Resumo em Inglês:

Abstract Since bull fertility prediction remains challenging, the identification of potential fertility markers is important considering the economic benefits to the livestock industry. The main goal of this study was to determine the Na/K-ATPase activity and expression in thawed sperm of high (HF)- and low-fertility (LF) Angus bulls. Samples from three different batches/bulls with HF (n = 4) and LF (n = 4) were used. The Na/K-ATPase activity was determined after thawing, whereas sperm kinematics, membrane integrity, and expression of Na/K-ATPase on sperm surface were evaluated immediately post-thaw and after 120 minutes of incubation. Within the same incubation time, there was no difference on sperm membrane integrity, kinematics, and the expression of Na/K-ATPase on the sperm surface between HF and LF bulls. Kinematic parameters of LIN and VCL were not influenced by incubation time in samples from HF and LF, respectively. A tendency (P = 0.06) of higher Na/K-ATPase enzymatic activity for sperm of HF bulls compared to LF bulls was observed (0.49 ± 0.07 and 0.32 ± 0.06, respectively). In conclusion, Na/K-ATPase activity and expression in thawed sperm from Angus bulls are not related to the fertility index after fixed-time artificial insemination. However, sperm kinematics related to hyperactivation might indicate higher sperm cryotolerance for HF bulls.

Resumo em Inglês:

Abstract This study establishes the serological frequency against Neospora caninum on day zero and the presence of N. caninum DNA surveyed throughout the gestation of Bubalus bubalis females in a bovine buffalo system in the central zone of the state of Veracruz, Mexico. Blood samples were taken from 11 females in 6 different sampling periods and analyzed for N. caninum antibodies detection on day zero. DNA detection by PCR was performed on all sampling periods. The gestation months of the females were recorded for five trimesters by ultrasonography, as well as births and pregnancy losses. Recorded seropositivity and positivity for agent DNA were 90.9% (95% CI 58.7-9.7) and 36.3% (95% CI 10.9-69.2), respectively, on day zero. N. caninum DNA was detected between 18.1% (95% CI 2.3-51.7) and 45.4% (95% CI 16.7-76.6) over the five trimesters of observation, with three births and three abortions recorded. The studied water buffalo population had a high presence of N. caninum antibodies; however, the detection of N. caninum DNA remained below 47% in the females. The association was only observed in the detection of DNA with pregnant females (P 0.007). Our results support the hypothesis of the resistance of water buffaloes to infection and the onset of clinical signs against infection by N. caninum even upon a high possibility of infection and reinfection described in this production system in Mexico.

Resumo em Inglês:

Abstract GnRH analogues were widely used for controlld ovary stimulation, but their effects on oocyte quality remain contradictory. This study aimed to explore the influence of GnRH analogues on oocyte quality in mice. A total of 120 mice were randomly assigned to four groups:(i)GnRH-a+PMSG group; (ii) GnRH-ant+PMSG group; (iii) PMSG group; (iv) Control group. Ovaries were collected for quantitative real-time polymerase chain reaction (qRT-PCR) to assess GDF9 and BMP15 mRNA expression, and protein expression were evaluated by western blotting. Moreover, embryo developmental progress in vitro and implantation rate in vivo were recorded. Compared with control group, both GDF9 mRNA and protein expressions were strengthened in PMSG group, but reduced in the presence of GnRH-a or GnRH-ant. The GnRH-a group exhibited decreased BMP15 mRNA expression compared to PMSG group, while the GnRH-ant group did not show the same pattern. BMP15 protein expression were not statisticlly different among the four groups. Notably, there was no statistically difference in the expression of these two factors between GnRH-a and GnRH-ant groups. The percentage of zygotes progressing to the 2-cell stage and percentage of 2-cell advancing to the blastocyst stage were similar in the PMSG group and control group. However, both the GnRH-a and GnRH-ant groups showed decreased embryos development rates compared to other two groups. The embryonic implantation rate in control group (53.3%) was higher than that in the GnRH-a and GnRH-ant groups (33.3% and 30.8%, P<0.05). The difference between the PMSG (45.0%) and GnRHa group was statistically significant (P value of 0.023), but not between the PMSG and GnRH-ant group (P value of 0.486). No statistical difference was confirmed between GnRH-a and GnRH-ant groups. Our findings shed light on the safety of GnRH analogues in ovary stimulation, and highlight the need for further research to establish optimal and effective controlled ovary stimulation protocol.

