The objective of this study was to determine the ability of prostaglandin E2 (PGE2) to induce ovulation and expression of PGE2 receptor (EP2 and EP4) and COX genes (COX-1 and COX-2) in the ovary and pituitary of prepubertal mice. The positive control consisted of the application of 5 μg of gonadotropin-releasing hormone (GnRH, n = 29); the negative control applied 0.5 mL of phosphate buffered saline (PBS, n=31); the treatment tested the application of 250 μg of PGE2 (n = 29), making a total of 89 prepubertal mice (BALB/c). Mice were euthanized 14 to 15 h after treatments to detect ovulation and tissue collection. A Chi-square test was used to compare the proportion of animals ovulating. Gene expressions and number of ovulation were analyzed by one-way ANOVA and Tukey’s test was used to compare means among groups. A greater proportion of mice (P < 0.001) ovulated after receiving GnRH (89.7%, 26/29) compared to PGE2 group (58.6%, 17/29). However, the proportion was higher compared to those treated with PBS (0%, 0/31). Ep2 gene expression in the pituitary was > two-fold higher (P < 0.05) in the PGE2 group compared to the PBS and GnRH groups. Further, PGE2 stimulated Cox1 (2.7 fold, P < 0.05) while GnRH stimulated Cox2 expression (6.5 fold, P < 0.05) in the pituitary when compared to the PBS group. In conclusion, our results support the hypothesis that PGE2 can induce ovulation in prepubertal mice with a concomitant increase in Ep2 and Cox1 gene expression in the pituitary gland.

Buffaloes mostly suffer from delayed puberty, anestrus, sub–estrus, summer infertility, prolonged inter-calving interval and postpartum uterine disorders. Nesfatin-1 and Leptin are directly or indirectly related with body weight (BW), feed parameters and regulation of puberty. The objective of this study was to investigate the influence of Nesfatin-1 and Leptin in pubertal and non-pubertal Murrah buffalo heifers. The Murrah buffalo heifers (n=13) were randomly selected and divided into two groups; pubertal group (PG) and non-pubertal group (NG). Heifers with plasma progesterone (P4) level of ≥1 ng/mL were classified as PG. Blood samples were collected at fortnight intervals for analysis of plasma Nesfatin-1, Leptin, P4, glucose and non-esterified fatty acids. Body weight, dry matter intake and feed conversion efficiency were recorded at fortnight intervals. The mean (±SEM) plasma Nesfatin-1, Leptin, P4, BW and feed conversion efficiency (%) were significantly (P<0.01) higher in PG as compared to NG. Dry matter intake by the heifers was also significantly (P<0.001) higher in PG than NG. Plasma metabolites (glucose and NEFA) did not differ significantly between the groups. The findings of this study suggest that Nesfatin-1 and Leptin have indispensable role in the onset of puberty in buffalo heifers by affecting BW and feed parameters.

From 2 to 4.5 months of age, 80 crossbred gilts were reared in a conventional grower unit where they were naturally exposed to mycoplasmal and bacterial pathogens that cause pneumonia and atrophic rhinitis. At 4.5 months of age, gilts were moved to environmentally regulated rooms (4.9 X 7.3 m) and assigned at random to 1 of 2 treatment groups: low aerial concentration of ammonia (4 to 12 ppm; mean, 7 ppm) or moderate aerial concentration of ammonia (26 to 45 ppm, mean, 35 ppm). Low concentration of ammonia was obtained by flushing of manure pits weekly, whereas moderate concentration of ammonia was maintained by adding anhydrous ammonia to manure pits that were not flushed. Gilts were weighed biweekly. Mean daily gain (MDG) was less (P < 0.01) for gilts exposed to moderate concentration of ammonia than for gilts exposed to low concentration of ammonia after 2 weeks in their respective environments. By 4 and 6 weeks, however, MDG was similar between the 2 treatment groups. After 6 weeks in these environments, 20 gilts from each treatment group were slaughtered, and prevalence and severity of lung lesions and snout grades were determined. At slaughter, body weight was greater (P < 0.01) in gilts exposed to low, rather than moderate, ammonia concentration (94.5 vs 86.8 kg; SEM, 3.3 kg). Percentage of lung tissue containing lesions (18 vs 12) and snout grade (2.8 vs 3.1) were similar between gilts exposed to low or moderate concentration of ammonia. The remaining 20 gilts in each treatment group were maintained in their respective environments, exposed daily to mature boars and bred at first estrus. Age at puberty was similar between gilts exposed to low or moderate concentration of ammonia (208 vs 205 days; SEM, 1.3 days), even though weight at puberty was less (P < 0.03) for gilts exposed to low concentration of ammonia than for gilts exposed to moderate concentration of ammonia (109.7 vs 118.2 kg; SEM, 4.5 kg). At day 30 of gestation, number of live fetuses (10.6 vs 11.7), fetal length (2.53 vs 2.57 cm), and fetus-to-corpus luteum ratio (0.85 vs 0.78) were similar between gilts at low and moderate ammonia environments. These data indicate that exposure of gilts to mean aerial ammonia concentration of 35 ppm in environmentally regulated rooms depressed MDG for 2 weeks, but failed to alter onset of puberty or litter size at day 30 of gestation.

