Veterinary Research Forum

Abstract This study evaluated the protective effects of intraperitoneal (IP) tannic acid (TA) against ischemia-reperfusion (IR) injury in a rat model of testicular torsion. Eighteen mature male Wistar rats were randomized into three groups, including sham (surgery without ischemia), IR (3 hr ischemia + 3 hr reperfusion), and IR + TA (50.00 mg kg^-1 TA; 100 µL intraperitoneally 30 min before reperfusion). Testicular tissues were sampled immediately after reperfusion for biochemical assays to measure malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels. Epididymides were analyzed 60 days later for sperm count, motility, viability, morphology, and DNA integrity. The IR significantly elevated MDA and sperm DNA damage while reducing SOD, GPx, sperm parameters, testicular weight, and spermatogenesis. The TA administration reversed these changes and restored the parameters to levels close to those of the sham group. Overall, intraperitoneal TA mitigated IR-induced oxidative stress and preserved reproductive function, indicating its potential therapeutic value in testicular torsion.

Abstract This study examined the effects of alpha-ketoglutaric acid (AKG; 2.00, 4.00, and 8.00 mM L^-1) and folic acid (FA; 50.00 nM L^-1) on bull sperm cells under ammonia stress induced by 175 µM L^-1 ammonium chloride. Sperm parameters including kinematic motility, survival rate, membrane integrity, DNA integrity, superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), total antioxidant capacity (TAC) activities, and apoptosis were assessed in the groups. Sperm motility indices, survival rate, plasma membrane integrity, SOD, CAT, TAC, and GPx enzymes activity, DNA damage, and apoptosis in the treated groups were significantly differed from those in the control groups. The AKG concentrations of 4.00 and 8.00 mM L^-1 co-supplemented with 50.00 nM L^-1 FA mitigated the negative effects of ammonia on sperm cells. This study indicated that supplementation with AKG and FA at the desired concentrations counteracted the adverse effects of ammonia toxicity that preceded clinical signs. Further studies are needed to evaluate the fertility of these sperms, either in vitro or in vivo.

Abstract During the freezing process of semen, due to the generating of significant amounts of free radicals, the quality of sperm changes. Epigallocatechin-3-gallate (EGCG) is a green tea catechin, which in this study was applied to investigate its effect on the quality of bulls' sperm. We collected semen samples with an artificial vagina from 12 Simmental bulls to evaluate the effect of EGCG (10.00 and 20.00 µmol) in two cryopreserving methods on the quality parameters of semen. We designed six groups including two control groups (method one and two) and four treatments (EGCG 10.00 µmol + method one; EGCG 20.00 µmol + method one; EGCG 10.00 µmol + method two; EGCG 20.00 µmol + method two). The 20.00 µmol EGCG and a method two significantly affected the amending oxidative conditions as well as an increase in total antioxidant capacity and a decrease in malondialdehyde. The effect of EGCG in both concentrations was more on method two. The desired impact on sperm motility, viability, inhibition of lipid peroxidation and sperm DNA damage was observed in EGCG groups compared to control groups. Among the two methods, the method two had fewer adverse effects on the plasma membrane, motility parameters, viability and DNA of sperm. The EGCG in the semen extender yielded a favorable impact on thawed sperm. This effect was prompted in combination with the method two.

Abstract Sperm survives for a very short time in fresh semen, and slow cooling to 5.00 ˚C kills a large number of sperms. This study was aimed to compare the semen quality parameters and anti-oxidant levels in four extenders (manual, Triladyl, Steridyl and AndroMed). Semen samples were obtained from a total number of 12 dual-purpose Simmental bulls kept in the Simmental Cattle Breeding Center for a period of 3 months using an artificial vagina. Sperm viability, motility, abnormal morphology, plasma membrane integrity, DNA damage, chromatin quality, total antioxidant capacity (TAC) and lipid peroxidation were evaluated. The highest progressive motility, viability, plasma membrane integrity, and TAC and the lowest levels of malondi-aldehyde in the frozen-thawed semen belonged to the semen group frozen with Triladyl. Parameters of motility were higher in the frozen-thawed semen with Triladyl than in other groups, indicating a significant difference from the manual extender. Among the extenders studied, Triladyl was the most suitable for semen freezing in Simmental bulls.

