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Estoques de carbono, nitrogênio e emissões de gases de efeito estufa sob diferentes condições ambientais em sistemas agropecuários na Amazônia Oriental.

2025-09-23T17:51:21Z

Título: Estoques de carbono, nitrogênio e emissões de gases de efeito estufa sob diferentes condições ambientais em sistemas agropecuários na Amazônia Oriental. Autor(es): MORAES, Lorena Maués Abstract: Land use changes in the Amazon can affect soil carbon (C) and nitrogen (N) stocks and intensify greenhouse gas (GHG) emissions. This study aimed to evaluate the effects of land use on C and N stocks and C origin, as well as the effects of land use, nitrogen fertilization, and temperature on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in soils from the Eastern Amazon. The study was conducted in three municipalities in the state of Pará with different Köppen climates classifications: São Miguel do Guamá (Af), Capanema (Am), and Paragominas (Aw). Soil C and N stocks and C origin were evaluated in Af and Aw climates, while GHG emissions were quantified in incubation experiments using soils from the Am climate (land use effect) and Af climate (land use, fertilization, and temperature effects), under four land use types: forest, agriculture, intensive pasture, and nominal pasture. In the Af climate, soil C stocks ranged from 27.6 to 42.4 Mg ha−1 (0–30 cm) and from 59.4 to 75.5 Mg ha−1 (0–100cm), with no differences (p > 0.05) among land uses. For N, significantly higher stocks (p< 0.05) were observed under intensive pasture (3.2 Mg ha−1 at 30 cm and 5.3 Mg ha−1 at 100 cm). In the Aw climate, C stocks ranged from 63.9 to 77.4 Mg ha−1 (0–30cm) and from 117.1 to 134.5 Mg ha−1 (0–100cm), while N stocks ranged from 5.2 to 5.8 Mg ha−1 (0–30cm) and from 9.8 to 10.8 Mg ha−1 (0–100cm), with no differences (p > 0.05) among land uses. The δ13C isotopic analysis indicated substitution of forest-derived C by C4-C up to 60 cm in Af and up to 20cm in Aw, reflecting greater incorporation in wetter soils. In the Am climate, the highest cumulative CO2 emissions (246.0mg g−1) were recorded in the nominal pasture, while the highest N2O flux (64.3ng g−1) occurred in the intensive pasture. For CH4, all land uses acted as sinks, with greater oxidation observed in pastures (–199.7 to –249.3ng g−1) and lower oxidation in forests (–49.0 ng g−1). In Af, the highest CO2 (248.6mg g−1), N2O (175.4ng g−1), and CH4 (237.0 ng g−1) fluxes were also observed in soils under intensive pasture. Application of 180kg N ha−1 increased CO2 and N2O emissions, while CH4 showed a quadratic response, decreasing at higher doses. Temperatures of 30–35°C intensified GHG fluxes, while 45°C reduced all emissions. It is concluded that soil C and N stocks vary according to soil type, climate, and land use, and that intensive use increases GHG fluxes, with effects amplified by fertilization and temperature. Sustainable strategies, tailored to climate and soil conditions, are essential to mitigate environmental impacts on the biogeochemical functioning of Amazonian soils.

Novos polimorfismos dos genes LALBA e OLR1 e suas associações com características de produção de leite em búfalas.

