DSpace Coleção: Mestrado em reprodução animal na Amazônia

Exposição aguda à amônia compromete a reprodução e a viabilidade embrionária do lambari Amazônico Astyanax bimaculatus (Linnaeus, 1758).

2026-03-20T18:31:23Z

Título: Exposição aguda à amônia compromete a reprodução e a viabilidade embrionária do lambari Amazônico Astyanax bimaculatus (Linnaeus, 1758). Autor(es): FERREIRA, Evagno Junior da Silva Abstract: This study evaluated the effects of acute ammonia exposure on the reproduction and embryonic and larval viability of the Amazonian tetra species (Astyanax bimaculatus). Adult breeders were exposed to a sublethal concentration of ammonia (NH₄Cl, 180 mg/L) for 4 hours before artificial reproduction. The results showed a significant reduction in hatching rates (82.3 ± 0.577 (41,2%) vs. 129 ± 1.73 (64,5%) in the control) and an acceleration in hatching time (1005 ± 2.58 vs. 1026 ± 3.65 minutes). Gonadal histology revealed alterations in gametogenesis, with exposed females exhibiting fewer vitellogenic oocytes and a higher number of post-ovulatory follicular complexes, while males presented a larger number of spermatocytes and interstitial tissue, and a reduction in spermatozoa. In both cases, indicating early release of gametes. Morphometric analysis of larvae from exposed breeders indicated delayed growth at 10 days post-hatching, although no morphological abnormalities were observed. These findings demonstrate the impact of ammonia on reproductive success and larval development in fish, emphasizing the importance of strict water quality management in aquaculture to mitigate such effects.

Avaliação do gene do hormônio anti-mulleriano (AMH) em fêmeas bubalinas submetidas à sincronização de cio, na Amazônia.

2025-04-10T13:11:21Z

Título: Avaliação do gene do hormônio anti-mulleriano (AMH) em fêmeas bubalinas submetidas à sincronização de cio, na Amazônia. Autor(es): FIGUEIREDO, Juliana Vasconcelos Abstract: Reproductive management in buffaloes is essential for the productivity of the Brazilian agricultural sector, especially in the Amazon region. The anti-Müllerian hormone (AMH) is considered a significant marker of ovarian reserve, and understanding the relationship between genotypes and fertility is important for sustainable livestock production. Thus, the present study aimed to investigate the presence of polymorphism in exon 5 of the AMH gene and its associations with the reproductive efficiency of female buffaloes. The research was conducted with 54 multiparous Murrah breed buffaloes, located on a farm in the municipality of Bujaru, Pará. The females were subjected to a fixed-time artificial insemination (FTAI) protocol. Initially, all females selected for the study were non-pregnant. Only after estrus synchronization and pregnancy diagnosis were the animals subdivided into two groups: pregnant and non-pregnant. Blood collection for DNA extraction and ultrasonographic evaluation of the ovaries were performed on day 11 of the protocol.Following collection, DNA extraction was carried out, and the AMH gene was amplified using the PCR technique; subsequently, the products were purified for sequencing. Statistical analyses were performed using SAS software, with a significance level of 0.05, and ANOVA methods were employed to compare the means of reproductive variables.The results showed the absence of polymorphisms in exon 5 of the AMH gene in buffaloes. However, a significant difference was observed in antral follicle count (AFC) via transrectal ultrasonography between pregnant and non-pregnant buffaloes (p = 0.02). Additionally, variables such as ovarian volume (V) and dominant follicle (DF) did not present significant differences, suggesting these factors may play a less prominent role in reproductive performance. These findings demonstrate the conservation of the AMH gene and highlight the presence of antral follicles as predictors of reproductive efficiency in this study. The research underscores the need for future studies in other regions of the AMH gene and the association with genetic factors that may influence fertility. Finally, the results presented contribute to the development of more effective future strategies in assisted reproduction, aiming to increase productive efficiency in buffalo herds in the Amazon region.

