ABSTRACT
Background: The study was conducted to assess the effects of the digestible dietary energy level on some reproductive characteristics in African giant rat.Methods: Sixteen young males were randomly distributed into 4 groups of 4 animals each. To each group was attributed randomly one of the 4 dietary energy levels (3600 Kcal/kg, 3800 Kcal/kg, 4000 Kcal/kg or 4200 Kcal/kg). The daily distribution of experimental diets last six months, ie ended when cricetoma were 8 months old. At the end of that period, all animals were sacrificed.Results: Results showed an increase in testes weight with the augmentation of dietary digestible energy level (0.79±0.13, 0.88±0.17, 1.02±0.28 and 1.02±0.16 respectively for 3600 Kcal/kg, 3800 Kcal/kg, 4000 Kcal/kg and 4200 Kcal/kg). The serum testosterone level, the sperm mobility (76.67, 62, 63 and 57%) and count per cauda epididymis (18.25±3.75, 16.38±4.19, 10.83±2.02 and 10.13±2.9) and per gram cauda epididymis (39.09±11.82, 27.01±4.23, 15.41±3.31 and 17.40±7.28) significantly (p<0.05) decreased with the increasing level of digestible energy in the feed.Conclusions: The dietary digestible energy level that gave the higher reproductive performances in male African giant rat was 3600 Kcal/kg DM.
ABSTRACT
The present experiment was undertaken to study the relationship between clusterin (CLU) gene expression and in vitro sperm characteristics in buck semen. Fresh semen samples were collected from 12 bucks maintained in the organized goat farms by artificial vagina. Normalization of initial concentration of spermatozoa was carried out in all buck semen samples before proceeding for RNA isolation. So, initial concentration of each sample was made equal. The spermatozoa were isolated from buck semen samples by swim- up protocol using sperm TALP. Total RNA from the buck spermatozoa were extracted and first strand cDNA was synthesized from 1μg total RNA by using commercial kits. Absolute quantification of CLU gene transcripts in semen samples from 12 bulls was performed by plotting standard curve. Variations in levels of CLU gene transcripts (2500-22546000 copies) were found among 12 different buck semen samples. In vitro sperm characteristics were also studied from 12 buck semen samples. Variations in sperm characteristics such as sperm motility (60.0 - 80.0%), sperm viability (72.0 - 93.0%), sperm morphology (73.0 - 91.0%), plasma membrane integrity (50.0 - 82.0%), acrosome integrity (81.0 - 93.0%), DNA integrity (82.0 - 93.0%) and MMP (46.0 - 74.0%) were found among buck semen samples. All in vitro sperm characteristics were highly (negatively) correlated (p<0.01) with expression levels of CLU gene transcripts in spermatozoa. From this study, it is evident that ejaculated buck semen has variations in transcription pattern of CLU gene in spermatozoa among bucks and expression levels of CLU transcripts have negative correlation with in vitro sperm characteristics in buck semen samples.
ABSTRACT
The aim of the study was to evaluate the cryodamage effects on human sperm characteristics, especially on sperm DNA integrity, after 6 months of freezing comparing between liquid nitrogen vapour (LNV) and computerized program freezer (CPF). Forty normal semen samples were collected for semen analysis. Each sample was mixed with cryoprotective media and devided into 2 straws. The first straw was frozen with LNV and the second one with CPF. After 6 months of cryostorage, semen samples were thawed, and sperm chromatin integrity as well as sperm motility, morphology, vitality and cryosurvival rate were determined. Percentages of DNA damage were higher (p<0.01) following freezing with LNV than with CPF. Sperm vitality was greater (p<0.05) after CPF than after LNV, as well as cryosurvival rate (p<0.001). Post-thawed sperm motility was greater after CPF than after LNV, either in grade A (p<0.001) or in grade B (p<0.05). No significant difference was observed in the percentage of normal sperm morphology comparing the two freezing methods. The current study demonstrated post-thawed decrease in sperm DNA integrity as well as other sperm characteristics after freezing in both methods. The CPF significantly provided superior results in post-thawed sperm DNA integrity, sperm motility and vitality than LNV did. In case of 6 months of cryostorage, therefore, we recommend the computerized program freezer as a preference for sperm cryopreservation.