DSpace Communidade: Programa de Pós-Graduação em Reprodução Animal na Amazônia

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

Thu, 19 Mar 2026 00:00:00 GMT

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.

Aspectos reprodutivos de uma população de guará (Eudocimus ruber) sob cuidados humanos em baixa latitude.

Tue, 03 Jun 2025 00:00:00 GMT

Título: Aspectos reprodutivos de uma população de guará (Eudocimus ruber) sob cuidados humanos em baixa latitude. Autor(es): GONZÁLEZ GONZÁLEZ, Camilo Andrés Abstract: This thesis was divided into two chapters. In the first chapter, the objective was to describe the embryonic development of semi-altricial scarlet ibis (Eudocimus ruber) while identifying critical landmarks for diagnostic and age determination purposes, supporting both artificial incubation and field research on the species. We used eggs collected from a captive population in northern Brazil. A total of 50 embryos were analyzed from day 0 to day 18, focusing on external morphological traits observable through macroscopic examination. Key diagnostic features included the sequential formation of the beak, eyes, neck, feathers, and embryonic annexes. We compared the development of the semi-altricial scarlet ibis with reference descriptions of precocial and altricial species to evaluate the suitability of comparisons between different postnatal growth patterns. The semi-altricial scarlet ibis exhibited heterochronic variations of up to four days in critical developmental landmarks compared to precocial species with similar incubation periods. These findings suggest that developmental timelines. established for precocial species may not be reliable for accurately staging altricial and semi-altricial embryos. Interestingly, the median timing of significant developmental events in the scarlet ibis aligned more closely with those of other altricial species. The daily embryonic milestones described herein provide a valuable reference for scarlet ibis captive breeding programs and contribute to broader conservation efforts for other Threskiornithidae family members or species within the Pelecaniformes order, addressing the limited research on semi-altricial avian development. In the second chapter, we aimed to describe the breeding performance of a captive population of scarlet ibis over a three-year period (2022, 2023, and 2024). We focused on various factors, including the onset and conclusion of the breeding season, couple formation, enclosure density, and laying timing. We conducted statistical analyses to assess the impact of breeder-related factors (such as age and laying timing), egg characteristics (including weight and shape), and incubation parameters (such as egg weight loss) on key zootechnical variables commonly used in poultry production, including laying rate, fertility, and hatchability. Our goal was to establish a breeder profile that could inform mate selection. The onset of the breeding season varied between July and August over the three years, while its conclusion ranged from November to January. Both males and females began forming breeding pairs as early as two years old, with the oldest pairing ages being 20 years for males and 12 years for females. 82,6 ± 4.9% of pairs were monogamous throughout the season. Higher enclosure densities appeared to improve laying rates and encourage earlier laying, while a 1:1 male-to-female ratio facilitated effective pair formation with minimal aggression. Additionally, increased female age correlated with a higher laying rate (p < 0.05). Egg withdrawal stimulated the replacement of eggs in females, resulting in an average of 7.6 ± 2.7 new eggs. The advancement of the laying season significantly influenced initial egg weight (p < 0.01). The median daily weight loss during incubation was 0.74% (tau = 0.5), while the mean weight loss on day 21 was 19 ± 2%. The findings from this study are invaluable for planning efficient breeding programs for the scarlet ibis and potentially for other members of the Threskiornithidae family.

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

Tue, 08 Apr 2025 00:00:00 GMT

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

Mon, 29 Aug 2022 00:00:00 GMT

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.