ABSTRACT
Around 60-80% of oocytes maturated in vivo reached competence, while the proportion of maturation in vitro is rarely higher than 40%. In this sense, butafosfan has been used in vivo to improve metabolic condition of postpartum cows, and can represent an alternative to increase reproductive efficiency in cows. The aim of this study was to evaluate the addition of increasing doses of butafosfan during oocyte maturation in vitro on the initial embryo development in cattle. In total, 1400 cumulus-oocyte complexes (COCs) were distributed in four groups and maturated according to supplementation with increasing concentrations of butafosfan (0 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml). Then, 20 oocytes per group were collected to evaluate nuclear maturation and gene expression on cumulus cells and oocytes and the remaining oocytes were inseminated and cultured until day 7, when blastocysts were collected for gene expression analysis. A dose-dependent effect of butafosfan was observed, with decrease of cleavage rate and embryo development with higher doses. No difference between groups was observed in maturation rate and expression of genes related to oocyte quality. Our results suggest that butafosfan is prejudicial for oocytes, compromising cleavage and embryo development.
Subject(s)
Blastocyst/physiology , Butylamines/pharmacology , In Vitro Oocyte Maturation Techniques/veterinary , Oocytes/drug effects , Phosphinic Acids/pharmacology , Animals , Butylamines/administration & dosage , Cattle , Dose-Response Relationship, Drug , Female , Fertilization in Vitro , Gene Expression Regulation, Developmental/drug effects , In Vitro Oocyte Maturation Techniques/methods , Oocytes/physiology , Phosphinic Acids/administration & dosageABSTRACT
O objetivo, com este estudo, foi investigar as conseqüências da hipomagnesemia subclínica sobre parâmetros metabólicos de vacas leiteiras. Amostras de sangue foram coletadas de 12 animais, a cada dois dias, entre os dias 22 pré e 22 pós-parto, para a realização de análises sanguíneas e determinação do perfil metabólico. Os animais foram categorizados de acordo com os níveis séricos de magnésio: Grupo Hipomagnesêmicas (n=5), com níveis abaixo de 1,8 mg/dL em ao menos dois dias consecutivos, e o Grupo Controle (n=7), com níveis acima de 1,8 mg/dL em todo o período. O grupo hipomagnesêmicas apresentou níveis de glucagon maiores nos dias 10, 18 e 20, e a taxa Glucagon/Insulina foi maior nos dias 6, 8, 10, 12 e 16 após o parto. As concentrações de aspartato amino transferase foram maiores no grupo hipomagnesêmicas nos dias 0, 6, 8, 10, 12 e 14 pós-parto. Os resultados indicaram que níveis reduzidos de magnésio no periparto podem estar relacionados com níveis elevados de aspartato amino transferase e de glucagon. Em geral, a hipomagnesemia subclínica não altera os níveis dos indicadores do metabolismo energético, mas os resultados demonstraram que as vacas com hipomagnesemia apresentaram maior taxa de glucagon/insulina, demonstrando um maior desafio para manter os níveis glicêmicos.
