Protective effects of different doses of MitoQ separately and combined with trehalose on oxidative stress and sperm function of cryopreserved Markhoz goat semen.

The mitochondria-targeted antioxidant MitoQ has been regarded as an effective antioxidant agent against cryo-induced oxidative cellular damage. This study aimed to evaluate the use of different doses of MitoQ combined with trehalose to minimize mitochondrial impairment and oxidative stress during sperm cryopreservation of Markhoz goat. For this, semen samples (n = 50) were collected by electroejaculation every 5 days from 5 bucks in 10 replicates. On each collection day, 5 ejaculates (one ejaculate for each buck) were pooled and then diluted in eight different Tris-based extenders as follows: no additives (control), 20, 200, 2000 nM of MitoQ (MT20, MT200, MT 2000, respectively), 150 mM of trehalose (Tr), MT20+Tr, MT200+Tr, MT2000+Tr. The semen samples were frozen using a standard protocol, and sperm function and oxidative stress were evaluated after thawing. The semen extender supplemented with MT200+Tr had higher (P < 0.05) total and progressive motility, acrosome and membrane integrity, superoxide dismutase, glutathione peroxidase, total antioxidant capacity, and lower (P < 0.05) DNA fragmentation, malondialdehyde and intracellular hydrogen peroxide levels than the all other groups except MT200; meanwhile, MT200 was also improved (P < 0.05) in these parameters than in the control group. Furthermore, MT200 and MT200+Tr showed higher (P < 0.05) percentages of live cryopreserved sperm with high mitochondrial activity than other groups. However, abnormality percentage and catalase activity of frozen-thawed sperm were not affected by treatments (P > 0.05). To conclude, we have found that supplementation of 200 nM MitoQ alone or in combination with 150 mM trehalose to semen extender improved the quality of cryopreserved sperm in goats, which is associated with enhanced antioxidant enzymatic defense and mitochondrial activity and reduced DNA fragmentation.

Letrozole, an aromatase inhibitor, improves seminal parameters and hormonal profile in aged endangered Markhoz bucks.

OBJECTIVE: Letrozole, a potent aromatase inhibitor, is known to have the potential to modify male reproductive function by altering sex hormone levels. This study aimed to evaluate the semen and testicular characteristics and hormonal profile of aged Mrakhoz bucks (Capra hircus) treated with letrozole. METHODS: Twelve Markhoz male goats, aged between 4.5 to 5.5 years with an average body weight (BW) of 61.05±4.97 kg were used for the study. Animals were randomly divided into two equal groups and subcutaneously received either 0.25 mg/kg BW of letrozole or a control every week for 2 months. The semen collections were performed every 10 days, and blood samples and testicular biometric records were collected at 20 days intervals. RESULTS: Letrozole causes increased testosterone and follicle-stimulating hormone levels, testosterone to estradiol ratio, semen index and reaction time during the period from 20th to 60th days (p<0.05). Furthermore, letrozole-treated bucks had higher semen volume, sperm concentration, and total sperm per ejaculate from 30th to 60th days (p<0.05). However, no differences occurred between the groups in scrotal circumference, relative testicular volume, semen pH, abnormality, acrosome integrity, and membrane integrity of sperm during the study (p>0.05). The serum luteinizing hormone levels, sperm viability, motility, and progressive motility increased, and estradiol levels decreased after 40th to 60th days of letrozole treatment (p<0.05). CONCLUSION: Letrozole application to aged Markhoz bucks provokes reproductive hormonal axis which, in turn, induces enhancement of semen production and quality.

Effects of letrozole administration on growth and reproductive performance in Markhoz goat bucklings.

