sequence of eleven evaluation days conducted every 48 hours (D0 – random day of the antral follicular wave, until D20) to study the potential fertility indicators under natural conditions. The data obtained were compared according to breed and to follicular wave moment. Statistical analysis included fixed effects of breeds, evaluation days and their statistical interaction, being performed by MIXED, GENMOD, GLM and CORR procedures of the SAS statistical program (P < 0.05). Repeatability coefficients and Pearson’s correlations of the variables were also calculated. Breed was shown to influence rima height, ovarian area and AFC, which were greater in Nellore heifers (P < 0.02). The follicular wave moment also influenced most of the evaluations, highlighting the AFC, which showed to be greater in the dominant follicle (DF) presence in both breeds (P < 0.0001). The repeatability coefficient was considered high for vulva width (0.76 and 0.66), ovarian area (0.70 and 0.62) and AFC (0.76 and 0.74) for Nellore and Caracu breeds, respectively. Only ovarian biometry was able to predict AFC (Pearson’s correlations values above 0.66; P < 0.0001) in prepubertal heifers. The results described show that, even influenced by follicular wave moment and breed, a single measurement throughout prepuberty of most fertility predictors is sufficient to characterize prepubertal heifers.
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Reprodução, Bovinos, Folículo ovariano, Ultrassonografia veterinária