Microbial composition of goat buck's ejaculates is modified by the process of preparing and storing refrigerated semen doses.

Ejaculates present their own microbiota, and a link between ejaculates' microbiota and sperm quality and fertility exists. With the development of artificial insemination in animal breeding, ejaculates must be manipulated by diluting them with extenders and storing them at temperatures below body temperature. The effects that these processes have on the original semen microbiota have never been studied.

The Importance of Studying Factors That Affect the In Vitro Evaluation of Semen Quality to Predict Potential Fertility in Males.

The presence of sub-fertile or infertile males in farms or artificial insemination (AI) centres has a great impact on the reproductive and economic performance of the livestock industry [...

Microbiota in Goat Buck Ejaculates Differs Between Breeding and Non-breeding Seasons.

Changes in semen microbiota are associated with alterations to sperm quality and fertility. However, the microbiota from most livestock species has not yet been studied. Goats are seasonal breeders, but semen microbiota has never been described in this species, and it is unknown how seasonality affects it.

Fertility prediction in dairy goats from Murciano-Granadina breed: The role of sperm evaluation and female traits.

Fertility is one of the most economically important traits in farm animals, due to the direct and indirect costs associated to low pregnancy rates. Thus, one of the priority goals in animal reproduction is to predict the performance that the semen doses will have in vivo based on the quality values obtained in laboratory assays. Attempts have been made for getting a predictive model of fertility of frozen-thawed sperm in dairy goats, but similar studies have not been conducted for chilled goat buck sperm doses that are mostly used for artificial insemination in many countries including Spain.

Effect of the Refrigeration System on In Vitro Quality and In Vivo Fertility of Goat Buck Sperm.

Cooling goat sperm insemination doses to 4 °C causes a delay in their delivery. However, chilling these doses during the transportation period could expedite their delivery and the insemination process. In this study, an economical and simple apparatus for chilling goat semen doses in itinere was developed, and the in vitro quality and in vivo fertility of these doses were compared with those chilled by means of a programmable water bath in the laboratory at a rate of -0.

Insemination extender supplementation with bestatin and EDTA has no effect on rabbit reproductive performance.

The addition of aminopeptidase inhibitors (AMIs) to rabbit semen extenders could be a solution to decrease the hormone degradation (GnRH) by the aminopeptidases existing in the seminal plasma. Therefore, the quantity of GnRH needed to induce ovulation in doe would be comparable with the amount administered intramuscularly (i.m.

Freezability genetics in rabbit semen.

The aim of this study was to estimate the heritability of semen freezability and to estimate the genetic correlation between frozen-thawed sperm traits and the growth rate in a paternal rabbit line. Estimated heritabilities showed that frozen-thawed semen traits are heritable (ranged between 0.08 and 0.

Effect of different freezing velocities on the quality and fertilising ability of cryopreserved rabbit spermatozoa.

The freezing step of the cryopreservation protocol negatively influences the quality and fertilising ability of rabbit spermatozoa. This study determines the effect of different rates of freezing on the quality and fertilising ability of rabbit spermatozoa cryopreserved with dimethylsulfoxide (DMSO) (1.75M) and sucrose (0.

Reducing the time rabbit sperm are held at 5 °C negatively affects their fertilizing ability after cryopreservation.

Cooling sperm to and equilibrating the sperm at 5 °C require the most time in any sperm cryopreservation protocol. Reducing the time required for these phases would simplify sperm freezing protocols and allow greater number of ejaculates to be processed and frozen in a given time. This study determined how holding rabbit sperm at 5 °C for different lengths of time (0, 10, 15, 20, 30, or 45 minutes) affected the quality of rabbit sperm, measured by in vitro assays, and if reducing the cooling time to only 10 minutes affected the fertilizing ability of the sperm.

Development of methods for cryopreservation of rooster sperm from the endangered breed "Gallina Valenciana de Chulilla" using low glycerol concentrations.

Glycerol (11%; v:v) is the cryoprotectant most often used for the cryopreservation of rooster sperm. However, chicken breeds differ in the resistance of their sperm to the cryopreservation process and endangered or local breeds usually present low fertilizing ability when conventional sperm cryopreservation protocols are used. The objective of this study was to optimize the protocol for the cryopreservation of the sperm from the endangered breed "Gallina Valenciana de Chulilla".