This study evaluated the growth performance, testicular and semen characteristics, and hormonal profile of Markhoz (Iranian Angora) bucklings injected with letrozole (LTZ). Twenty-eight 4-4.5 month old bucks were randomly assigned into four groups and received either 0.25 mg/kg body weight (BW) LTZ subcutaneously (sc LTZ) or intramuscularly (im LTZ), and also sc (sc CONT) or im (im CONT) controls every week for 3 months. The study was performed at the beginning of the breeding season in Sanandaj Animal Husbandry Research Station (46.99 °E, 35.31 °N). The results showed that LTZ causes increased final body weight (25.78 ± 1.61 kg), higher average daily gain (104 ± 0.03 g/days), and decreased feed conversion ratio (7.81 ± 2.57) (P < 0.05). The pre-slaughter, hot, and cold carcass weights (27.56 ± 2.40, 11.45 ± 1.07 and 11.11 ± 1.05 kg, respectively) were (P < 0.05) heavier in LTZ groups while other carcass characteristics did not differ between groups. No differences occurred between the groups in biochemical parameters, except high-density lipoprotein levels (35.47 ± 2.43 mg/dL) which was higher in LTZ treatments (P < 0.05). LTZ-treated bucks had larger scrotal circumference (20.12 ± 5.75 cm), higher relative testicular weight (560.91 ± 78.59 mg/100 g BW) and volume (175.5 ± 29.71 cm3), greater diameter of seminiferous tubules (224.5 ± 5.21 µm), and number of Sertoli cells (8.39 ± 0.77) (P < 0.05). Semen volume (0.74 ± 0.16 mL), sperm concentration (2.64 ± 0.19 × 10-9/mL), total sperm per ejaculate (1.95 ± 0.49 × 10-9), and semen index (1248 ± 323) increased (P < 0.05) by LTZ treatments, while semen pH (6.77), motility (80.91%), progressive motility (76.75%), viability (83.35%), abnormality (13.70%), acrosome integrity (78.06%), and membrane integrity (80.05%) of sperm remained unaffected. Intratesticular and serum testosterone (T) levels (7.97 ± 0.89 ng/mg protein and 2.47 ± 0.59 ng/mL, respectively), serum luteinizing hormone (LH), growth hormone (GH) levels (1.71 ± 0.24 and 3.62 ± 0.33 ng/mL, respectively) of LTZ groups were elevated, whereas intratesticular and serum estradiol (E2) levels (84.14 ± 8.15 pg/mg protein and 32.33 ± 2.16 pg/mL, respectively) decreased (P < 0.05). No differences were recorded between the sc and im routes of LTZ administration in the measured parameters. To conclude, we have found that LTZ treatment improves growth and reproductive functions of goat bucklings associated with increased serum LH and GH, elevated T and reduced E2 levels in both serum and testis.

Effects of Silver Nanoparticles on Hematological Parameters and Hepatorenal Functions in Laying Japanese Quails.

Silver nanoparticles (AgNPs) have recently emerged as a powerful agents for disinfection in the poultry industry. AgNPs are capable of epithelial barriers passing from the route of exposure to the vital organs and cells. This study evaluated the effects of AgNPs on organs weights, blood biochemical, hematological, and coagulation parameters, antioxidant enzyme activities, and histopathological changes and silver concentrations of liver and kidney tissues in laying Japanese quails after exposure to the nanoparticles. The layer quails were randomly assigned to 4 groups, consisting of six replicates, three quails each. The treatments included 0, 4, 8, and 12 mg/L of AgNPs in daily drinking water for 30 weeks. AgNPs decreased the relative weight of liver, ileum and large intestine (P < 0.05). Administration of AgNPs elevated plasma fibrinogen while decreased serum aspartate aminotransferase activity (P < 0.05). The antioxidant status of the liver showed that malondialdehyde level, an end product of lipid peroxidation, was higher (P < 0.05) and catalase activity was lower (P < 0.05) in the quails exposed to AgNPs. The accumulation of silver in the liver and kidney tissues were increased in a dose-dependent manner after exposure to AgNPs (P < 0.05). Histopathological findings showed reduced lipid vacuolization of hepatocytes in the 12 mg/L AgNPs treatment. In conclusion, the results indicated that AgNPs administration to drinking water can lead to oxidative stress and liver damage in laying quails which may be a predisposing for liver dysfunction.