Resumo em Inglês:

Abstract Letrozole comprises a non-steroid aromatase inhibitor that has been applied as a preventive for many uses, such as breast cancer prevention, treatment of hormonal dysfunction, and male infertility. Precisely in Northeast Brazil, ovine consist of the leading livestock produced, and their reproduction in captivity has been demonstrated difficult. Thus, we hypothesized whether the application of letrozole will improve male sheep reproduction. One group of 6 animals received a daily dosage of 0.5mg/Kg of letrozole for 60 days, while the other six animals were used as control. Samples were collected from control and treated animals after 30 and 60 days of the experiment. Blood samples were collected to measure the steroid hormone levels. Semen was collected from control and treated groups using an artificial vagina and cryopreserved for spermatozoa morphology and CASA analysis. The testicles were collected for histological analysis, gene expression, and immunohistochemistry of P450aromatase protein. Hormone levels demonstrate no differences in the estradiol/testosterone levels among the control and both treated groups. Immunohistochemistry analysis revealed the presence of P450aromatase protein in spermatogonia cells and Leydig cells in the control and treated groups in both periods analyzed. Moreover, there were no differences in the P450aromase gene expression in the control and treated group. Morphological analysis of the spermatozoa revealed that letrozole treatment did not affect mitochondrial activity or cause any deformities. In addition, motility parameters in the sperm from the treated group were not affected by letrozole treatment compared to the control group. Morphological analysis of the testis demonstrated that letrozole treatment increase the seminiferous tubule area but no signs of germ cell damage. Our results show that letrozole has a morphological effect on the testicles in the ovine model but no pathological or severe effect caused by hormone level imbalance. Overall, letrozole comprises a non-steroid aromatase inhibitor, which can be applied to ovine reproduction.

Resumo em Inglês:

Abstract This study aimed to investigate the effect of a short glutamate supply on the ovarian response in goats with low body condition scores. Twenty-one goats had their estrus and follicular waves synchronized using three injections of prostaglandin analog at seven-day intervals. Goats were allocated to groups receiving 10 mg/kg LW (iv) of glutamate administered in a single dose (group LBCG1, n = 7) or in two doses five days apart (group LBCG2, n = 7). The control group (LBC; n = 7) received saline solution. Glutamate treatment did not affect glucose, cholesterol, or glutathione peroxidase levels, body weight, or adipose deposits. During the experimental period, the LBCG2 group showed a higher (P < 0.05) number of follicles (> 3 mm) and an increase in follicle diameter (P < 0.05). Glutamate supply improved (P < 0.05) the intraovarian Doppler blood area size in the LBCG groups, and the second dose in LBCG2 also induced a higher (P < 0.05) systolic and diastolic peak of the ovary artery. After ovulation induction, LBCG2 exhibited a high (P < 0.05) volume of the corpus luteum and vascularized area. We concluded that the supply of two doses of glutamate five days apart was efficient in ovarian stimulation in goats with a low body condition.

