Insights into alternative cryoprotectants to freeze sperm of domestic cats.

Globalization and habitat destruction pose a significant threat to wildlife felids. Even though conservation banks for genetic materials have been created, the sperm cryopreservation with minimal cell damage is still a great challenge. Thus, this study aimed to compare the effects of two commercial extenders with different concentrations of alternative cryoprotectants on thawed sperm quality of domestic cats. Five adult cats were anaesthetized (using a combination of 40 µg/kg medetomidine associated to 5 mg/kg ketamine), and the semen was collected by electroejaculation (electrical stimulation of 2-3 V). Semen samples were evaluated for sperm characteristics (kinetics, morphology, membrane integrity and morphometry). Subsequently, they were sorted into two aliquots and centrifuged. The aliquots were added to a commercial extender containing 3% glycerol and 2% methylformamide (extender I) or 2% glycerol and 3% methylformamide (extender II), frozen, thawed (37°C/30 s) and reevaluated. Comparatively, the sperm kinetics and membrane integrity of fresh semen were higher (p < .002) than frozen samples in extender I and II. Total and progressive motility were lowest in the thawed samples. However, the subjective analysis indicated high sperm motility, since the kinetics evaluation was impaired by the low cell number in the thawed samples. There were no differences in sperm morphology between the groups. In the sperm morphometric analysis, a significant difference (p = .04) was identified in the length of the intermediate piece in extender II samples compared with fresh and extender I. Thus, it can be concluded that although the concentrations tested did not maintain the kinetic parameters and membrane integrity of spermatozoa after thawing, the extender with a lower concentration of glycerol was less toxic for maintaining the midpiece length.

Renal biomarkers, clinical parameters, and renal Doppler velocimetry in bitches with cystic endometrial hyperplasia-pyometra complex.

Cystic endometrial hyperplasia (CEH)-pyometra complex is the most common uterine infection in adult and elderly bitches and can cause renal dysfunction. The aim of this study was to measure and compare urinary creatinine, urea, symmetric dimethylarginine (SDMA), urinary protein-creatinine ratio (UPC), measurement of systolic blood pressure (SBP), and Doppler velocimetry of renal arteries in patients with CEH-pyometra complex before and after an average of 6 months of treatment, evaluating the possibility of the changes persisting. The evaluation was conducted at two moments: M1 (at the diagnosis of CEH-pyometra, n = 36) and M2 (after an average of six months of treatment, n = 16). For the control group, eight bitches with no changes in blood tests or history of conditions underwent Doppler ultrasound evaluation of the renal arteries. At both M1 and M2, we measured creatinine, urea, and serum SDMA, UPC, SBP, and Doppler ultrasound of the renal arteries. Patients were evaluated according to the following groups: azotemic (AZO) and non-azotemic (NAZO), and open and closed cervix pyometra. The parameters were compared between animals present in both moments presented as M1R (bitches that were in M1 and M2) and M2. Statistical significance was considered when p < .05. The medians found for creatinine in M1 were as follows: 1.15 mg/dL, being 1.8 mg/dL for AZO (12/36) and 0.95 mg/dL for NAZO (24/36); and in M2: 0.85 mg/dL (16/16), being 1.15 mg/dL for AZO (4/16) and 0.8 mg/dL for NAZO (12/36). For urea, in M1 it was 36 mg/dL (32/36), with AZO being 103 mg/dL (11/32) and 33 mg/dL in NAZO (21/32); and in M2 32 mg/dL (16/ 16), being 29 mg/dL for AZO (4/36), and 31 mg/dL for NAZO (3/15). The median SDMA measured in M1R was 17 µg/dL (15/16), with AZO being 31 µg/dL (3/15), and NAZO being 16.5 µg/dL (12/15); and in M2, SDMA was 12 µg/dL (16/16), with AZO being 12.5 µg/dL (4/16), and NAZO being 12 µg/dL (12/16). The median UPC measured in M1 was 1.15 (10/36), with AZO being 0.25 (1/10), and NAZO being 1.38 (9/10); and in M2, it was 0.2 (13/16), being 0.1 in AZO (4/13), and 0.2 (9/16) in NAZO. For SBP, in M1, it was 118 mmHg (30/36), with AZO being 102 mmHg (10/30) and 133 mmHg in NAZO (20/30); and in M2 142.5 mmHg (12/16), being 155 mmHg for AZO (4/12), and 140 mg/dL for NAZO (8/12). When comparing animals with open and closed cervixes, a difference was found between SDMA measurements (p = .001). There was a distinction between PI and RI of the left and right kidneys consecutively (p = .007; p = .033; p = .019; p = .041). Correlations found in M1: SDMA × PI RIM DIR (r = 0.873; p = .002), SDMA × PSV RIM ESQ (r = 0.840; p = .004), SDMA × EDV RIM ESQ (r = 0.675; p = .046). With this study, we conclude a return to normality of renal biomarkers and clinical parameters after six months. Yet, there is a persistence of Doppler velocimetric measurements between the two moments. Thus, this parameter is not suitable for identifying and classifying chronic kidney injury in bitches with pyometra.

