BACKGROUND: Bovine viral diarrhea virus (BVDV) is one of the most important pathogens. OBJECTIVES: The aim of this study was to investigate the effects of cytopathic (CP) and non-cytopathic (NCP) biotypes of BVDV on vital status, membrane integrity, and motility of sperm cells in Holstein dairy bulls in vitro. METHODS: BVDV-free frozen semen samples were counted after thawing and centrifuged to separate live sperms. A sample containing 105 spermatozoa/mL was prepared. CP and NCP BVDV with 3 different doses of 105 (high dose), 104 (medium dose), and 103 (low dose) tissue culture infectious dose (TCID) 50/mL were challenged to sperm cells. After 2 hours of incubation at 38.5°C, eosin-nigrosine staining and hypoosmotic swelling (HOS) test were performed to assess the sperm viability and plasma membrane integrity. Computer assisted semen analysis (CASA) was used to evaluate the sperm motility parameters. The obtained data were analyzed using GLM method in SAS software. RESULTS: The percentage of live spermatozoa in the control group was 72±3.60%. However, it decreased significantly with the increase of virus concentration in both groups (p ≤0.05). Sperm integrity in the control group showed that the quality of semen was 65± 3.21. But the effect of virus biotypes resulted in a significant decrease in both high (105) and low (103) concentrations (p ≤0.05). BVDV biotypes are able to reduce different sperm movements as their concentration-increases. CONCLUSIONS: We concluded that CP and NCP biotypes of BVDV had a significant effect (p ≤0.05) on survival, plasma membrane integrity, and motility of sperm cells in vitro.

BACKGROUND: Bovine viral diarrhea virus (BVDV) is one of the most important pathogens. OBJECTIVES: The aim of this study was to investigate the effects of cytopathic (CP) and non-cytopathic (NCP) biotypes of BVDV on vital status, membrane integrity, and motility of sperm cells in Holstein dairy bulls in vitro. METHODS: BVDV-free frozen semen samples were counted after thawing and centrifuged to separate live sperms. A sample containing 105 spermatozoa/mL was prepared. CP and NCP BVDV with 3 different doses of 105 (high dose), 104 (medium dose), and 103 (low dose) tissue culture infectious dose (TCID) 50/mL were challenged to sperm cells. After 2 hours of incubation at 38.5°C, eosin-nigrosine staining and hypoosmotic swelling (HOS) test were performed to assess the sperm viability and plasma membrane integrity. Computer assisted semen analysis (CASA) was used to evaluate the sperm motility parameters. The obtained data were analyzed using GLM method in SAS software. RESULTS: The percentage of live spermatozoa in the control group was 72±3.60%. However, it decreased significantly with the increase of virus concentration in both groups (p ≤0.05). Sperm integrity in the control group showed that the quality of semen was 65± 3.21. But the effect of virus biotypes resulted in a significant decrease in both high (105) and low (103) concentrations (p ≤0.05). BVDV biotypes are able to reduce different sperm movements as their concentration-increases. CONCLUSIONS: We concluded that CP and NCP biotypes of BVDV had a significant effect (p ≤0.05) on survival, plasma membrane integrity, and motility of sperm cells in vitro.

Background: Newborn gender ratio is one of the most important factors in livestock industry. This ratio has affected on economic condition and controls sex-linked genetically transferred diseases. Offspring sex ratio is affected by such various factors. One of these factors is the Y to X bearing sperm ratio in normal semen that is called primary sex ratio, season and individual differences are important factors that can have an effect on primary sex ratio. OBJECTIVES: The objective of this study was to investigate two main effective factors, Individual difference and season, on proportion of sperms containing Y-chromosomes to sperms containing X-chromosomes in bull semen. METHODS: Semens were collected from 16 bulls during summer (Jul-Aug) and winter (Dec. to Jun). After sperm analysis, DNAs were extracted and Real-time PCR performed using three sets of primers to study SRY (Y-chromosome specific sequence), PLP (X-chromosome specific sequence) and PAR (Housekeeping) genes. RESULTS: The results showed that the sex ratio of sperms in normal ejaculation was not equal in different bulls.  Moreover, season can affect primary sex ratio. Y-bearing sperm increase in summer. CONCLUSIONS: We concluded that the primary sex ratio is affected by individual differences and season. We also suggested using Northern blotting on PCR products to confirm results.

Background: Newborn gender ratio is one of the most important factors in livestock industry. This ratio has affected on economic condition and controls sex-linked genetically transferred diseases. Offspring sex ratio is affected by such various factors. One of these factors is the Y to X bearing sperm ratio in normal semen that is called primary sex ratio, season and individual differences are important factors that can have an effect on primary sex ratio. OBJECTIVES: The objective of this study was to investigate two main effective factors, Individual difference and season, on proportion of sperms containing Y-chromosomes to sperms containing X-chromosomes in bull semen. METHODS: Semens were collected from 16 bulls during summer (Jul-Aug) and winter (Dec. to Jun). After sperm analysis, DNAs were extracted and Real-time PCR performed using three sets of primers to study SRY (Y-chromosome specific sequence), PLP (X-chromosome specific sequence) and PAR (Housekeeping) genes. RESULTS: The results showed that the sex ratio of sperms in normal ejaculation was not equal in different bulls.  Moreover, season can affect primary sex ratio. Y-bearing sperm increase in summer. CONCLUSIONS: We concluded that the primary sex ratio is affected by individual differences and season. We also suggested using Northern blotting on PCR products to confirm results.

BACKGROUND: Semen cryopreservation might be influenced by sperm concentration. OBJECTIVES: This study was conducted to investigate three different semen concentrations [100 (C100), 50 (C50), and 25 (C25) × 106 spermatozoa/mL] on freezability of bull semen. METHODS: On each collection day, four ejaculates were collected (a total of 24 ejaculates from four bulls), pooled and divided to three equal parts. Each part was diluted to reach to one of the above mentioned final semen concentration and then frozen. After thawing, sperm motility, apoptosis status and mitochondrial activity were assessed. RESULTS: The results showed that C100 resulted in significantly higher total sperm motility compared to C50 and C25 groups. The percentage of live spermatozoa was significantly higher in C100 compared to C50 and C25 groups. Also, C25 resulted in significantly higher early and late apoptotic spermatozoa compared to C50 and C100 groups. The mitochondrial activity was significantly lower in C25 compared to C100 and C50 groups. CONCLUSIONS: It seems that low sperm concentrations (as low as 50×106) may be less advantageous for cryopreservation.

BACKGROUND: Semen cryopreservation might be influenced by sperm concentration. OBJECTIVES: This study was conducted to investigate three different semen concentrations [100 (C100), 50 (C50), and 25 (C25) × 106 spermatozoa/mL] on freezability of bull semen. METHODS: On each collection day, four ejaculates were collected (a total of 24 ejaculates from four bulls), pooled and divided to three equal parts. Each part was diluted to reach to one of the above mentioned final semen concentration and then frozen. After thawing, sperm motility, apoptosis status and mitochondrial activity were assessed. RESULTS: The results showed that C100 resulted in significantly higher total sperm motility compared to C50 and C25 groups. The percentage of live spermatozoa was significantly higher in C100 compared to C50 and C25 groups. Also, C25 resulted in significantly higher early and late apoptotic spermatozoa compared to C50 and C100 groups. The mitochondrial activity was significantly lower in C25 compared to C100 and C50 groups. CONCLUSIONS: It seems that low sperm concentrations (as low as 50×106) may be less advantageous for cryopreservation.