Targeted Glutamate Supply Boosts Insulin Concentrations, Ovarian Activity, and Ovulation Rate in Yearling Goats during the Anestrous Season.

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.

Colostrum Quality Assessment in Dairy Goats: Use of an On-Farm Optical Refractometer.

Failure of passive immunity transfer is one of the main causes of increased susceptibility to infectious agents in newborn kids. To ensure successful transfer of passive immunity, kids need to be fed high-quality colostrum, containing an adequate concentration of IgG. This work evaluated the quality of colostrum obtained in the first 3 days postpartum from Malagueña dairy goats. The IgG concentration in colostrum was measured using an ELISA as a reference method, and it was estimated by optical refractometer. Colostrum composition in terms of fat and protein was also determined. The mean concentration of IgG was 36.6 ± 2.3 mg/mL, 22.4 ± 1.5 mg/mL and 8.4 ± 1.0 mg/mL on days 1, 2 and 3 after parturition, respectively. Brix values obtained using the optical refractometer were 23.2%, 18.6% and 14.1% for days 1, 2 and 3, respectively. In this population, 89% of goats produced high-quality colostrum with IgG concentrations of >20 mg/mL on the day of parturition, but this percentage declined dramatically over the following 2 days. The quality of the fresh colostrum estimated with the optical refractometer was positively correlated with those obtained using ELISA (r = 0.607, p = 0.001). This study highlights the importance of feeding first-day colostrum to newborn kids and demonstrates that the optical Brix refractometer is suitable for the on-farm estimation of IgG content in colostrum.

Ultra-Rapid Freezing Using Droplets Immersed into Liquid Nitrogen in Bull Sperm: Evaluation of Two Cryoprotective Disaccharides and Two Warming Temperatures.

The present study analyzes the effects of different disaccharide concentrations and two thawing temperatures on the characteristics of ultrarapid frozen (URF) bovine sperm, compared with conventional slow-frozen (CF) sperm. For URF sperm, samples were diluted in media comprising 2% bovine serum albumin (BSA) and various nonpermeable cryoprotectants. Five groups were compared: control (without cryoprotectant), sucrose 0.15 M, sucrose 0.3 M, trehalose 0.15 M, and trehalose 0.3 M. In addition, the influence of warming temperatures, 37°C and 65°C, was analyzed. The aspect of different diluents (by drops) immersed in liquid nitrogen was also evaluated. Sperm quality was assessed by measuring motility, viability, acrosome status, and membrane lipid peroxidation (LPO). Moreover, the cryoresistance rate (CR) was determined. The drops immersed in liquid nitrogen showed that crystallization occurred, but not vitrification. CF sperm exhibited significantly higher scores for total motility (TM) and progressive motility (PM), viability, and acrosome integrity, in contrast with URF samples. Cryoprotectants for URF sperm showed a significant (p ≤ 0.05) influence on the TM and PM, viability, acrosome integrity, and CR, but not on LPO. Sperm viability was reduced after ultrarapid freezing, and the control samples were observed to have significantly lower values than those treated with disaccharides. Samples supplemented with 0.3 M sucrose exhibited higher LPO when they were thawed at 37°C. In short, a limited number of spermatozoa were able to maintain their motility and other functional attributes after ultrarapid freezing, but disaccharides showed a moderate protective effect. Samples with trehalose and sucrose at 0.15 and 0.3 M, respectively, showed higher sperm quality than samples containing only BSA. In sum, the function of spermatozoa was moderately maintained when disaccharides were used for ultrarapid freezing, although motility was significantly reduced. In addition, thawing temperatures did not modify the sperm values, suggesting that the easier procedure, that is, 37°C for 30 seconds, can be used.

Periovulatory Hormonal Profiles after Estrus Induction and Conception Rate by Fixed-Time AI in Payoya Goats during the Anestrous Season.