Comparison of two pharmacological semen collection times with α2-adrenergic agonist in domestic cats.

The use of α2-adrenergic agonists in association with urethral catheterization has been used as a technique for pharmacological semen collection in cats. The mechanism of action of this drug is the stimulation of adrenoreceptors in the vas deferens, which results in ejaculation. While medetomidine is the α2-agonist most commonly used in studies, ejaculation with the use of dexmedetomidine associated with ketamine has been effective, but with variable results. Therefore, further studies regarding the methodology of use are required to obtain better seminal quality. This study aimed to compare two pharmacological semen collection times after the association of dexmedetomidine (30 µg/kg, IM; Dormitor®, Zoetis), ketamine (5 mg/kg, IM; ketamine, Vetnil) and urethral catheterization using a tomcat probe (0.8 mm × 1.00 mm × 11 cm). The collections were divided into two experimental groups: G10 (N = 8; urethral catheterization after 10 min of anaesthesia) and G15 (N = 8; urethral catheterization after 15 min of anaesthesia). The ejaculates were evaluated for ejaculate volume, sperm concentration, morphology and kinetics using the CASA system. To compare the groups, the t-test and the Mann-Whitney U-test were used with a significance level of 5%. It was identified that ejaculate volume (G10: 22.62 ± 2.13 vs. G15: 26.81 ± 1.55; p < .001) and sperm concentration (G10: 48.10 × 106 ± 17.84 vs. G15: 90.18 × 106 ± 19.35; p < .001) was higher in G15 than in G10 and had a lower percentage of minor defects than G10 (G10: 3.12 ± 2.41 vs. G15: 1.00 ± 1.19; p = .043). Regarding the kinetic parameters, the results of G15 were better for total motility-TM (G10: 67.00 ± 10.33 vs. G15: 81.87 ± 7.99; p = .006) and faster cells-RAPID: (G10: 55.00 ± 16.63 vs. G15: 74.25 ± 11.94; p = .019); whereas a higher proportion of cells with slow speed-SLOW were seen in G10 (G10: 31.00 ± 12.07 vs. 17.12 ± 7.53; p = .015). Based on these findings, we suggest that collection via urethral catheterization should be performed 15 min after the application of ketamine-associated dexmedetomidine to obtain a better-quality ejaculate.

Fecal microbiota profile of ovariohysterectomized cats submitted to estrogen replacement / Perfil da microbiota fecal de gatas ovariohisterectomizadas submetidas à reposição estrogênica

This study aimed to observe the effects of 17 ß-estradiol replacements on the fecal microbiota in spayed cats. Individual samples of fresh feces were collected and stored at -80° C. Sequencing of the V3/V4 regions of the 16S rRNA gene was used, and bioinformatic analysis was performed. Firmicutes/Bacteriodetes ratio was lower in the group receiving estrogen replacement compared to the SHAM group (P = 0,005). Jaccard index (P = 0.123) and Yue & Clayton index (P = 0.094) did not reveal alpha and beta diversity differences. The linear discriminant analysis effect size (LefSe) identified Firmicutes and MegasPhaera as the biomarkers for the SHAM group, and Burkholderiales, Betaproteobacteria, Sutterellaceae, Suterella, Proteobacteria, Proteobacteria unclassified and Collinsella for the group receiving estrogen replacement.(AU)

