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Integridade cromatínica e morfometria das cabeças espermáticas e suas relações com a concepção em éguas

Wed, 25 Feb 2026 00:00:00 GMT

Title: Integridade cromatínica e morfometria das cabeças espermáticas e suas relações com a concepção em éguas Abstract: The evaluation of sperm chromatin and morphometry has gained relevance for diagnosing subfertility in stallions, especially when conventional seminal parameters do not explain reproductive failures. This study investigated whether changes in chromatin compaction, detected by Toluidine Blue, Feulgen Reaction, and Acridine Orange, as well as computational sperm head morphometric variables, correlate with conception in mares inseminated with fresh or cooled semen. Additionally, sperm morphometry was compared between Quarter Horse and Mangalarga stallions in order to evaluated possible differences between breeds and whether there was a correlation with conception. Ninety-seven semen samples used for artificial insemination were analyzed, and at least 150 sperm heads per sample were examined for chromatin compaction and morphometric variables. Chromatin characteristics evaluated showed no significant correlation with conception, indicating low sensitivity of these smear methods to predict reproductive performance when ejaculates meet minimum quality standards. In contrast, morphometric variables showed a significant correlation, with the width/length ratio (r= -0,226; p= 0,0398) and ellipticity (r= 0,226; p= 0,0400) standing out, in addition to a moderate correlation for form factor (r= -0,211; p= 0,0556) and Fourier 0 (r= 0,172; p= 0,1210). Significant differences were also observed between breeds, although these did not impact conception rates. The results indicate that, while the evaluated chromatin methods are not effective predictors, computational sperm head morphometry shows potential as a complementary objective tool for estimating stallion fertility.

Avaliação otológica canina e sua relação com endocrinopatias: aspectos técnicos, micológicos e bacterianos

Tue, 24 Feb 2026 00:00:00 GMT

Title: Avaliação otológica canina e sua relação com endocrinopatias: aspectos técnicos, micológicos e bacterianos Abstract: Accurate assessment of canine otological microbiota is essential for proper diagnosis and management of otitis externa, one of the most common conditions in small animal practice. This thesis investigated technical, mycological, and bacterial aspects of canine otological microbiota, with emphasis on their relationship with endocrinopathies. Eighty dogs were evaluated, including 40 with hypothyroidism or hypercortisolism and 40 healthy controls, matched by age, sex, and breed. Animals underwent complete otological evaluation including otoscopy, auricular cytology, bacterial and fungal culture. For mycological analysis, hair samples were collected by manual traction or sterile vaginal cervical brush and inoculated in DTM medium for dermatophyte identification. Quantification of Malassezia spp. was performed by cytological evaluation, and bacterial samples were identified by MALDI-TOF, subjected to antimicrobial susceptibility testing using the VITEK system, biofilm formation capacity assessment by crystal violet method followed by microbiological counting of the sessile form, and ultrastructural analysis by scanning electron microscopy. Additionally, commercial and compounded propolis-based products were tested for antibiofilm efficacy. The prevalence of Malassezia spp. was significantly higher in endocrinopathic dogs (37.5%) compared to controls (10.0%; p<0.01), with dogs with otological malasseziosis presenting a 5.4-fold higher risk of being endocrinopathic (OR = 5.40; 95% CI: 1.60-18.20). Positive fungal culture for dermatophytes was identified exclusively in endocrinopathic dogs (5.0%). Different Staphylococcus strains were isolated, with all S. pseudintermedius strains demonstrating biofilm formation capacity (BFI>1.10) and variable antimicrobial resistance profiles. Results demonstrate strong association between endocrinopathies and opportunistic fungal infections, emphasizing the importance of endocrine investigation in recurrent otitis cases, and highlight the role of bacterial biofilms in persistence of otological infections.