This study aimed to determine testicular blood flow with semen imaging and describe accompanying variations in mediastinal thickness (MT), serum testosterone, and semen characteristics in Baladi bucks approaching puberty and sexual maturity. From 5–10 months of age, Baladi bucks (n = 5) underwent B-mode imaging, Doppler scanning, and blood sampling for testosterone assaying once a month. From 7 months, semen was collected and evaluated. The first semen was collected at a mean age of 7.2 months, while the first spermatozoa appeared at 8.3 months, and the mean age of sexual maturity was 9.4 months. The highest semen volume (1.02 ± 0.09 mL), motility (mass score = 5 and individual = 78.00 ± 1.58%), morphology (94.74 ± 1.99%), alive% (85.21 ± 1.32), and semen concentrations (5.24 ± 0.32 109/mL) were noted in buck 4 (9.5 months; 25.0 kg) followed by others. Testicular width (TW) and MT were positively correlated (r = 0.71; P = 0.03) and increased from 8–10 months (P < 0.05). The spectral graph of young bucks revealed an absent end velocity point. Testicular flow expressed by colored area/pixels was positively correlated with age (r = 0.855), accompanied by increased testosterone levels. Semen characteristics and Doppler parameters were not significantly correlated, except Doppler indices negatively correlated with progressive motility percentage. In conclusion, only the testicular Doppler indices are useful for evaluating testicular function and selecting bucks for breeding since these were the only variables negatively correlated with progressive motility percentage. The spectral Doppler velocities are not useful in estimating the full picture of semen quality in sexually mature bucks. These values should be assessed cautiously since many alterations could lead to the elevation or decline of testicular Doppler parameters.

This study aimed to compare the testicular morphometry, mediastinum thickness, hormonal levels, hemodynamic, echogenicity, and heterogeneity in Baladi bucks at prepubertal and postpubertal stages. Five bucks (Capra hircus) were evaluated in two different stages of growth: prepubertal (age 4.5± 0.6 months; 15.0 ± 3.0 kg) and post-pubertal stages (age 13.0 ± 1.3 months; 33.0 ± 2.5 kg). Scrotal circumference, testicular dimensions, mediastinum thickness, echogenicity, heterogeneity, Doppler parameters, semen collection, testosterone, estradiol, follicle-stimulating hormone (FSH), luteinizing hormones (LH), and nitric oxide metabolites (NOMs) were measured. There was an (P<0.05) elevation of the testicular length, width, and scrotal circumference. Mediastinum thickness and colored areas toward and away from probe were increased (P<0.05) in post-pubertal age (2.18±0.01, 6556±32.58, and 7845±65.44) compared to pre-pubertal one (1.27±0.96, 4290±42.12, and 5144±54.24). The spectral graph was characterized by low resistance (RI), moderate pulsatility (PI) with high peak velocity, and low endpoints in the post-pubertal stage while the endpoint was equal to zero in young bucks. The post-pubertal age was associated with a marked decline (P<0.05) in echogenicity, heterogeneity, and RI, while estradiol, testosterone, and NOMs levels were increased (P<0.05). It could be concluded that the post-pubertal stage in Baladi bucks is associated with changes in testicular width, length, mediastinum thickness, RI, scrotal circumference, echogenicity, pixel heterogeneity, testicular colored area away and toward the probe, end-diastolic point, testosterone, nitric oxide, and estradiol levels, as all those variables are considered an accurate markers for the onset of sexual maturity in Baladi bucks.