Resumo em Inglês:

Abstract The Brazilian Buriti oil presents low extraction costs and relevant antioxidant properties. Thus, this work aimed to analyze Buriti oil biomaterial (BB), within its physicochemical properties, biocompatibility and cellular integration, with the purpose to the use as a growth matrix for Goat Wharton’s jelly mesenchymal stem cells. Biomaterials were produced from Buriti oil polymer (Mauritia flexuosa), for it’s characterization were performed Infrared Region Spectroscopy (FTIR) and Thermogravimetric Analysis (TG and DTG). The biointegration was analyzed by Scanning Electron Microscopy (SEM) and histological techniques. In order to investigate biocompatibility, MTT (3-(4,5-dimetil-2-tiazolil)-2,5-difenil-2H-tetrazólio) test and hemolytic activity tests were performed. The activation capacity of immune system cellswas measured by phagocytic capacity assay and nitric oxide synthesis . The BB presented an amorphous composition, with high thermal stability and high water expansion capacity, a surface with micro and macropores, and good adhesion of Wharton’s jelly mesenchymal stem cells (MSCWJ). We verified the absence of cytotoxicity and hemolytic activity, in addition, BB did not stimulate the activation of macrophages. Proving to be a safe material for direct cultivation and also for manufacturing of compounds used for in vivo applications.

Resumo em Inglês:

Abstract The risk of pregnancy loss in mares leads to the use of exogenous hormones to help pregnancy maintenance. The objective was to evaluate the proportion of thyroid hormones and steroids in neonates, in the following postpartum period, born to mares fed with synthetic progesterone and to verify the existence of a correlation between the level of progesterone between mother and neonate. Twenty-seven mares and their foals were used. The animals were divided into 5 experimental groups: group 1 (control, without hormonal supplementation), group 2 (random samples fed to 120 days of pregnancy with long-term progesterone), group 3 (mares fed with short-term progesterone as of 280.º day of pregnancy), group 4 (mares fed with long-term progesterone as of 280.º day of pregnancy) and group 5 (mares fed with synthetic hormone [altrenogest] as of 280.º day of pregnancy). The animal’s blood collection took place immediately after parturition for the hormonal measurement. The hormones measured in neonates were total T3, free T4, TSH, progesterone and cortisone. In mares, only levels of progesterone. The groups of neonates showed no difference on levels of total T3, free T4, TSH and progesterone. There was no difference on levels of progesterone in mares among the groups. Neonates from groups 4 and 5 had higher and lower cortisone levels, respectively. No neonate showed clinical change. There was also no correlation between levels of progesterone in mares and foals. Thus, hormonal supplementation with long-term progesterone as of 280 days of pregnancy leds to an increase in the neonate's cortisone levels, in the meantime, supplementation with altrenogest as of 280 days of pregnancy caused a decrease on cortisone levels in foals, despite clinical signs have not been observed on these animals.

Resumo em Inglês:

Abstract Sperm motility and kinematics analysis are important to predict bull fertility. However, there are other molecules in the sperm with the ability to improve the pregnancy rate. For example, PLCZ1 is a sperm protein that plays a unique role in the activation of the zygote and is important for the survival of the embryo. The objective of this work was to compare the expression of PLCZ1 mRNA in sperm cells of Chihuahuan Criollo and European bulls in the winter and summer seasons, under a low-input system. Six (3.33 ± 0.43 years old) bulls (three Criollo, three European) were used. Gross and individual motility were measured in semen obtained by electrostimulation. The cell pack was pelletized by centrifugation and stored in liquid nitrogen. The sperm cells were purified and total RNA was extracted. cDNA was synthesized to perform qPCR and measure the relative level of PLCZ1 transcripts in each bull. There were no differences in individual motility, however, gross motility was lower (P < 0.05) in Criollo bulls, both in the winter (71.1 ± 2.8 vs. 76.6 ± 2.8%) and in the summer season (58.9 ± 2.8 vs. 77.7 ± 2.8%). PLCZ1 expression was 5.3 times higher (P < 0.05) in winter than in summer (5.09 ± 1.09 vs 0.959 ± 1.09). No difference (P>0.05) was found in the expression levels of PLCZ1 between both breeds (4.36 ± 1.09 vs 1.69 ± 1.09), for Criollo and European, respectively. Although the animals presented seminal motility within the recommended limits for insemination, the expression levels of PLCZ1 vary depending on the time of the year and this might impact the rate of successful pregnancies. Therefore, it is important to complement conventional analysis of seminal quality with molecular characteristics.