Métodos de avaliação do processamento de grãos na ensilagem de milho planta inteira

Mon, 03 Aug 2026 00:00:00 GMT

Title: Métodos de avaliação do processamento de grãos na ensilagem de milho planta inteira Abstract: The evaluation of the degree of corn kernel processing is an important step in determining silage quality, as it directly influences starch availability and its utilization by ruminants. In this context, the present study aimed to compare the 4.75-mm sieve method and a digital image analysis method using the SilageSnap application for evaluating kernel processing during whole-plant corn ensiling. The experiment was conducted at Fazenda do Glória, belonging to the Federal University of Uberlândia, in the Dairy Cattle Sector (SEBOL), during the whole- plant corn ensiling period. Sixteen composite samples were collected directly from the material unloaded into the bunker silo before compaction. For the digital method, 20-g subsamples were washed with water to separate the kernels, prepared, and analyzed using the SilageSnap application. For the sieving method, 100-g subsamples were washed with water to separate the kernels, dried, sieved through a 4.75-mm sieve, and the percentage of particles passing through the sieve was determined. Data were analyzed using a completely randomized design, and means were compared by the F-test at a 5% significance level. The sieving method showed a mean of 53.97% of particles below 4.75 mm, whereas the SilageSnap application showed a mean of 61.36%, with a significant difference between the methods. The SilageSnap application showed potential as a tool for evaluating corn kernel processing, estimating higher percentages of particles below 4.75 mm than those obtained by the sieving method. Under the conditions in which this study was conducted, the sieving method proved to be more practical for field application.

Ixodofauna e circulação de Rickettsia parkeri em cães na região de Guaxupé em Minas Gerais

Fri, 07 Aug 2026 00:00:00 GMT

Title: Ixodofauna e circulação de Rickettsia parkeri em cães na região de Guaxupé em Minas Gerais Abstract: Ticks are hematophagous ectoparasites of extreme importance to public, human, and animal health, acting as vectors for many diseases, such as spotted fever. In Brazil, a wide variety of tick species is found distributed across different biomes and climates, with the genus Am-blyomma holding the greatest importance regarding public health. Considering its significance, recent studies highlight the relevance of Amblyomma ovale, which is responsible for harboring and transmitting the bacteria Rickettsia parkeri strain Atlantic rainforest. This bacteria causes a variant of Brazilian spotted fever that is, however, non-lethal and presents milder symptoms. Considering the dog as an important host for the adult stages of Amblyomma ovale, along with the interface between humans, dogs, and the Atlantic Forest, the favorable biome for this tick, we will seek to evaluate the occurence of this ectoparasite in the city of Guaxupé, Minas Gerais. Additionally, we aim to determine the presence of Rickettsia parkeri strain Atlantic rainforest in both ticks and host dogs with access to forest areas within the municipality. A total of 188 ticks were collected from 30 dogs, R. sanguineus linnaei (adults, n = 113), follo-wed by A. ovale (adults, n = 67), A. sculptum (nymphs, n = 4; adult, n = 1), and R. microplus (adults, n = 3). Of the 30 dogs with evaluated serology, 46.9% were seroreactive to R. parkeri, 50% to R. rickettsii, and 21.9% to R. bellii. The highest titers were found in 5 dogs for R. par-keri: 2 with a titer of 1024, 1 with 2048, and 2 with 4096. No amplification was observed for any rickettsial gene in the ticks subjected to DNA extraction and PCR. The tick with the highest intensity and abundance of infestation was R. linnaei, which is associated with dogs exhibiting more domiciled behavior, while the most prevalent was A. ovale, thus indicating the dogs' frequent access to humid forest areas, the habitat of this tick species. The occurrence of A. sculptum nymphs is associated with the study period coinciding with its peak activity sea-son and the predominance of this stage in dogs, and the R. microplus found is associated with the roaming behavior of dogs, accessing areas with cattle circulation, the host of this species. The dogs' serology showed high reactivity to spotted fever group (SFG) bacteria, with the highest titers for R. parkeri CMA. The correlation between dogs with high titers for R. parkeri CMA and the prevalence of A. ovale may indicate Guaxupé (MG) as a probable risk area for Atlantic rainforest spotted fever.