EFFECT OF GnRH ANALOGUE ON LIBIDO AND SEMEN CHARACTERISTICS OF PUBERAL BUFFALO BULLS (original) (raw)
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Animal Reproduction Science, 2018
The aim of this study was to determine if daily administration of a GnRH analogue (buserelin acetate) to bucks during the non-breeding season increases testosterone concentration and improves sperm quality. Five bucks received a daily dose of buserelin for 10 days, starting on Day 0 (first administration), and another five bucks remained as controls. Testosterone concentrations were greater in treated than in control bucks during the first hours after administration (P = 0.05), but greater in controls 12 h later (P < 0.01). Sperm mass motility and percentage of motile sperm were greater in treated (3.9 ± 0.6 and 70.1 ± 7.9%, respectively) than in control bucks (1.0 ± 0.6, P < 0.01; 45.0 ± 7.9%, P < 0.05 respectively) on Day 4. Percentage of sperm with normal morphology tended to be greater in treated than in control bucks (81.8 ± 6.2% compared with 63.5 ± 6.4 % respectively, P = 0.08). The treatment decreased the percentage of sperm with mid piece defect and with bent tail (7.0 ± 1.5% compared with 12.0 ± 1.5%; 8.0 ± 1.7% compared with 13.5 ± 1.7%, treated and control bucks, respectively, P = 0.05 for both). The square root percentage of sperm with loose but heads with normal structures tended to be less in treated than control bucks (1.3 ± 0.3% compared with 0.4 ± 0.3% respectively, P = 0.06). It was concluded that daily administration of buserelin during the non-breeding season led to a rapid increase in testosterone concentration and improved sperm quality.
Research in Veterinary Science, 2015
GnRH treatment has been suggested to increase testosterone levels temporarily and to stimulate libido in stallions, but its use has not fully ascertained in dromedary camels. The aim of this work was to study the effects of administering 100 µg of GnRH on testosterone profile, libido and semen parameters in dromedary camels. The same bulls were used as self-controls and experimental group. Blood samples were collected every 20 minutes (T0-T12) for 4 hours, and semen collections were performed over a 2-hour period after T12. GnRH was administered immediately after T0. In GnRH-treated bulls, testosterone levels showed an upward trend, peaking after 140 minutes, and then slowly decreasing. GnRH administration also led to a decrease in mating time and an increase in spermatozoa concentration. Overall, it seems that administration of 100 µg GnRH might increase testosterone levels temporarily and enhance camel reproduction performance.
The present study aims to investigate the Luteinizing hormone (LH), testosterone and total estrogens response to exogenous gonadotropin-releasing hormone (GnRH) in adult crossbred bulls with differing semen quality. Fourteen adult crossbred bulls of differing semen quality were selected and treated with 10 mg of GnRH (Buserelin acetate) intramuscularly. Blood samples of the bulls were collected at an interval of 30 min commencing 1 h prior to GnRH treatment until 4 h post-GnRH treatment and thereafter, at an interval of 1 h for the next 3 h. The endocrine response in terms of peak values, area under the curve, and the time taken to attain peak values for LH, testosterone, and total estrogens were evaluated in all the bulls. The mean 7 SEM peak levels of LH, testosterone, and total estrogens were found to be 150 7 24.1, 5.3 7 0.69, and 0.077 0.01 ng/mL, respectively. The mean 7 SEM area under the curve of LH, testosterone, and total estrogens were found to be 392 7 51.3, 23.57 3.4, and 0.32 7 0.04 ng/mL Â h, respectively. The relationships between hormonal responses (LH, testosterone, and total estrogens) and semen quality were analyzed using the linear regression method, which provided nonsignificant (P 40.05) results. This study indicated that the gonadal and pituitary hormonal response to single exogenous GnRH treatment may have no relationship with the semen quality of crossbred bulls.
Journal of Reproduction and Development, 2011
The present study investigated the basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality. On the basis of semen parameters, bulls (n=5) having poor semen quality were selected as experimental bulls, and good semen quality bulls (n=4) were used as control bulls. Both groups were treated intramuscularly once with GnRH (250 μg of fertirelin acetate). Blood samples were collected at-1 day (d),-30 min and 0 h (treatment) followed by every 30 min for 5 h and 1, 3 and 5 d post-GnRH treatment (PGT), and LH, testosterone and estradiol-17β (E2) concentrations were measured. The pretreatment concentrations were used as basal levels. The percentage increments based on the 0-h levels were calculated per bull for each sampling time until 5 h PGT, and differences were compared between the experimental and control groups. The PGT concentrations of testosterone and basal and PGT concentrations of E2 were significantly lower in the experimental group. The testosterone increment in the experimental group was delayed and significantly lower from 1 to 5 h PGT than those in the control group. It can be suggested that bulls with poor semen quality have delayed and lower GnRH-induced testosterone response and may also have lower estrogen levels.
