Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.

Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.(AU)

Low density lipoproteins at 2% concentration can replace whole egg yolk in tes-tris-milk extender for freezing buffalo sperm cells

Background: Over the years, the most commonly used extenders for semen cryopreservation contain egg yolk as cryoprotectant. However, more recent studies have used the low density lipoproteins, extract of hen egg yolk which is responsible for the cryoprotective effect. Nevertheless, little was known about its required minimum concentration as well as its interaction with other extra cellular cryoprotectants, like skimmed milk. The present study aimed at investigating the effect of replacing whole egg yolk by adding low density lipoproteins at low concentrations, in TES-Tris-skim milk based extender, on the post-thaw quality of buffalo bull sperm.Materials, Methods & Results: Eighteen ejaculates were collected from six buffalo bulls and diluted with TES-Tris-skim milk based extender containing LDL, extracted from hen egg yolks, at the concentrations of 2%, 4%, 8% and 14%, against a control extender containing 20% fresh egg yolk. After semen collection, analyses of subjective motility, vigor, force tourbillon, sperm concentration (Neubauer chamber) and sperm morphology (phase contrast microscopy) were performed. The diluted semen was packaged in 0.25 mL straws, and cooling was performed on computerized machine (TK 4000®), using a cooling rate of -0.25°C/min to 5°C. Semen was kept in balance at 5°C for 4 h. The straws were frozen in an ice chest, kept at 5 cm from the surface of liquid nitrogen for 20 min and then immersed in liquid nitrogen. The samples were kept in cryogenic container until thawing. Post-thaw kinetic parameters during incubation at 37°C (CASA), sperm membrane integrity (SYBR-14/PI), membrane functionality (hypo-osmotic swelling test) and DNA fragmentation (%DFI - SCSA) were evaluated after thawing. Immediately post-thaw, total motility was higher in the control (56.53 ± 9.73) than in the tested extenders; however, after 30 min the difference was no longer detected.[…]

Low density lipoproteins at 2% concentration can replace whole egg yolk in tes-tris-milk extender for freezing buffalo sperm cells

Background: Over the years, the most commonly used extenders for semen cryopreservation contain egg yolk as cryoprotectant. However, more recent studies have used the low density lipoproteins, extract of hen egg yolk which is responsible for the cryoprotective effect. Nevertheless, little was known about its required minimum concentration as well as its interaction with other extra cellular cryoprotectants, like skimmed milk. The present study aimed at investigating the effect of replacing whole egg yolk by adding low density lipoproteins at low concentrations, in TES-Tris-skim milk based extender, on the post-thaw quality of buffalo bull sperm.Materials, Methods & Results: Eighteen ejaculates were collected from six buffalo bulls and diluted with TES-Tris-skim milk based extender containing LDL, extracted from hen egg yolks, at the concentrations of 2%, 4%, 8% and 14%, against a control extender containing 20% fresh egg yolk. After semen collection, analyses of subjective motility, vigor, force tourbillon, sperm concentration (Neubauer chamber) and sperm morphology (phase contrast microscopy) were performed. The diluted semen was packaged in 0.25 mL straws, and cooling was performed on computerized machine (TK 4000®), using a cooling rate of -0.25°C/min to 5°C. Semen was kept in balance at 5°C for 4 h. The straws were frozen in an ice chest, kept at 5 cm from the surface of liquid nitrogen for 20 min and then immersed in liquid nitrogen. The samples were kept in cryogenic container until thawing. Post-thaw kinetic parameters during incubation at 37°C (CASA), sperm membrane integrity (SYBR-14/PI), membrane functionality (hypo-osmotic swelling test) and DNA fragmentation (%DFI - SCSA) were evaluated after thawing. Immediately post-thaw, total motility was higher in the control (56.53 ± 9.73) than in the tested extenders; however, after 30 min the difference was no longer detected.[…](AU)

Peculiarities of the buffalo species for andrological evaluation – results of four years of study and weekly semen collection schedule

The aim of the present review is to provide complementary information about reproductive characteristics of male buffaloes having as perspective a four – year-study based on a weekly seminal collection schedule and collection of data in partner properties of several regions of Brazil. Aspects of testicular growth, reproductive behavior and characteristics of 1477 ejaculates of 13 donors are discussed in conjunction with data available in the literature.

Exame andrológico de bubalinos / Andrological examination of buffalos

A revisão tem como objetivo reavivar as particularidades da espécie bubalina visando a avaliaçãoandrológica. São abordadas as particularidades e anormalidades de desenvolvimento do sistema genital domacho, aspectos da puberdade e maturidade sexual, particularidades do comportamento reprodutivo,características do espermatozoide, liquido seminal e do ejaculado de búfalos.(AU)

The literature review focuses particularities of the buffalo specie and is directed to veterinarians aimingthe breeding soundness evaluation of bulls. Anatomical and abnormal developmental aspects of the genital tractare approached; puberty and sexual maturity, particularities of the reproductive behavior, characteristics of thesperm cells, seminal fluid and ejaculate are discussed.(AU)

Peculiarities of the buffalo species for andrological evaluation results of four years of study and weekly semen collection schedule

The aim of the present review is to provide complementary information about reproductive characteristics of male buffaloes having as perspective a four year-study based on a weekly seminal collection schedule and collection of data in partner properties of several regions of Brazil. Aspects of testicular growth, reproductive behavior and characteristics of 1477 ejaculates of 13 donors are discussed in conjunction with data available in the literature.(AU)

Exame andrológico de bubalinos / Andrological examination of buffalos

A revisão tem como objetivo reavivar as particularidades da espécie bubalina visando a avaliaçãoandrológica. São abordadas as particularidades e anormalidades de desenvolvimento do sistema genital domacho, aspectos da puberdade e maturidade sexual, particularidades do comportamento reprodutivo,características do espermatozoide, liquido seminal e do ejaculado de búfalos.

The literature review focuses particularities of the buffalo specie and is directed to veterinarians aimingthe breeding soundness evaluation of bulls. Anatomical and abnormal developmental aspects of the genital tractare approached; puberty and sexual maturity, particularities of the reproductive behavior, characteristics of thesperm cells, seminal fluid and ejaculate are discussed.