Abstract The reduction of spermatozoa survival time is a major problem of canine chilled sperm for artificial insemination. The current study looks at the possible advantages of chilling canine sperm to 4.00 ˚C for three days using Tribulus terrestris aqueous extract (TTAE). Three mixed-breed dogs were utilized to extract 24 ejaculates, which were then diluted in a Tris-based extender. The ejaculates were then divided into five groups including 20.00, 40.00 and 50.00 µg mL^-1 of TTAE, sham (distilled water devoid of TTAE) and control (without TTAE) groups. During the three days of experiment, several parameters were measured every 24 hr. It was noticed that after 48 and 72 hr of liquid storage, total and progressive motilities were greater in the group with the 40.00 µg mL^-1 TTAE concentration than the control group. Compared to the control group, the group with the 40.00 µg mL^-1 TTAE concentration exhibited superior motility and viability. The percentages obtained from the hypo-osmotic swelling test were much greater. In contrast to the control group, DNA integrity was poorer in the 40.00 µg mL^-1 TTAE concentration. After 72 hr of storage, the group with 40.00 µg mL^-1 TTAE concentration had lower malondialdehyde levels but considerably greater total anti-oxidant capacity, superoxide dismutase, glutathione peroxidase and catalase levels than the control groups. The current study found that supplementing the semen extender with 40.00 µg mL^-1 TTAE improves semen parameters after 72 hr of storage at 4.00 ˚C, and therefore can improve fertilization efficiency.

Abstract Heat stress (HS) has caused relative hypoxia, oxidative stress and high level of homocysteine, which contributes significantly to fertility failures in bulls. The aim of present study was to evaluate the role of dietary betaine (BET) in improving dual purpose Simmental (Fleckvieh) post-thawed semen quality especially during the hottest summer days. A total number of 16 mature bulls were randomly assigned to three equal groups including: 1) Control condition (without betaine), 2) BET1: 57.00 mg of betaine kg^-1 per day and 3) BET2: 114 mg of betaine kg^-1 per day, through daily intakes for 90 days in summer. Plasma levels of homocysteine, seminal plasma antioxidants levels and sperm parameters such as DNA fragmentation, chromatin integrity, motility, viability, morphology and membrane integrity were evaluated. Under maximal HS, serum homocysteine concentrations were reached 16.67 ± 0.09 µmol L^-1. Dietary betaine supplementation influenced DNA fragmentation of sperm and was higher in the control group compared to BET2 group. There were significant decreases in seminal plasma superoxide dismutase (SOD), glutathione peroxidase (GPx) activity and sperm viability and motility in bulls treated with betaine. The activity of GPx and SOD in the control group was increased up to 0.08 ± 0.00 U mg^-1 protein and 0.52 ± 0.01 U mg^-1 protein in seminal plasma. There were no significant differences between groups in the percentage of swollen spermatozoa, membrane integrity, sperm morphology, abnormal head morphology and percentage of spermatozoa stained with aniline blue. In conclusion, BET supplements improved semen parameters in sperm motility, sperm viability and influenced DNA fragmentation during HS with reduction in serum homocysteine concentrations.

Abstract Fertility is one of the most important parameters in breeder farms and cockerels play an outstanding role in fertility of eggs in broiler breeder units. Todays, supplementation of feed-additives such as organic selenium is used to increase fertility. The aim of this study was to evaluate the effects of different levels of Nano-Selenium (Nano-Se) on expression of molecular markers of spermatogonial stem cells (SSCs) in testis of broiler breeder males. A total of 30 roosters of 40 weeks age were randomly divided into 5 groups. Groups were as follow: 1) control (normal diet), 2) diet supplemented with 0.3 mg/kg sodium Selenite, 3) diet supplemented with 0.15 mg/kg Nano-Se, 4) diet supplemented with 0.3 mg/kg Nano-Se and 5) diet supplemented with 0.6 mg/kg Nano-Se. At the end of experimental period, birds autopsied and samples from testis of all birds were taken. The samples were used to examine the β1-integrin (CD29), thy-1(CD90 and NANOG mRNA expression by quantitative Real-Time PCR. The results of this study showed that testis of the groups fed with diets supplemented with 0.6mg/kg and 0.15mg/kg of Nano-Se had the highest and lowest mRNA expression of SSCs markers, respectively. In conclusion, the present study indicated that Nano-Se had advantages to sodium Selenite and 0.6 mg/kg of Nano-Se supplemented in males' diet in broiler breeders farms may contributes to optimal fertility via increasing mRNA expression of SSCs markers of roosters' testis and could be used to delay reduction of fertility caused by aging in broiler breeder males.

Abstract Reactive oxygen species (ROS) generation, induced by the cryopreservation process, can be responsible for mammalian sperm damage. Curcumin is known as an effective antioxidant against oxidative stress. The aim of this study was to evaluate the effects of curcumin on sperm count, motility and viability, semen total antioxidant capacity and DNA integrity of rat spermatozoa during semen freeze-thawing process. Sperm collected from 10 adult rats were divided into two groups (n=10 for each group): control and a test group supplemented with 2.5 mM curcumin. After freezing-thawing, the number of spermatozoa, motility, viability, total antioxidant capacity (TAC), and DNA integrity of the sperm were analyzed. Motility, viability and DNA integrity of sperm were significantly preserved in treatment groups compared to the control (p < 0.05) after freezing-thawing. Following cryopreservation, TAC was significantly preserved in thawing semen supplemented with curcumin compared to the control group (p<0.05). Based on our results, it is concluded that curcumin addition during freezing resulted in positive effects on sperm parameters after thawing in adult rats.