Jurnal Ilmu Ternak dan Veteriner, 2021
Bali cattle are one of the original Indonesian germplasm, which in its development were found to be hornless or polled. Polled are Balinese cattle whose horns do not grow naturally, but have the same characteristics as those with horns. However, there are indications that polled have a lower libido. The purpose of this study was to determine the characteristics of libido and testosterone concentration after gonadotrophin releasing hormone (GnRH) injection. In this study each of 7 male polled and horned Bali cattle aged 3.5-6 years were used. Libido characteristics were observed by recording the first time the male fondled the teaser until ejaculation, while the testosterone concentration was measured using blood plasma taken on day 0 or before injection, day 7th, and day 14th after GnRH injection. Testosterone analysis used enzyme linked immunosorbent assay (ELISA) method. The results showed that the libido of polled was not different (P>0.05) compared to that of the horned on th...
Theriogenology, 1995
The investigation of the fertility capacity of A.I. bulls is one of the most important factors in their genetic improvement. The aim of this study was to examine the relationship between the results of the GnRH test and the measured and calculated size of the testicles and sperm parameters (sperm density and velocity, percentage of live and motile spermatozoa). Data was collected during three experiments from a total of 81 Holstein-Friesian breeding bulls at the National Artificial Insemination Centre of Hungary. In Experiment I. a very close correlation (r=0.64, p<O.OOl ; r=0.66, p<O.OOl ; r=0.99, p<O.OOl; r=0.75, pcO.001) was found between the size of testes (weight, volume, width, length) and the calculated volume. According to the data, we may calculate volume based on the width of testicles measured by sonography.
Effect of prostaglandin F2 alpha on libido, seminal quantity and quality of buffalo bulls
Theriogenology, 1986
Four mature Murrah buffalo bulls on a regular semen collection schedule of twice a day, two days per week, were injected with 30 mg prostaglandin F2 alpha THAM salt(PGFj intramuscularly 30 minutes prior to eQCh alternate first ejaculation for six weeks. Effects uf PGF on time to initial false mount on the decoy, time to ejaculation after two false mounts (reaction time), seminal volume, sperm concentration, total sperm output, motility of fresh and thawed semen and the semen doses obtained per collection were evaluated. Treatment CQuSed significant (P < 0.01) reduction in the time to first false mount and the reaction time for the first ejaculations but had no effect (P > 0.05) on these for the second ejaculations. Values for other quantitative and qualitative parameters did not differ (P > 0.05) due to PGF treatment. It is concluded that PGF at the dosage Qnd frequency of administration used may be of some value in improving libido in low-libido bulls but does not alter the reproductive capacity of buffalo bulls.
Reproduction, 2003
Administration of GnRH agonist for an extended period inhibits pulsatile LH release but enhances testicular function of bulls. The mechanism whereby long-term administration of GnRH agonist enhances testosterone concentration in the blood of bulls has not been determined. The aim of this study was to determine whether chronic treatment with the GnRH agonist, azagly-nafarelin, increases blood concentrations of LH and FSH in prepubertal bulls. Two different doses of the GnRH agonist were administered via Alzet mini-osmotic pumps for 28 days. Blood samples were collected at 20 min intervals for 24 h at days 2, 13 and 25 of treatment. Agonist-treated groups had reduced testosterone pulse frequency (P < 0.05) and increased mean and basal concentrations of testosterone (P < 0.05) compared with untreated control bulls. Basal LH concentrations were higher in agonist-treated bulls during all three periods (P < 0.05) and overall (1 ng ml −1 higher, compared with control bulls; P < 0.001). Frequency of LH pulses in the agonist-treated groups was reduced to less than one pulse in 24 h. Agonist-treated bulls tended to have (P < 0.10) or had (P < 0.05) a slight but significant increase in blood FSH concentration. In conclusion, the higher blood testosterone concentration in bulls after prolonged treatment with GnRH agonist may result, at least in part, from changes in the testes induced by enhanced basal concentration of LH.