2025-06-06T20:44:56Z

Título: Novos polimorfismos dos genes LALBA e OLR1 e suas associações com características de produção de leite em búfalas. Autor(es): SANTOS, Cintia Luana Pinheiro Abstract: Buffaloes play a notable economic, social, and environmental role worldwide. Their milk is the second most produced and has excellent nutritional composition. In the meantime, it is necessary to understand the genetic factors by searching for the mechanisms that can influence the productivity of production animals. Therefore, the objective was to investigate single-nucleotide polymorphisms (SNPs) in protein and lipid metabolism genes, to associate them with data on milk production in buffaloes from the Amazon region. For this purpose, blood samples were collected from 85 females belonging to a property in the municipality of Bujaru/PA. DNA extractions were performed using the phenolic method, followed by Polymerase Chain Reaction (PCR), Purification, and Sequencing of the coding regions of the LALBA (833 bp) and OLR1 (750 bp) genes. The possible binding sites to transcription factors in both genes were investigated by the Nsite v. 1.0 Software. 5. Furthermore, for the LALBA gene, the mRNA from milk epithelial cells was extracted to determine the expression profile in seven haplotypes selected in the population. After editing and sequence alignments, fourteen SNPs were found in total, ten in the LALBA gene and four in the OLR1 gene. One SNP of the InDel type in the LALBA gene stood out. None of the fourteen SNPs detected showed a significant association with the average milk production of the population (P>0.05). Six of the ten SNPs observed in LALBA showed allele frequencies of wild-type nucleotides greater than 0.5, with 90% in Hardy-Weinberg equilibrium (HWE), with SNP -42 (A>G) presenting a strong binding site for the transcription factor hepatocyte nuclear factor 3 (HNF3). Expression analysis showed that haplotypes 4 and 2 showed the highest expression levels compared to the others (P<0.05). Two of the four SNPs found in the OLR1 gene were of the transition type, and the other two were of the transversion type, all with high wild-type nucleotide allele frequencies above 0.90, with 75% under EHW conditions. However, for the SNPs at positions -555 InDel (TAAA) and -720 (C>T) found in the LALBA gene, as well as the one at position -672 (A>T) in the OLR1 gene, it was revealed that the heterozygotes exhibited higher average milk production values compared to the homozygotes and may, therefore, be subject to selection in the population for increased milk volume production in both. Thus, both the higher levels of LALBA mRNA expression observed in buffalo milk in two different haplotypes and the presence of heterozygous individuals with higher milk production, especially the Indel found in LALBA -555 (TAAA) and the SNP in OLR1 -672 (A>T), were candidates due to the additional effect that new alleles carry, causing greater genetic variability within the herd. Therefore, they may be desirable characteristics to be fixed in the population. However, more approaches focused on the relationship between point mutations and expression levels in somatic cells of milk, together with other genes that may be influencing milk production levels, should be carried out to investigate whether these variants can be proven through the phenotypes of the animals.

Produção e qualidade de produtos cárneos de cabras terminadas com dietas contendo linhaça inteira.

2025-02-06T18:36:30Z

Título: Produção e qualidade de produtos cárneos de cabras terminadas com dietas contendo linhaça inteira. Autor(es): OLIVEIRA, Felipe Brener Bezerra de Abstract: The objective of this study was to evaluate the inclusion of whole flaxseed in the finishing of adult goats on performance, carcass characteristics, and fat deposits. Eighteen non-lactating adult crossbred Anglo-Nubian goats (3.8 ± 0.7 years; mean ± SD) from the herd of the Experimental Farm of the State University of Ceará were used. The animals were divided into two groups: without whole flaxseed (WFFLG, n = 9) and with whole flaxseed (FFLG, n = 9), with diets containing 2.7% and 6.9% ether extract, respectively. The supplementation period lasted 28 days, and slaughter was performed 48 hours after the end of supplementation. Additionally, a meat product was manufactured, and the quality parameters of the shoulder meat were evaluated before, during, and after the curing and smoking process. The analyses related to carcass and meat quality characteristics were conducted in the days following slaughter at the Ruminant Nutrition and Production Laboratory. The meat cuts were stored in a freezer (-20 ºC) for the subsequent production of smoked shoulders. The dry curing process was performed on the fresh shoulder using salts and spices, followed by storage at 4°C for 72 hours to complete the curing process. The smoking process lasted 6 hours, and in the final 2 hours, Astronium lecointei wood chips were added to the brazier to produce smoke. The meat was considered fully cooked when the internal temperature of the shoulder reached approximately 75°C. All data were subjected to a normality test (Kolmogorov-Smirnov test) and a homoscedasticity test (Bartlett’s test). A completely randomized design was used to evaluate the effects of the diets on the observed parameters. To assess the effect of diets and evaluation time during smoking and their interactions on color and pH, the ‘Proc MIXED’ command in SAS 9.0 software was used. Mean comparisons were performed using Tukey’s test. The performance results showed that finishing with flaxseed (FFLG) did not influence (p > 0.05) body weight, morphometric measurements, body condition, or weight gain. However, the FFLG group showed higher values of feed intake relative to metabolic weight and percentage of live weight (p < 0.05). The internal fat in the sternal region was significantly affected by supplementation (p < 0.05), being higher in the FFLG group, while other body fat deposits were not influenced by diet type. Regarding meat product manufacturing, the physicochemical attributes of raw shoulder meat did not vary according to the experimental diets. However, colorimetric parameters and pH changed during the curing and smoking process. Multivariate analysis of the first two principal components (PC) identified key variables contributing to total variation (L*, a*, b*, C*, h*, and fat content) in raw and smoked meat. Fat content and b* color showed the highest scores for variable importance. The use of flaxseed did not negatively affect animal performance, carcass quality, meat quality, or fat deposits. Supplementation with flaxseed in adult goats did not influence the physicochemical quality parameters of raw shoulder meat. However, after curing and smoking, there was a significant effect of diet on the Hue angle (h*).

