Investigating the need for antibiotic supplementation to the extender used for semen cryopreservation in collared peccaries.

The objective was to investigate the effects of semen freezing extender supplementation with antibiotics on bacterial load of semen samples, sperm functional and morphological metrics in the collared peccary. Fresh ejaculates from 10 males were extended in Tris-egg yolk-glycerol supplemented or not (control) with gentamicin (70 µg/mL) streptomycin-penicillin (SP; 1 mg/mL-1000 IU/mL) or and cryopreserved in liquid nitrogen. Bacterial load, sperm motility patterns, morphology, membrane functionality and integrity, mitochondrial activity, chromatin integrity and sperm-binding ability were evaluated in fresh and frozen-thawed samples. Regardless of the use of antibiotics, the sole cryopreservation provoked a significant decrease (P < 0.05) in bacterial load compared to fresh samples (from average values > 1 x 106 CFU/mL to <0.4 × 106 CFU/mL). Post-thawing sperm kinetic parameters were not affected by the absence or presence of different antibiotics, except for beat cross frequency that was significantly (P < 0.05) impaired by SP supplementation compared to the group without antibiotics. After thawing, sperm morphology, membrane functionality and integrity, and mitochondrial activity were also not affected by the presence or absence of antibiotics; however, a significant decrease was observed in the group without antibiotics (P < 0.05) in comparison to fresh samples. Regarding sperm-binding ability, there were no differences among the different groups. While collared peccary semen could be efficiently cryopreserved in the absence of antibiotics in the extender, the use of both gentamicin or the streptomycin-penicillin combination is recommended as effective antibiotic supplementation for a further control of bacterial loads without affecting sperm parameters.

Composition of collared peccary seminal plasma and sperm motility kinetics in semen obtained during dry and rainy periods in a semiarid biome.

The aim of this study was to evaluate environmental effects in a semiarid region on collared peccary seminal plasma content and sperm motility. Ejaculates from 12 mature males were obtained during the peak of rainy and dry periods of the Caatinga biome. Samples were evaluated for semen volume, pH, as well as sperm concentration, morphology, osmotic response, membrane integrity, chromatin condensation, and kinetic motility. Seminal plasma was evaluated for ions and organic compounds. The values for chloride, iron, magnesium, phosphorus, citric acid, cholesterol, triglycerides, total proteins, albumin, and fructosamine were similar during the dry and rainy periods; however, concentrations of fructose (849.2 mg/dL compared with 119.4 mg/dL) and calcium (32.3 mg/dL compared with 15.6 mg/dL) were greater during the rainy compared with dry period (P < 0.05). There were correlations (P < 0.05) among values for semen variables and biochemical contents, particularly between fructose and sperm velocity average pathway (r = 0.65), velocity straight line (r = 0.78), velocity curvilinear (r = 0.57), amplitude lateral head (r = 0.62), linearity (r = 0.41), and subpopulation with a medium velocity (r = -0.75). Furthermore, values for relative humidity were positively correlated with concentrations of fructose (r = 0.49), while air temperature (r = -0.43) and wind velocity values (r = 0.66) were negatively affected by concentration of fructose (P < 0.05). There were novel results regarding collared peccary seminal plasma biochemistry indicating there are important correlations with values for semen variables that are affected by the environment in a semiarid climate.