O objetivo deste estudo foi observar os efeitos da reposição de 17 ß-estradiol na microbiota fecal de gatas castradas. Amostras individuais de fezes frescas foram colhidas e armazenadas a -80°C. Foi realizado o sequenciamento das regiões V3/V4 do gene 16S rRNA e a análise bioinformática. A razão Firmicutes/Bacteriodetes foi menor no grupo que recebeu reposição estrogênica em comparação ao grupo SHAM (P = 0,005). O índice de Jaccard (P = 0,123) e o índice de Yue & Clayton (P = 0,094) não revelaram diferenças na alfa e beta diversidade. A análise discriminatória linear de tamanho do efeito (LefSe) identificou Firmicutes e Megasphaera como biomarcadores para o grupo SHAM, e Burkholderiales, Betaproteobacteria, Sutterellaceae, Suterella, Proteobacteria, Proteobacteria não classificada e Collinsella para o grupo que recebeu reposição estrogênica.(AU)

The proAKAP4 concentrations in Nelore bull sperm and their relation to FTAI conception rate results.

The AKAP4 protein has an essential role in sperm motility, and its precursor, the proAKAP4, is considered a biomarker for sperm quality and fertility. Despite this, proAKAP4 concentration was never evaluated in Bos indicus sperm. Therefore, this study aims to determine the proAKAP4 concentration in the sperm of Nellore bulls and its association with sperm kinetics, morpho-functionality, morphology, and conception rates after fixed-time artificial insemination (FTAI). The bulls (n = 9) used in our study presented sperm characteristics above expected standards for quality. Sperm from each bull was evaluated regarding kinetics by the CASA system, and assessed for mitochondrial functionality, sperm membrane integrity, and morphology. For the FTAI protocol, multiparous Nelore cows (n = 1507) were inseminated with frozen-thawed sperm from the same batches used in the laboratory analysis. Additionally, the sperm proAKAP4 concentration was determined using an ELISA kit. The data were analyzed by linear regression and the significance level was set to 5%. The mean conception rate was 52.52%. The mean proAKAP4 concentration was 25.75 ng/106 spermatozoa. The proAKAP4 concentration positively affected the sperm total and progressive motilities, and conception rates after FTAI (respectively, r2 = 0.49, P = 0.03; r2 = 0.63, P = 0.01; and r2 = 0.51, P = 0.03). Based on the relationship detected in this study, we conclude that the sperm proAKAP4 concentration is a suitable biomarker to predict the quality and fertility of frozen-thawed Bos indicus semen.

Biotecnologias na preservação de espermatozoides felinos / Biotechnologies in the preservation of feline sperm

O gato doméstico é a única espécie da família Felídea sem risco ou iminência de extinção, diferente da maior parte dos felinos selvagens. Desta forma, o desenvolvimento e aprimoramento de diferentes biotécnicas reprodutivas, são essenciais para a manutenção da qualidade reprodutiva, tendo em vista a preservação de espécies mais vulneráveis. Além disso, as biotécnicas do sêmen são para as tecnologias reprodutivas, como a inseminação artificial (IA) e a fertilização in vitro (FIV). Sendo assim, o objetivo deste compilado bibliográfico foi abordar as principais técnicas de colheita, análise e preservação de sêmen/espermatozoides felino, assim como o uso dessas células em IA e FIV. Para a colheita do sêmen felino, diferentes métodos têm sido aplicados: ejaculação farmacológica, eletroejaculação e vagina artificial. Em caso de óbito do reprodutor, os espermatozoides recuperados do epidídimo também apresentam viabilidade reprodutiva. Ademais, a cinética espermática avaliada pelo sistema CASA, a morfologia e a morfometria são as principais análises que demonstram a qualidade espermática e refletem na fertilidade do ejaculado. O sistema CASA também avalia a trajetória individual de cada espermatozoide, que ao se agrupar em clusters, demonstra a heterogeneidade do ejaculado nas subpopulações. Contudo, os diluentes para a conservação e refrigeração dos espermatozoides felinos e as curvas de congelação ainda não estão totalmente estabelecidos e influenciam diretamente a viabilidade dos espermatozoides criopreservados. Diante disso, os resultados da utilização do sêmen felino após criopreservação são inconsistentes, sendo necessários mais estudos para elucidar melhores curvas de congelação e meios de diluentes para viabilizar a preservação do material genético dos gatos.

