<p class="00-6Abstrak2Wtz">Male fertility is affected by quantity and quality of sperm which controlled by androgens (testosterone and 5α-dihydrotestosterone) mediated by androgen receptors (AR). Androgen receptors belong to receptor group of steroid hormone and a group of ligand-activated nuclear receptor superfamily. This paper explains androgen hormone and its regulation in spermatogenesis to increase male fertility. Regulation of androgen hormone in spermatogenesis include initiation of spermatogenesis, proliferation and maturation of Sertoli cells, germ cell development, spermatogonia, meiosis, and spermiogenesis. The role of androgen hormone in regulation of spermatogenesis is influenced by AR, luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels. Disruption of spermatogenesis will cause low male fertility. However, low concentrations of AR, LH and FSH could be enhanced by exogenous gonadotrophine releasing hormone (GnRH), LH, FSH, and testosterone to increase male fertility.</p>

This study was conducted to investigate the effects of sericin on meiotic maturation, hydrogen peroxide (H 2 O 2) concentration and deoxyribonucleic acid (DNA) fragmentation in buffalo oocytes. Oocytes were matured in vitro in tissue culture medium (TCM-199) with in vitro maturation (IVM) groups under several conditions, namely without bovine serum albumin (-BSA), (+BSA), and 0.025%, 0.05%, 0.1% and 0.25% (w/v) sericin. The results showed that supplementation of the maturation medium with 0.05% sericin significantly increased the rate of oocytes that reach metaphase II compared with other groups, except for the 0.025% sericin-treated group. Intracellular H 2 O 2 concentrations in oocytes of all groups were measured using 2',7'-dichlorodihydrofluorescein diacetate (DCHFDA). The concentration of H 2 O 2 in matured oocytes treated with 0.05% sericin was lower than in other groups. DNA fragmentation and the nuclear status of oocytes were examined using the terminal deoxyribonucleotidyl transferase-mediated dUTP digoxigenin nick end-labelling (TUNEL) method. The total proportion of TUNEL-positive oocytes at the MII stage was lower in the 0.05% sericin group. The results indicate that addition of 0.05% sericin to the maturation medium may improve nuclear maturation and may inhibit DNA fragmentation in oocytes by decreasing H 2 O 2 concentrations.

Bali cattle as one of Indonesia’s native cattle have horns basically, both male and female. However, in its development, Bali cattle without horns have been found and known as polled. Bali polled is cattle whose horns do not grow naturally. The objective of this study was to determine the characteristics of libido and the concentration of testosterone in Bali polled and horned bulls. The samples were 8 individuals (4 polled and 4 horned) with an age between 3-8 years. Libido characteristics were measured by recording the time the bull first fondled the cow until ejaculate and analyzing the testosterone concentration using the enzyme-linked immunosorbent assay (ELISA) method. The collected data were analyzed by an independent sample T-Test. The results of this study indicated that the time required for a polled bull from fondling the female to ejaculation was longer (P<0.05) compared to horned (7.45±2.51 vs 2.42±0.60 minutes). While the testosterone concentration was not significantly different (P>0.05) 6.94±2.43 ng/mL vs 3.74±1.34 ng/mL although showed a higher tendency for the horned bull at 3.2 ng/mL. In conclusion, the polled bull took a longer time from fondling the female to ejaculation compared to horned, while the concentration of the hormone testosterone was equal. However, libido characteristics have a positive correlation with the testosterone concentration with a correlation coefficient of 0.805.

ABSTRACT

This study aims to determine the ability of in vitro embryo cleavage of Bali cattle 48 hours after the fertilization process based on different ovarian reproductive status. Ovaries from abattoirs are grouped into four categories: ovaries without corpus luteum and dominant follicles (-CL and -FD), without corpus luteum and with dominant follicles (-CL and + FD), with corpus luteum and without dominant follicle (+ CL and -FD), and with corpus luteum and dominant follicles (+ CL and + FD). After that, oocytes are collected by slicing and only oocytes with a cytoplasmic are homongent and have compact cumulus cells used in the study. The selected oocytes are then matured in an incubator of 5% CO2, a temperature of 38.5 °C for 24 hours. After maturation, in vitro fertilization was carried out using fertilization media with a final concentration of spermatozoa 1.5 x 106 spermatozoa/ml. Oocytes 5-6 after fertilization were washed 3 times using CR1aa media then cultured in 5% CO2 incubator, temperature 38.5 °C for 48 hours. After 48 hours the culture was evaluated for the ability of embryo cleavage. The results showed that the number of embryos capable of cleave to stage 2 cells were not significantly different (P>0.05) in all treatments (1.64 ± 0.38% vs 8.00 ± 0.90% vs. 4.85 ± 0.96% vs. 8.22 ± 1.86%), while the number of embryos capable of cleave reached stage 4 cells (11.48 ± 0.82% vs 24.00 ± 2.64% vs. 24.27 ± 2.23% vs. 10.96 ± 0.69%), 8 cells (11.48 ± 1.15% vs 8.00 ± 1.07% vs. 26.21 ± 2.79 % vs 15.07 ± 1.40%), 16 cells (0.00 ± 0.00% vs 1.33 ± 0.38% vs. 4.85 ± 0.76% vs. 1.37 ± 0.38%), and the ability of embryos cleavage (24.59 ± 11.60% vs 41.33 ± 24.32% vs. 60.19 ± 22.45 % vs. 35.62 ± 10.83%) was significantly higher (P<0.05) in the ovaries with corpus luteum and without dominant follicles (+ CL and – FD). Conclusion, the ability of embryo division to reach 4 cells, 8 cells, and 16 cells after 48 hours culture was higher in the ovaries with corpus luteum and without dominant follicles (+ CL and – FD).