Aminopeptidase activity in seminal plasma and effect of dilution rate on rabbit reproductive performance after insemination with an extender supplemented with buserelin acetate.

Ovulation induction in artificially inseminated rabbits by adding GnRH synthetic analogues in the seminal doses is a welfare-orientated method to induce ovulation in rabbits and could have some advantages in field practice. This study was conducted to determine the effect of male genotype on the aminopeptidase activity in rabbit seminal plasma and the effects of dilution rate of semen on availability and reproductive performance when buserelin acetate is added to the seminal dose. To study the aminopeptidase activity, 12 mature bucks belonging to a paternal line and 12 from a maternal line were used.

Addition of cholesterol-loaded cyclodextrins to the thawing extender: effects on boar sperm quality.

The aim of the present study was to evaluate the effect that the addition of cholesterol-loaded cyclodextrins (CLC) to the thawing extender has on the quality of frozen-thawed boar sperm. Pooled semen (n = 5) from three boars was used for the experiments. The semen was cryopreserved with an egg-yolk-based extender, it was diluted after thawing in Beltsville thawing solution (BTS) supplemented with different concentrations of CLC (0, 12.

Effect of cholesterol-loaded cyclodextrins on bull and goat sperm processed with fast or slow cryopreservation protocols.

Cholesterol-loaded cyclodextrins (CLC) added to the sperm before cryopreservation enhance sperm quality after freeze-thawing in several cold shock-sensitive species, including cattle and goats. However, all studies conducted to date have used conventional protocols, in which sperm are cooled slowly to 5°C before freezing. As cholesterol plays a significant role in sperm cold shock resistance, it is possible that CLC-treated sperm can withstand cooling damage when the sperm are not cooled slowly to 5°C before freezing.

Egg yolk and glycerol requirements for freezing boar spermatozoa treated with methyl β-cyclodextrin or cholesterol-loaded cyclodextrin.

Egg yolk (EY) and glycerol are common constituents of extenders used for sperm cryopreservation. It has been demonstrated that using cholesterol-loaded cyclodextrins (CLC) improves sperm cryosurvival in several species. However, standard freezing extenders might not be the most appropriate for CLC-treated sperm.

Optimizing conditions for treating goat semen with cholesterol-loaded cyclodextrins prior to freezing to improve cryosurvival.

The fertility of goat sperm is highly variable and new methods for improving sperm cryosurvival are needed. Cholesterol plays important roles in membrane fluidity, cold shock sensitivity and cryodamage, and treating sperm from cold-shock sensitive species with cholesterol-loaded cyclodextrins (CLC) prior to cryopreservation enhances sperm cryosurvival. The aim of this study was to develop a CLC-treatment to optimize goat sperm cryopreservation.

In vivo fertilising ability of frozen-thawed boar sperm treated with cholesterol-loaded cyclodextrins prior to cryopreservation.

The use of frozen-thawed (FT) sperm for the artificial insemination of pigs is rare. Treating boar sperm with cholesterol-loaded cyclodextrins (CLC) prior to cryopreservation enhances the penetration of immature oocytes in vitro, and this phenomenon has been positively correlated with in vivo fertilisation ability in pigs. The objective of this study was to compare the in vivo fertilising ability of boar sperm treated with 0 (control) or 1mg CLC/120×10(6) sperm (CLC) prior to freezing.

Treatment with cholesterol-loaded methyl-β-cyclodextrin increased the cholesterol in rabbit oocytes, but did not improve developmental competence of cryopreserved oocytes.

Membrane cholesterol:phospholipids ratio is an important determinant of cell chilling sensitivity. At low temperatures, major membrane destabilisation occurs when the membrane undergoes a phase transition. To increase membrane fluidity and stability during cooling and thus increase oocyte cryoresistance, cholesterol has been added to the plasma membrane.

Environmental and male variation factors of freezability in rabbit semen.