The domestic cat is the only species of the Felidea family without risk or imminence of extinction, unlike most wild cats. Therefore, the development and improvement of different reproductive biotechnologies are essential for the maintenance of reproductive quality for the preservation of the most vulnerable species. Furthermore, semen biotechnologies are the basis for reproductive technologies such as artificial insemination (AI) and in vitro fertilization (IVF). Thus, the objective of this bibliographic compilation was to approach the main techniques of collection, analysis, and preservation of feline semen/sperm, as well as the use of these cells in AI and IVF. For feline semen collection, different methods have been applied: pharmacological ejaculation, electroejaculation, and artificial vagina. In case of death of the sire, sperm recovered from the epididymis also show reproductive viability. Moreover, the sperm kinetics evaluated by the CASA system, the morphology, and the morphometry are the main analyzes that demonstrate sperm quality and reflect on ejaculate fertility. The CASA system also evaluates the individual path of each sperm, which, when grouped into clusters, demonstrates the heterogeneity of the ejaculate in the subpopulations. However, diluents for the conservation and refrigeration of feline sperm and freezing curves are not yet fully established and directly influence the viability of cryopreserved sperm. Therefore, the results of using feline semen after cryopreservation are inconsistent, and further studies are needed to elucidate better freezing curves and diluents to enable the preservation of the genetic material of cats.

Sperm subpopulations influence the pregnancy rates in cattle.

This study aimed to study the characteristics and subpopulations of spermatozoa from bulls with low and high reproductive performance based on pregnancy rates. Based on historical records of pregnancy rate from four farms, 24 bulls were selected. Two groups were established, with low pregnancy rates (n = 12; LOW), including bulls that presented pregnancy rates <52.27% (33.33% to 51.81%); and a group with high pregnancy rates (n = 12; HIGH), with pregnancy rates >52.27% (52.27% to 69.64%), after fixed-time artificial insemination (FTAI). The thawed sperm straws were analysed to sperm kinetics, morphology, plasma membrane integrity and sperm subpopulations. The LOW group exhibited a higher proportion of static cells (p < .05). In contrast, the HIGH group showed greater percentages for membrane integrity and total and progressive motility, and cells with fast and medium velocity (p < .05). In the cluster procedures, four sperm subpopulations were established. The low-fertility bulls presented the highest percentage of subpopulation 2 (41.46%), characterized by slow and progressive spermatozoa. The high-fertility bulls exhibited the highest percentage of subpopulation 3 (37.17%), characterized by fast and nonlinear spermatozoa. Results from this study indicated that bulls with greater percentages of fast and nonlinear spermatozoa seem to have greater fertilization capacity and the subpopulations analysis can be considered a tool to identify ejaculates with high fertility.

Sperm filtration as an alternative technique for seminal plasma separation in boars / Filtração de ejaculados suínos como alternativa para a separação do plasma seminal

The present study aimed to evaluate the filtration for separating seminal plasma of boars' ejaculate by means of sperm viability and the occurrence of hyperactivation and lipid peroxidation in fresh semen and after cooling for up to 96 hours. The ejaculate of eight healthy boars of different breeds was collected and the gelatinous portion was separated and discarded. In the laboratory, the semen was fractioned into three aliquots (groups G1, G2 and G3) as follows: G1: semen with plasma diluted in BTS (TOTAL BTS); G2: semen centrifuged at 600G/10' (BTS CEN); and G3: semen filtered with the Sperm-filter® following dilution of the retained cells with BTS (BTS FIL). The analyses were performed at three moments: with fresh samples (D0) and after 48 (D2) and 96 hours (D4) of cooling at 17ºC. The kinetic evaluation was performed using the CASA system, which provided data for the classification of sperm hyperactivity. For lipid stress analysis, the TBARS (thiobarbituric acid reactive substance) test was performed. The variance analysis test was conducted to compare the results between the groups and moments analyzed. The results showed better total motility values (%) for G1 at D0 (67.9, P= 0.001), D2 (36.6, P= 0.004) and D4 (26.1, P= 0.003). The occurrence of hyperactivity was observed in G2 and G3 at moments D2 and D4. In addition, TBARS showed higher peroxidation levels for G1 at D0 (8.1 mM MDA/ml, P= 0.01), D2 (7.4 mM MDA/ml, P= 0.02), and D4 (6.41mMol MDA/ml, P= 0.008) when compared to G2 and G3. Since the filtration method did not demonstrate any damage to the sperm viability, the study concluded that sperm filtration is an accessible and valid tool to replace centrifugation.(AU)