Resumo em Inglês:

Abstract The objectives of the study were to (1) describe the kinematic parameters of spermatozoa (2) compare methods of evaluating sperm viability (3) validate assays of functionality and integrity of the sperm membrane and (4) evaluate possible changes between spermatozoa from the epididymis and the vas deferens of the greater rhea. Semen samples were recovered from 7 adult individuals. Sperm motility was characterized by adjusting the set-up for Computer-assisted semen analysis (CASA) to that new species. For sperm viability evaluation, smears of bromophenol blue and eosin-nigrosine dyes were used. Five solutions of different osmolarities were then tested for the hypoosmotic swelling test (HOST). The combination of fluorescent probes (propidium iodide - IP and Hoechst 33342) was also used to assess plasma membrane integrity. Data were presented as mean ± SEM. Rhea spermatozoa from the vas deferens had an overall motility of 14.6 ± 2.5%. The bromophenol blue staining technique revealed that 64.6 ± 5.2% sperm were viable, while that proportion was 72.1 ± 2.5% using eosin-nigrosine. An average of 77.6 ± 4.8% of spermatozoa reacted to the HOST with distilled water at 0 mOsm/l. Fluorescent probes indicated that 65.3 ± 2.6% of spermatozoa had intact membranes. Interestingly, no statistical differences were observed between the parameters analyzed in the epididymal spermatozoa and the vas deferens. These new assays set reference values that can now be used to further exploration of sperm handling conditions and freezing protocols in rheas.

Resumo em Inglês:

Abstract Semen collection methods vary greatly and rely on the practitioner's expertise, available materials, and the specific behavioral traits of the male animals involved. When it comes to domestic cats, wild felids, and canids, semen collection is particularly challenging. Thus, given the difficulty of semen collection in these species, pharmacological semen collection (PSC) stands out since it is a quick and straightforward method that does not require specific equipment. The PSC consists of administering α2-adrenergic receptor agonist drugs, mainly medetomidine, and dexmedetomidine, aiming semen release into the urethra with posterior urethral catheterization and sperm recovery. This technique was primarily described in domestic cats and wild felids, and despite the decreased seminal volume, the retrieved semen is highly concentrated and presents good quality. However, further studies are required to optimize semen collection in domestic dogs and wild canids. Therefore, the purpose of this review is to provide a comprehensive overview of the research developed on pharmacological semen collection (PSC) in the past few decades. The objective is to equip professionals with the essential knowledge required for the efficient application of this technique in both domestic and wild canids and felids and to make a valuable contribution to conservation efforts and the preservation of biodiversity, aligning with the principles of One Conservation.

Resumo em Inglês:

Abstract The in situ population of jaguars in the Caatinga is less than 250 individuals, subdivided into five subpopulations, and is classified as endangered regarding its risk of extinction. Luisa, a 15-year-old female weighing 36 kg, was the last known ex situ jaguar from this biome. Her reproductive evaluation is detailed in this manuscript. Luisa was subjected to both a clinical and laparoscopic evaluation of her reproductive system. After 45 days of reproductive investigation, she died unexpectedly, and skin fragments were taken to establish the postmortem fibroblast lineage. At the clinical evaluation, Luisa had small, undeveloped mammary gland and a small vulva, characteristic of a nulliparous female, with no mammary gland nodules, edema, or abnormal masses. By laparoscopy, normal-appearing bladder and bowel loops were observed, as were uterine horns with standard color, shape, and length with no striae. Ovaries and uterine horns seem free of fibrinous adhesions. Both ovaries showed a yellowish color, a fibrous consistency, a decreased size (atrophied), and no follicles, hemorrhagic corpus, corpus luteum, luteal scars, or other abnormal structures. We may assume that this jaguar female was infertile based on Luisa's mature age and the absence of birthing or ovarian activity signs. The harsh conditions of the Caatinga biome, which included low food availability and frequent conflicts with humans, may have impacted both the pregnancy and lactation of Luisa’s mother and her development after birth.