The aim of this study was to analyze the environmental and male effects that could have an influence on sperm freezability using a recursive model. A total of 853 ejaculates from 217 males belonged to a paternal rabbit line were collected and frozen. Six different traits were evaluated: the sperm concentration (10(6) spermatozoa per mL), the acrosome integrity on fresh (%) and frozen-thawed semen (%), the sperm motility on fresh (%) and frozen-thawed semen (%), and the percentage of viable sperm on frozen-thawed semen (%).

Effect of a pre-freezing treatment with cholesterol-loaded cyclodextrins on boar sperm longevity, capacitation dynamics, ability to adhere to porcine oviductal epithelial cells in vitro and DNA fragmentation dynamics.

The aim of this work was to examine how a pre-freezing treatment with cholesterol-loaded cyclodextrins (CLC) affects boar sperm longevity, capacitation dynamics, ability to bind to a porcine telomerase-immortalised oviductal epithelial cell line (TERT-OPEC) in vitro and DNA integrity dynamics after freeze-thawing. Although the samples treated with CLC exhibited lower sperm quality than the control samples (P<0.05) immediately after thawing, these differences disappeared (P>0.

Effect of different monosaccharides and disaccharides on boar sperm quality after cryopreservation.

The aim of the present study was to evaluate the cryoprotectant effect of different non-permeating sugars for boar sperm. Pooled semen from three boars was used for the experiments. In the first experiment, the sperm quality of boar sperm cryopreserved with an egg-yolk based extender supplemented with different monosaccharides (glucose, galactose or fructose) was compared to a control cryopreserved in lactose-egg yolk extender.

Is sperm freezability related to the post-thaw lipid peroxidation and the formation of reactive oxygen species in boars?

The aim of the present study was to determine whether the levels of reactive oxygen species (ROS) substances production and the levels of lipid peroxidation of the sperm membrane were related to the quality that the ejaculates exhibited after cryopreservation in boars. Ejaculates from 42 healthy boars were used in this study and they were cryopreserved with the lactose-egg yolk extender (LEY). Several sperm quality parameters were assessed by flow cytometry in samples incubated for 30 and 150 min at 37 °C after thawing: the percentage of sperm with intact plasma membrane (SIPM), intracellular reactive oxygen substances production through mean of DCF fluorescence intensity of total sperm (mean-DCF) and the percentage of viable and non-viable sperm containing oxidized BODIPY (VSOB and NVSOB).

Response of boar sperm to the treatment with cholesterol-loaded cyclodextrins added prior to cryopreservation.

Cryopreserved boar sperm is not used extensively for artificial insemination, owing to the poor fertility rates of the sperm after freezing and thawing. The sperm membrane is damaged as the cells are cooled from body temperature to 5°C (cold shock), as well as during the freeze-thaw process. Increasing the cholesterol content of boar sperm membranes could help them survive cryopreservation, similar to sperm from other species that are cold shock sensitive.

Treating boar sperm with cholesterol-loaded cyclodextrins widens the sperm osmotic tolerance limits and enhances the in vitro sperm fertilising ability.

Treating sperm with cholesterol-loaded cyclodextrins (CLC) improves the cryosurvival of the sperm of different cold-shock sensitive species. However, the response of boar sperm to this treatment is not fully understood. The aim of this study was to determine how CLC and methyl-β-cyclodextrin (MβCD, not loaded with cholesterol) affect the parameters for boar sperm functionality, including sperm osmotic resistance, and the ability of the sperm to capacitate and to penetrate the sow's immature oocytes in vitro.

Cryoprotectant and freezing-process alter the ability of chicken sperm to acrosome react.

Sperm surviving after freezing-thawing is usually 40-50% of the initial population. Damage during this process affects both fertilizing ability and its duration in avian species. However, the effect of cryopreservation on the sperm ability to undergo the acrosome reaction, the initial event of fertilization, is still in question in birds.

Use of cholesterol in sperm cryopreservation: present moment and perspectives to future.

Sperm cryosurvival rates are not optimal for most species. Therefore, new cryopreservation strategies are needed with the objective of increasing the number of surviving sperm and the quality of those sperm after thawing. Cholesterol plays important roles in many sperm functions, including effects on membrane properties.