Avaliação dos parâmetros morfofisiológicos como biomarcadores em primatas neotropicais relevantes para pesquisa biomédica.

2026-02-05T19:58:59Z

Título: Avaliação dos parâmetros morfofisiológicos como biomarcadores em primatas neotropicais relevantes para pesquisa biomédica. Autor(es): SILVA, Gessiane Pereira da Abstract: Non-human primates (NHP) are a varied group and have many behavioral and physiological similarities with humans. For this reason, they are excellent comparative models for biomedical, evolutionary, and aging studies. Thus, it is essential to monitor the health of NHP using health and senescence biomarkers, which include routine tests such as hemograms, serum biochemistry, hormone levels, and imaging tests. The main group of hormones used to assess stress and well-being are glucocorticoids (GC), but attempts have been made to associate GC with other markers, such as dehydroepiandrosterone sulfate (DHEAS), for a more accurate assessment of the condition of these animals. Thus, Chapter 1 is a review regarding the use of the squirrel monkey (genus Saimiri) as an experimental model for studies of pelvic disorders in women, discussing the main similarities and differences found. Chapter 2 approaches the validation of the DHEAS assay in howler monkeys (Alouatta caraya), owl monkeys (Aotus azarai), and capuchin monkeys (Sapajus apella), in feces and blood samples. Chapter 3 consists of renal evaluation using ultrasound and laboratory tests in howler monkeys (n = 20) and capuchin monkeys (n = 21), considering the effects of sex and age. And Chapter 4 considered the results of blood tests and serum biochemistry and focused on howler monkeys (n = 20) and capuchin monkeys (n = 21). In general, it was observed that the squirrel monkey is a good comparative model for the study of pelvic disorders in women. In addition, the validation of DHEAS assay in blood and feces samples from the three studied species was confirmed by the increase in the target hormones, the parallelism, and precision tests, showing higher concentrations in howler monkeys. In the renal evaluation, differences between genders, ages, and species were found, suggesting that howlers have a faster aging mechanism than capuchin monkeys, however, high metabolic demands in the latter. In the hematological and serum biochemistry tests, the effect of species, sex, age, and level of parasitism on several parameters was observed. Therefore, the NHP, especially the platyrrhines, are important animals in biomedical and comparative morphophysiology studies. The differences found in the biomarkers of these species may indicate how they adapt to habitat and management conditions, and the implications of this for the survival of these animals and demonstrate the clinical relevance for assessing animal health and the adequacy of the creation of these programs.