O presente estudo objetivou avaliar a filtração como alternativa para a separação do plasma seminal de ejaculados suínos, ao considerar a viabilidade espermática por meio da ocorrência de hiperativação e peroxidação lipídica no sêmen fresco e após refrigeração por até 96 horas. O ejaculado, de oito cachaços saudáveis de diferentes raças, foram colhidos por meio da técnica da mão enluvada e porção gelatinosa foi separada e descartada. Em laboratório, o sêmen foi fracionado em três alíquotas (grupos G1, G2 e G3) da seguinte forma: G1: sêmen e plasma seminal, diluído em BTS (TOTAL BTS); G2: ejaculado centrifugado a 600G/10' para separação do plasma seminal, e o pellet de espermatozoides formados foram ressuspensos em BTS (BTS CEN); e G3: sêmen filtrado com Sperm-filter®, e espermatozoides retidos foram diluídos em BTS (BTS FIL). As análises foram realizadas em três momentos: amostras frescas (D0), após 48 horas (D2) e seguidas 96 horas (D4) de refrigeração a 17ºC. A avaliação cinética foi realizada pelo sistema CASA, que forneceu dados para a classificação da hiperatividade espermática. Para análise de estresse lipídico, foi realizado o teste TBARS (substâncias reagente ao ácido barbitúrico). Um teste de análise de variâncias foi feito para detectar diferenças entre os grupos e momentos avaliados. Os resultados mostraram melhores valores de motilidade total (%) para G1 em D0 (67,9, P = 0,001), D2 (36,6, P = 0,004) e D4 (26,1, P = 0,003). A ocorrência de hiperatividade foi observada em G2 e G3 nos momentos D2 e D4. Além disso, o TBARS mostrou níveis de peroxidação lipídica mais elevados para G1 em D0 (8,1 mM MDA / ml, P = 0,01), D2 (7,4 mM MDA/ml, P = 0,02) e D4 (6,41 mMol MDA / ml, P = 0,008) quando comparado com G2 e G3. Como a filtração não induziu a danos na viabilidade espermática, o estudo concluiu que a filtração espermática é uma ferramenta acessível e válida para substituir a centrifugação com intuito de separar o plasma seminal.(AU)

Influência da cinética espermática sobre a taxa de prenhez na inseminação artificial em tempo fixo em bovinos / Influence of sperm kinetics on pregnancy rate in fixed-time artificial inseminations in cattle

The aim of the study was to evaluate the influence of hyperactivated sperm kinetics on pregnancy rate in IATF. Two experimental groups were established, based on the results of the semen analysis in the CASA system: groups of bulls with hyperactivated sperm (N = 10; HIPER) and bulls with non-hyperactivated sperm (N = 14; N HIPER). Differences between groups were estimated by the t test, and a significance level <5% was considered. Highervalues for the variables were identified in the HIPER group: VAP; VSL; VCL; ALH; RAPID cells and SLOW cells. On the other hand: BCF; STR; LIN; WOB and MEDIUM cells, which had higher values in the N HIPER group. No difference was found for the pregnancy rate variable between groups (p=0.454). Therefore, although the CASA system is an objective method of analysis, we can consider that it alone is not sufficient to predict seminal fertility, but when associated with other techniques such as: specific software and multivariate statistics that identify subpopulations, if makes it an important methodology for assessing semen quality.

