Uso de sacarose como suplemento em diluidor para criopreservação de sêmen de garanhões

Abstract

The objective of the study was to investigate the effects of different concentrations of sucrose on equine semen quality after thawing. Twenty-four ejaculates were obtained from 6 Mangalarga Marchador and Campolina stallions, in which each ejaculate was divided into 5 groups: control (freezing diluent without sucrose), positive control (Botucrio®®) and three groups consisting of the freezing diluent supplemented with Saccharose at concentrations of 25 mM, 50 mM and 100 mM. The semen samples were obtained with artificial vagina, evaluated and transported (5 ºC) to the laboratory. The semen samples were diluted (200x106 sperm / mL), packed in vales and subjected to freezing. Immediately after thawing (37 ° C, 30s), the semen samples were evaluated for kinetics, plasma and acrosomal membrane integrity, membrane stability and mitochondrial membrane potential. The addition of 50 and 100 mM sucrose to the freezing diluent increased (P <0.05) the MT, MP, VCL, VSL and VAP parameters in relation to the control group. The WOB parameter of the group supplemented with 100 mM sucrose concentration was higher (P <0.05) than the control group. Higher values ​​(P <0.05) of HLA and BCF were observed in the sucrose-treated groups (25, 50 and 100 mM) compared to Botucrio®. Frozen semen in the presence of 100 mM sucrose had higher percentages (P <0.05) of spermatozoa with intact plasma and acrosomal membranes (PNA- / IP-), and high mitochondrial membrane potential (APMM) when compared to frozen semen without sucrose (control group), with Botucrio® (positive control). It is concluded that the addition of sucrose at concentrations of 50 and 100 mM to the milk / yolk diluent can be an efficient cryoprotectant for freezing equine semen.