Reza Asadpour

Seasonal variation in antioxidant enzyme activity in seminal plasma in Holstein bulls

Seminal oxidative stress status is emerging as a significant prognostic tool in assisted reproductive technology. A dynamic interplay between pro- and anti-antioxidant substances in the ejaculate is essential. In this study, we determined seasonal changes in the activity of the antioxidant enzyme defence system comprising catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) in seminal plasma (SP) of mature Holstein bull’s semen. Samples were collected by a bovine artificial vagina from 30 sexually mature Holstein bulls, and CAT, GPx and SOD activities were determined for different seasons. The CAT enzymatic activity determined in SP was greater in autumn as compared with other seasons (P < 0.01). Significantly lower GPx activity was found in winter compared with other seasons (62 ± 12 versus 133 ± 35; P < 0.01). However, SOD was not significantly affected by the season. The results reported confirm the influence of season on sperm quality. Furthermore, this study presents convincing evidence that SP composition is important in determining the antioxidant defence system of ejaculated spermatozoa.

Effects of Haematococcus pluvialis in maternal diet on reproductive performance and egg quality in rainbow trout (Oncorhynchus mykiss).

The aim of this study was to clarify the effects of dietary Haematococcus pluvialis (H.p) on reproductive performance in female rainbow trout and egg quality in terms of antioxidant system and biochemical parameters. 60 rainbow trout (2475.5 ± 64.4 g) were randomly assigned to 2 groups in triplicates and fed diet containing 3 g H.p kg(-1) feed equivalent to 30 mg astaxanthin kg(-1) die or control diet for 30 days. On days 20 and 30 during feeding trial, mature fish were weighed and sampled for stripping. Results indicated that supplementation of H.p did not improve total egg weight, egg number per gram and fecundity. There were few changes in triglyceride and total protein content in fish eggs. Level of glucose decreased markedly on day 30 while on day 20 of feeding trial, a non-significant decrease was shown in treatment group. On day 20, the level of malondialdehyde (MDA) indicating lipid peroxidation product significantly decreased in eggs of the treatment group. The activities of enzymes of the antioxidant system did not change during this study, even though slight increase in glutathione peroxidase in treatment group was revealed during this study. In conclusion, this study showed that female rainbow trout appear to benefit from inclusion of H.p in diet during their reproductive stages in terms of improved egg quality.

Detection of bovine leukosis provirus in blood and semen samples of bulls

Enzootic bovine leukosis is a chronic lymphoproliferative disorder in cattle caused by the exogenous retrovirus, bovine leukemia virus (BLV). There are numerous molecular protocols for the detection of bovine leukosis provirus in blood and semen. The aim of this study was to investigate the serology status of BLV infection in bulls in Tabriz, Iran and polymerase chain reaction (PCR) detection of viral genome of BLV in seminal cellular fraction and blood samples in sero-positive and sero-negative bulls. In this study, 45 serum samples from bulls from 18 different herds referred to the Artificial Insemination Centre were used to evaluate the serology infection of BLV by enzyme-linked immunosorbent assay. In addition, blood and semen samples of related bulls were used for the detection of BLV DNA. Antibodies against BLV were detected in five of 45 blood samples (4.4%), and PCR demonstrated that semen and blood samples of five sero-positive and one sero-negative bull were infected by BLV. Our findings support the power of a PCR test for BLV detection in bovine semen and blood samples and could be easily used for routine diagnosis. This data strongly suggest that semen from sero-positive bulls could result positive by PCR.