Biomarcadores bioquimicos sericos de bezerros bubalinos do nascimento aos 18 meses de idade

2026-02-02T20:00:17Z

Título: Biomarcadores bioquimicos sericos de bezerros bubalinos do nascimento aos 18 meses de idade Autor(es): SANTOS, Jamyle Carollyne Melem Abstract: The biochemical profile analysis of animals is fundamental in their clinical evaluation and determination of animal welfare, including the diagnosis of diseases. Factors such as diet, productive category, sanitary management, age and race can directly influence biochemical markers. Thus, the present study aimed to evaluate the influence of age on biochemical biomarkers of buffalo calves from birth to 18 months of age. The study was carried out at Eva Daher Abufaiad Dairy Bubalinoculture Unit Vivarium at the Federal Rural University of Amazonia, Belém, Pará. Twenty-four animals of the buffalo species were used, evaluated from birth, weekly during the first month and, from then on, monthly until 18 months. The animals underwent clinical evaluation, and after being considered healthy, the samples were collected for the following laboratory analysis: urea, total cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), total proteins (EN), albumin, phosphorus, magnesium, creatine kinase (CK), iron, c-reactive protein (CRP), ferritin, chloride, fructosamine and creatinine. Several factors can interfere with the results of serum biochemical analyses, including the age grou[p and the stage of development in which the animal is. In the present study, it was possible to observe that the neonatal period is the one with the greatest influence over the results of the analysis carried out, followed by the feeding transition period, in which the calf starts to consume forage and is no longer just an infant.

Efeitos do uso da castração imunológica no epitélio seminífero de machos bubalinos.

2023-04-24T18:46:48Z

Título: Efeitos do uso da castração imunológica no epitélio seminífero de machos bubalinos. Autor(es): SILVA, Leonardo Reis Abstract: The immunocastration procedure has been used as an alternative technique that is widely favorable to animal welfare, as it is painless, little invasive and with similar effectiveness to surgical castration, which causes greater stress to animals, especially when performed improperly. Immunocastration stimulates the production of antibodies against the Gonadotropin Releasing Hormone (GnRH), temporarily blocking the production of testosterone by the male gonads and consequently spermatogenesis. Due to the scarcity of information about this procedure in buffalo bulls, the study aimed to analyze the possible effects of immunocastration on the testis of these animals. Twenty buffalo bulls, aged 4 to 6 years, from the island of Marajó - PA, were evaluated and randomly divided into two groups consisting of ten animals in the control group (CG) and ten in the immunocastrated group (GIM). The product used was the Bopriva ® anti-GnRH vaccine (Zoetis, SP, Brazil). The GIM received two doses of 1.0 ml containing 400μg of the Bopriva ® vaccine with an interval of 60 days and the control group received 1.0 ml of saline solution. Fourteen days after the last dose, the animals were slaughtered for consumption and the 20 pairs of testicles were collected for analysis of macroscopic parameters such as: length, width, circumference and weight. In addition, fragments of the testicular parenchyma were removed from the medial portion to make histological slides. For data comparison, Student's t test was applied considering significance with p<0.05 and 95% confidence interval. A significant difference was observed between the two groups for groups for weight (right p<0001; left p≤ 0.0001), circumference (right p<0.0001; left p<0.0001), width (only right-side p< 0.0372) and length (right p≤ 0.0013; left p<0.0437). In the microscopic evaluation, the animals of the CG did not present alterations. In the animals from the GIM, there was degeneration in all samples, with desquamation, tortuosity and thickening of the basement membrane of the seminiferous tubule being visualized, as well as vacuolation and atrophy of Sertoli cells. A reduction in the number of Leydig cells, pyknotic and azoosperm nuclei was also observed. It is concluded that anti-GnRH vaccine may compromise fertility in buffaloes, probably by suppressing testicular function. Probable suppression of testicular function was demonstrated through the analysis of macroscopic changes and testicular degeneration and atrophy at the histological level observed in immunocastrated animals.