Características do comportamento hiperativado de espermatozoides de felinos domésticos / Characteristics of the cat sperm hyperactivated behavior

Sperm hyperactivity is a physiological behavior, and in the feline species it is characterized by an increase in the curvilinear velocity (VCL) and a greater head beat (ALH) evaluated by the CASA system. The study aimed to compare and correlate kinetic parameters of Hyperactive and Non-Hyperactive feline ejaculates when considering the means of VCL and ALH. Ejaculates were collected by electro ejaculation from 21 cats. The seminal samples had the kinetic parameters evaluated by the CASA system. From the average values of VCL and ALH, the ejaculates were classified in group HP (Hyperactivated, when VCL>190.17µm/s and ALH>6.44µm) and NHP (Non-Hyperactivated, when VCL<190.17 and ALH<6.44 µm). A T test and Pearson's correlation were performed with a significance of p<0.05. Among the groups, were detected higher values of total (HP: 68,2% vs NHP: 35,9%) and progressive (HP:40,1% vs NPH: 17,18%) motility, VAP (HP: 165,85µm/s vs NHP: 97,72 µm/s), VSL (HP:137,63µm/s vs NHP 82,6µm/s), VCL (HP: 237,31µm/s vs NHP: 147,94µm/s) and ALH (HP: 7,28µm vs NHP:5,42µm) for the HP group. There was a correlation in the HP ejaculates between total and progressive motility. In the NHP group, a correlation was observed between motility and progressive motility, and between progressive motility and STR and LIN. It was concluded that HP spermatozoa have a higher curvilinear speed, while NHP spermatozoa stand out due to their straight path.

Influência da cinética espermática sobre a taxa de prenhez na inseminação artificial em tempo fixo em bovinos / Influence of sperm kinetics on pregnancy rate in fixed-time artificial inseminations in cattle

The aim of the study was to evaluate the influence of hyperactivated sperm kinetics on pregnancy rate in IATF. Two experimental groups were established, based on the results of the semen analysis in the CASA system: groups of bulls with hyperactivated sperm (N = 10; HIPER) and bulls with non-hyperactivated sperm (N = 14; N HIPER). Differences between groups were estimated by the t test, and a significance level <5% was considered. Highervalues for the variables were identified in the HIPER group: VAP; VSL; VCL; ALH; RAPID cells and SLOW cells. On the other hand: BCF; STR; LIN; WOB and MEDIUM cells, which had higher values in the N HIPER group. No difference was found for the pregnancy rate variable between groups (p=0.454). Therefore, although the CASA system is an objective method of analysis, we can consider that it alone is not sufficient to predict seminal fertility, but when associated with other techniques such as: specific software and multivariate statistics that identify subpopulations, if makes it an important methodology for assessing semen quality.(AU)

Características do comportamento hiperativado de espermatozoides de felinos domésticos / Characteristics of the cat sperm hyperactivated behavior

Sperm hyperactivity is a physiological behavior, and in the feline species it is characterized by an increase in the curvilinear velocity (VCL) and a greater head beat (ALH) evaluated by the CASA system. The study aimed to compare and correlate kinetic parameters of Hyperactive and Non-Hyperactive feline ejaculates when considering the means of VCL and ALH. Ejaculates were collected by electro ejaculation from 21 cats. The seminal samples had the kinetic parameters evaluated by the CASA system. From the average values of VCL and ALH, the ejaculates were classified in group HP (Hyperactivated, when VCL>190.17µm/s and ALH>6.44µm) and NHP (Non-Hyperactivated, when VCL<190.17 and ALH<6.44 µm). A T test and Pearson's correlation were performed with a significance of p<0.05. Among the groups, were detected higher values of total (HP: 68,2% vs NHP: 35,9%) and progressive (HP:40,1% vs NPH: 17,18%) motility, VAP (HP: 165,85µm/s vs NHP: 97,72 µm/s), VSL (HP:137,63µm/s vs NHP 82,6µm/s), VCL (HP: 237,31µm/s vs NHP: 147,94µm/s) and ALH (HP: 7,28µm vs NHP:5,42µm) for the HP group. There was a correlation in the HP ejaculates between total and progressive motility. In the NHP group, a correlation was observed between motility and progressive motility, and between progressive motility and STR and LIN. It was concluded that HP spermatozoa have a higher curvilinear speed, while NHP spermatozoa stand out due to their straight path.(AU)