Sexual activity in domestic goats is positively influenced by reducing the photoperiod. Various protocols have therefore been developed in goats for the induction and synchronization of estrus during those months in which their sexual activity is reduced. The present observational study evaluates the periovulatory hormonal profile in Payoya goats (n = 24), during a non-favorable photoperiod (i.e., spring), being treated for estrus induction. The treatment comprised the vaginal insertion of sponges impregnated with progestogen (fluorogestone acetate, FGA), together with cloprostenol and equine chorionic gonadotrophin (eCG), 48 h before the end of the treatment. When the treatment ended, the plasma concentrations of the LH, FSH, progesterone and estradiol were determined. The goats were inseminated 46 h after the sponge withdrawal, and a pregnancy diagnosis was carried out 40-45 days after the insemination. Various parameters were monitored, such as the peaks of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol, and their respective intervals, in reference to the time of the sponge withdrawal. The conception rate was 62.5%, and the kidding rate was 50%. The results record the hormonal release pattern after the estrus synchronization treatment based on the FGA, and the differences between the pregnant and non-pregnant goats. The findings suggest that the LH peak produced after the estrus synchronization treatment, both in terms of the amplitude and the time of increment, is involved in the reproductive failure detected.

Goats as Valuable Animal Model to Test the Targeted Glutamate Supplementation upon Antral Follicle Number, Ovulation Rate, and LH-Pulsatility.

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.

Welfare Quality® for dairy cows: towards a sensor-based assessment.

This Research Reflection addresses the possibilities for Welfare Quality® to evolve from an assessment method based on data gathered on punctual visits to the farm to an assessment method based on sensor data. This approach could provide continuous and objective data, while being less costly and time consuming. Precision Livestock Farming (PLF) technologies enabling the monitorisation of Welfare Quality® measures are reviewed and discussed. For those measures that cannot be assessed by current technologies, some options to be developed are proposed. Picturing future dairy farms, the need for multipurpose and non-invasive PLF technologies is stated, in order to avoid an excessive artificialisation of the production system. Social concerns regarding digitalisation are also discussed.

Effect of olive-derived antioxidants (3,4-dihydroxyphenylethanol and 3,4 dihydroxyphenylglycol) on sperm motility and fertility in liquid ram sperm stored at 15°C or 5°C.

The aim of the present study was to evaluate the effect of the addition of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during liquid storage at 5°C and 15°C. Semen was collected, pooled, diluted and then divided into aliquots supplemented with different concentrations (5 µg/ml, 10 µg/ml, 50 µg/ml and 100 µg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. Sperm motility characteristics were assessed in the different samples at 0, 6, 24, 48, 72 and 96 hr after cooling, and a fertility trial was also conducted. The results showed that the antioxidant addition did not significantly improve total and progressive motility in ovine cooled sperm maintained at 15° or 5°C. However, in samples stored at 5°C, LIN (48, 72, 96 hr), STR (0 hr) and WOB (0, 48, 72, 96 hr) values significantly decreased in comparison with control treatment when high antioxidant concentrations were added (MIX100 or HT100). When samples were maintained at 15°C, MIX50 showed significantly higher VCL values than the control treatment after 6 hr cooling, and MIX100 showed significantly lower VCL values at 96 hr after cooling. According to the artificial insemination trial, no significant differences were observed when antioxidants were added. In conclusion, the use of HT and DHPG showed small impact in sperm motility and fertility was not affected (nor detrimentally nor positively) when insemination was carried out using antioxidant-supplemented liquid sperm.

Frozen dog spermatozoa are negatively affected during storage at -80, -21 and -8 ºC.

Cryopreservation in liquid nitrogen (LN2) allows for semen to be stored for long periods of time while there is sustaining of sperm viability. In this study, there was assessment of effects induced by different storage temperatures on cryopreserved dog spermatozoa. After cryopreservation at -196 °C, sperm samples were transferred to storage conditions of -80, 21 or -8 °C. Sperm motility, morphology, viability, acrosome integrity, mitochondrial membrane potential and DNA fragmentation were determined in samples stored at -196 °C (evaluation time =0 h), and then after 12 h and 1, 4, 7 and 15 d of storage at 80, -21 and -8 °C. In samples stored at -80 °C, sperm morphology, viability, acrosome integrity, mitochondrial membrane potential and DNA fragmentation did not differ at successive evaluation times. Progressive motility was less (P < 0.05) after 12 h and total motility after 4 d of storage at -80 ºC as compared with that of the 0 h sample. With storage at the other temperatures (-21 and -8 ºC), there was a reduction of mean values for sperm total and progressive motility, viability and mitochondrial membrane potential after 12 h of storage at these temperatures. Results, therefore, indicate the use of ultra-freezers at -80 ºC to store frozen dog semen allows for maintenance of sperm characteristics for at least 15 d but motility is sustained for only 1 d. Neither of the -21 or -8 ºC storage temperatures were effective for storing of frozen dog sperm and retaining viability.

