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The decrease in fertility in aging roosters is related to the reduced quality of ejaculated sperm. This study aimed to investigate the effect of dietary supplementation with ginseng extract at various concentrations (0-150 mg/kg) on testicular function, semen preservation, and fertility at different stages of sexual maturity (mature and aging roosters) in Thai native roosters. Pradu Hang Dum roosters at 32 (mature; n = 24) and 75 (aging; n = 24) weeks of age were fed diets with non-supplemented or supplemented ginseng extracts (50, 100, and 150 mg/kg) until the end of the experiment. In experiment 1, fresh semen samples were examined for the quality parameters of semen volume, sperm concentration, sperm motility, sperm viability, lipid peroxidation, and enzymatic activities. In experiment 2, semen was preserved at 5 °C for up to 48 h, and the semen quality and fertility potential were determined. In experiment 3, testicular function and testosterone concentrations were evaluated. The results showed that ginseng extract supplementation in the diets of both mature and aging roosters at 50 and 100 mg/kg improved fresh semen quality (P < 0.05). A decrease in malondialdehyde levels in fresh semen was observed with increasing enzyme activities. In mature roosters, the progressive motility of cold-stored semen and fertility rates were higher in the G50 and G100 groups compared to the control and G150 groups after 24 h of storage (P < 0.05). In aging roosters, the highest significant differences in progressive motility, viability, and fertility rates were observed in the G50 and G100 groups at all storage times (P < 0.01). These improvements might be attributed to good testicular function in spermatogenesis, as revealed by the results of histological examination and testosterone concentrations. However, higher doses of ginseng extract supplementation negatively affected sperm quality. In summary, the recommended dose of ginseng extract supplementation in diets is 50 mg/kg. Fertility results indicated that insemination with semen preserved for 24 h was satisfactory in both mature and aging roosters.

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BACKGROUND: Contradictory data have been reported about the association between testosterone levels and the levels of low-density lipoprotein cholesterol (LDL). OBJECTIVES: The aim of this study was to elucidate the association between testosterone and LDL levels. MATERIALS AND METHODS: A cross-sectional study was conducted that included 7268 men who had participated in a health examination. Men who took agents that influence serum lipid profiles within the previous 6 months were excluded. A full metabolic work-up and serum testosterone level checks were performed. The main outcome measures included the testosterone level and testosterone <3.5 ng/ml prevalence of each decile of LDL and their polynomial trendlines and the odds ratio (OR) of testosterone <3.5 ng/ml according to the LDL level. RESULTS: The polynomial trendline suggests the inverse association of testosterone with the deciles of triglycerides, the positive association of testosterone with the deciles of high-density lipoprotein cholesterol and the inverted U-shaped association between testosterone and the deciles of LDL. The polynomial trendline suggests a U-shaped curvilinear relationship between the deciles of LDL and the prevalence of testosterone <3.5 ng/ml. The adjusted ORs of testosterone <3.5 ng/ml in men in the lowest and highest deciles were significantly higher than those of men in the 10th-90th deciles of LDL (OR [95% CI], < 10th LDL: 1.4[1.2-1.8]; 10th - 90th LDL: 1.0 [reference]; >90th LDL: 1.3[1.0-1.6]), which reinforces the U-shaped curvilinear relationship between LDL levels and the prevalence of testosterone <3.5 ng/ml. DISCUSSION AND CONCLUSION: Further research is needed to elucidate the association of very low or very high LDL concentrations with circulating testosterone in men.

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OBJECTIVE: To investigate the relation between serum zinc concentration and several factors, including serum testosterone concentration and the score of questionnaires on sexual function in patients with sexual problems. METHODS: This study comprised 720 men (age, 46.3 [21-83] years) with some kind of sexual problem. Age, scores of the Sexual Health Inventory for Men and the Erection Hardness Score, and endocrinologic data including serum concentrations of testosterone, prostate-specific antigen, and zinc were included in this study. After serum zinc concentration of the men was classified into 5 groups (<70, 70≤ <80, 80≤ <90, 90≤ <100, ≤100 µg/dl), the relation of each parameter with serum zinc concentration was assessed for a trend analysis. Finally, the relation between serum concentrations of zinc and testosterone as well sexual function evaluated by the scores of the questionnaires was investigated. RESULTS: Only serum testosterone concentration (ptrend = 0.028) and serum cortisol concentration (ptrend = 0.003) showed a statistically significant relation to serum zinc concentration by trend analysis. Interestingly, trend analysis between serum concentrations of testosterone and zinc still showed a significant association after adjustment for serum cortisol concentration (ptrend = 0.032). However, no significant association was found in the relation between serum zinc concentration and the scores of the questionnaires after adjustment for serum concentrations of testosterone and cortisol. CONCLUSION: We clearly showed that after adjustment for serum cortisol concentration by trend analysis, serum testosterone concentration decreased as serum zinc concentration decreased, although sexual symptoms were not associated with this decrease.

