RESUMO
The neuroendocrine regulation of the seasonal reproductive axis requires the integration of internal and external signals to ensure synchronized physiological and behavioral responses. Seasonal reproductive changes contribute to intermittent production, which poses challenges for optimizing goat product yields. Consequently, a significant objective in seasonal reproduction research is to attain continuous reproduction and enhance profitability in goat farming. Glutamate plays a crucial role as a modulator in several reproductive and metabolic processes. Hence, the aim of this study was to evaluate the potential impact of exogenous glutamate administration on serum insulin concentration and ovarian function during the out-of-season period in yearling goats. During the anestrous season, animals were randomly located in individual pens to form two experimental groups: (1) glutamate (n = 10, live weight (LW) = 29.1 ± 1.02 kg, body condition score (BCS) = 3.4 ± 0.2 units) and (2) control (n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2), with no differences (p < 0.05) regarding LW and BCS. Then, goats were estrus-synchronized, and blood sampling was carried out for insulin quantification. Ovaries were ultrasonographically scanned to assess ovulation rate (OR), number of antral follicles (AFs), and total ovarian activity (TOA = OR + AF). The research outcomes support our working hypothesis. Certainly, our study confirms that those yearling goats treated with exogenous glutamate displayed the largest (p < 0.05) insulin concentrations across time as well as an augmented (p < 0.05) out-of-season ovarian activity.
RESUMO
The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic−hypophyseal−ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications.
RESUMO
The present study was conducted to establish the normal values of the combined thickness of the uterus and placenta (CTUP) in Spanish Purebred maresduring late pregnancy. A total of 107 mares were examined at 210, 240, 270 and 300 days of gestation, of which 13 had abnormal gestations (foetal death, abortion or stillbirth). In mares with healthy foals, CTUP measurements showed significant differences (P < 0.0001) at the various gestational ages (4.83 ± 0.59 mm, 6.12 ± 0.60 mm, 7.41 ± 0.61 mm and 10.45 ± 0.92 mm at 210, 240, 270 and 300 days, respectively). A high positive correlation was observed between CTUP and gestational age (r = 0.923; P < 0.001). In mares with abnormal gestation, CTUP measurements were significantly (P < 0.0001) higher than in healthy gestations at day 270 (8.89 vs.7.41 mm) and day 300 (14.17 vs. 10.45 mm). The age of the mare, fertilization time, type of semen and gestation length did not affect the CTUP. The results obtained suggest that the cut-off point for detecting abnormal pregnancies in Spanish Purebred mares is 7.75 mm on day 270 and 12.7 mm on day 300. The authors find that the incidence of placental thickness enlargement in the late gestation of Spanish Purebred is 14%, and a transrectal ultrasonographic examination is highly advisable at 270 days of gestation. Such timely placental assessment could reveal otherwise undetected disorders, thereby enabling early and proper treatments to be administered to prevent foetal loss.(AU)
Assuntos
Animais , Feminino , Cavalos/anatomia & histologia , Cavalos/fisiologia , Ultrassonografia/métodosRESUMO
The present study was conducted to establish the normal values of the combined thickness of the uterus and placenta (CTUP) in Spanish Purebred maresduring late pregnancy. A total of 107 mares were examined at 210, 240, 270 and 300 days of gestation, of which 13 had abnormal gestations (foetal death, abortion or stillbirth). In mares with healthy foals, CTUP measurements showed significant differences (P < 0.0001) at the various gestational ages (4.83 ± 0.59 mm, 6.12 ± 0.60 mm, 7.41 ± 0.61 mm and 10.45 ± 0.92 mm at 210, 240, 270 and 300 days, respectively). A high positive correlation was observed between CTUP and gestational age (r = 0.923; P < 0.001). In mares with abnormal gestation, CTUP measurements were significantly (P < 0.0001) higher than in healthy gestations at day 270 (8.89 vs.7.41 mm) and day 300 (14.17 vs. 10.45 mm). The age of the mare, fertilization time, type of semen and gestation length did not affect the CTUP. The results obtained suggest that the cut-off point for detecting abnormal pregnancies in Spanish Purebred mares is 7.75 mm on day 270 and 12.7 mm on day 300. The authors find that the incidence of placental thickness enlargement in the late gestation of Spanish Purebred is 14%, and a transrectal ultrasonographic examination is highly advisable at 270 days of gestation. Such timely placental assessment could reveal otherwise undetected disorders, thereby enabling early and proper treatments to be administered to prevent foetal loss.
Assuntos
Feminino , Animais , Cavalos/anatomia & histologia , Cavalos/fisiologia , Ultrassonografia/métodosRESUMO
The reprograming effects of prenatal testosterone (T) treatment on postnatal reproductive parameters have been studied extensively in females of several species but similar studies in males are limited. We recently found that prenatal T treatment increases Sertoli cell number and reduced spermatogenesis in adult rams. If such disruptions are manifested early in life and involve changes in testicular paracrine environment remain to be explored. This study addresses the impact of prenatal T excess on testicular parameters in infant males, including Sertoli cell number and expression of critical genes [FSH receptor (FSHR), androgen receptor (AR), transforming growth factor beta 1 (TGFB1), 3 (TGFB3), transforming growth factor beta type 1 receptor, (TGFBR1), and anti-Müllerian hormone (AMH)] modulating testicular function. At 4 week of age, male lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T-males), had a higher number of Sertoli cells/testis (P = 0.035) than control males (C-males) born to dams treated with the vehicle. While no differences were observed in the expression of FSHR and TGFB3, testicular TGFBR1 expression was found to be lower in T-males (P = 0.03) compared to C-males. Expression level of AMH, TGFB1, and AR also tended to be lower in T-males. These findings provide evidence that impact of fetal exposure to T excess is evident early in postnatal life, mainly characterized by an increase in Sertoli cell number. This could explain the testicular dysfunction observed in adult rams.