Fertility after insemination with frozen-thawed sperm using N-methylacetamide extender on the Combatiente Español avian breed.

The aim of this study was to evaluate the in vitro and in vivo quality of frozen-thawed sperm obtained from the Combatiente Español avian breed, with sperm having previously been diluted in N-methylacetamide (NMA). Experimental groups were established: fresh control semen (C); semen diluted without cryoprotectant (T1); semen diluted with extender containing NMA (T2); frozen-thawed sperm (with NMA) containing 500 × 106 spermatozoa (T3); frozen-thawed sperm (with NMA) containing 250 × 106 spermatozoa (T4). In the different groups, sperm motility and viability were assessed using a computer-assisted semen analyzer and flow cytometer, respectively. To evaluate the fertilizing capacity of the sperm, the percentage of fertile eggs was determined. The fertility rate after insemination with frozen-thawed semen was poor, and the concentration of the inseminating dose did not affect fertility rate (9.4 ±â€¯2.7% and 7.0 ±â€¯2.3%, respectively). The results indicate insemination using diluted semen without CPA leads to a reduced fertility, and the addition of 9% NMA to the extender has a greater negative effect on this in vivo variable. Furthermore, inclusion of NMA in the freezing-thawing processes reduced capacity of sperm for fertilization. Sperm viability was reduced during the freezing process, and the dilution in NMA extender affected both sperm viability and motility. The results indicate rooster fertility is negatively affected by sperm dilution, NMA addition and the frozen-thawed effects. Frozen-thawed sperm from Combatiente Español roosters maintained fertilizing capacity for no more than 6 days after insemination, whereas for fresh sperm this capacity was maintained for 14 days.

Vitrification induces critical subcellular damages in ram spermatozoa.

The aim of the present study was to analyse morphological variations in ovine spermatozoa subjected to different cryopreservation protocols using high resolution imaging techniques. Ejaculates were pooled and diluted in Tris-based extender. Aliquots containing 300 × 106 spz/ml were prepared and evaluated a) after the semen collection and pooling, b) after conventional freezing, c) after vitrification of samples maintained at room temperature (22 °C) prior to vitrification, and d) after vitrification of samples maintained at 5 °C prior to vitrification. Sperm motility, acrosome integrity, DNA fragmentation and morphology were assessed. Subcellular sperm changes were assessed and described by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The maintenance of spermatozoa at 5 °C prior to vitrification and the use of 0.4 M sucrose pointed out lower dimensions of area, length and width than fresh, frozen and sperm maintained at 22 °C prior to vitrification. It was observed that the head width and length are significantly higher (P < 0.0001) in fresh spermatozoa than in the vitrified sperm samples. It could be hypothesized that greater intracellular fluid loss during vitrification could prevent damages in the spermatozoon throughout the reduced ice crystals formation, but mainly by the reduction of extracellular ice crystals due to the physical properties modification obtained when high concentrations of sugars are added. This is the first ultramicroscopic study carried out in ovine vitrified spermatozoa, which confirms the functional sperm alterations previously detected.

Altered testicular development as a consequence of increase number of sertoli cell in male lambs exposed prenatally to excess testosterone.

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.

Localization, distribution, and function of the calcium-sensing receptor in sperm.

The intracellular movement of calcium, through calcium channels, plays a major role on sperm cell function. The calcium-sensing receptor (CaSR), a molecular mechanism by which many cells detect changes in extracellular calcium concentration, has not been described in spermatozoa. The aim of this study was to investigate the expression of the CaSR in testicular tissue and sperm cells and the functional consequences of spermatozoid CaSR activation by calcimimetics. CaSR mRNA and protein were identified both in rat testicular tissue and in rat spermatozoa using real-time reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. Functionality of CaSR was evaluated by studying the influence of calcimimetic AMG 641 on rat and pig sperm motility. Treatment with AMG 641 100 nM for 1 hour increased rat sperm motility from a score of 1.0 ± 0.1 to 3.8 ± 0.3 (P < .05). AMG 641 also resulted in a modest but significant increase in the pig sperm motility parameters evaluated by computer-assisted sperm analysis. AMG 641 was effective in a wide range of concentrations but resulted in a more marked effect at 50-100 nM. In addition, AMG 641 did not have any negative effect on sperm viability, which was measured by flow cytometry. In conclusion, our results demonstrate the expression of functional CaSR in testicular tissue and sperm, which can be activated by calcimimetic AMG 641.