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Thirty healthy Sohagi ram lambs with an average age of 188.6±7.3 days were used to study the effect of pre-pubertal growth rate on some physiological parameters and sexual behavioral patterns at puberty. Ram lambs were divided into three groups (10 animals per each group) according to the previous growth rate until 6 months of age. Groups were marked as fast, medium and slow growing. Animal groups were housed in closed barns with access to an open area. Results showed that age and weight of ram lambs at puberty were significantly affected (P<0.05) by the pre-pubertal growth rate. Ram lambs in the fast growing group were reached to onset puberty firstly at 272.6 days with body weight (BW) 37.1 kg on average then ram lambs in medium group (284.8 days with BW 32.7 kg), while ram lambs in slow growing group were the last (314.1 days with BW 32.5 kg). Blood testosterone concentration at puberty was not significantly different among growing groups (1.494± 0.03 ng/ml on average, ranged from 1.287 to 1.902 ng/ml). Testes measurements from 6 months of age until puberty show that ram lambs in fast growing group had the highest values of testes length, circumference and volume followed by those in medium and slow growing group. Sexual behavioral observation showed that flehmen and mounting behavior were significantly higher for ram lambs in fast growing group (5.63 and 6.75 number/12h) than slow growing group (4.25 and 5.38 number/12h) while in medium growing group were intermediate (4.88 and 5.88 number/12h). From these findings, could be concluded that age, weight and sexual behavioral patterns of Sohagi ram lambs at puberty were affected by pre-pubertal growth rate, and the breeders should strive to achieve good growth rates for their lambs before puberty which led to improving reproductive performance.

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Chronic use of GnRH agonists and immunization against GnRH have been used as reversible contraceptive methods. The aim of this study was to compare the effectiveness of both treatments to inhibit reproductive function of adult bucks, in terms of strength and duration of the effects. We used 9 control untreated bucks (CON), 7 bucks treated chronically with a GnRH agonist (subcutaneous implants with 7.4 mg of deslorelin, Suprelorin, Virbac) (AGO), and another 7 bucks were immunized against GnRH (dose of 2 mL of Improvac-Zoetis with 300 µg of a synthetic incomplete analog of natural GnRH; 300 mg of diethylaminoethyl-dextran; and 2.0 mg of chlorocresol) (IMM). Testicular and sperm evaluations, testosterone concentrations, and male odor were determined from 4 wk before applying the treatments until 17 mo of their application. Scrotal circumference of CON (21.0 ± 0.1 cm) and IMM (21.2 ± 0.2 cm) was greater than that of AGO bucks (19.9 ± 0.2 cm) (P < 0.05 for each), without difference between CON and IMM bucks. Pixels' color intensity of testicular ultrasound images was not affected by treatment (general mean ± SEM: 116.0 ± 1.8). Testosterone concentration was greater in CON than AGO and IMM in months 3 and 4, greater in CON and IMM than AGO bucks in months 15 and 16, and greater in IMM than CON and AGO bucks in month 17 (P < 0.05 for all comparisons). Male odor was greater in CON (1.5 ± 0.0) than IMM bucks (1.3 ± 0.0) and greater in IMM than AGO (1.1 ± 0.0) bucks (P < 0.05 for each). Treatment negatively affected all the sperm variables: the total number of sperm in the ejaculate, sperm motility, sperm with normal morphology and sperm with integral membrane function. It was concluded that both treatments were effective in inhibiting the reproductive axis; however, neither of them produced azoospermia or decreased testosterone concentrations to undetectable levels. With both treatments, there were individual males exhibiting characteristics of fertility in all periods of the study. However, chronic use of a GnRH agonist seemed to be the most effective treatment in terms of duration and strength.

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