DSpace Coleção:

Compostos fenólicos hidrofílico e lipofílico na dieta de porcas durante a gestação e lactação sobre o desempenho produtivo e reprodutivo

2026-06-23T11:37:41Z

Título: Compostos fenólicos hidrofílico e lipofílico na dieta de porcas durante a gestação e lactação sobre o desempenho produtivo e reprodutivo Autor(es): Vieira, Eloisa Helena Mendes Abstract: The objective of this study was to evaluate the effects of hydrophilic and lipophilic phenolic compound supplementation in the diet of sows during gestation and lactation on productive performance, colostrum and milk composition, hematological and biochemical parameters, and antioxidant enzyme activity in sows and piglets. A total of 300 highly prolific sows were distributed in a completely randomized design with a 4 × 3 factorial arrangement, considering four parity orders (1st, 2nd, 3rd–4th, and 5th–6th) and three supplementation levels (0, 200, and 400 mg/day). Blood samples from sows and piglets, as well as colostrum and milk samples, were collected for laboratory analyses. No interaction was observed between supplementation and parity order. Supplementation reduced oxidative stress in sows, evidenced by lower malondialdehyde concentrations and higher superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, in addition to altering blood triglyceride levels. Colostrum from sows supplemented with 400 mg/day showed higher fat content. In piglets, maternal supplementation increased total cholesterol, LDL cholesterol, total phenolic compounds, and SOD and GPx activities, while reducing C-reactive protein levels. Parity order influenced productive performance, milk composition, and litter performance parameters. First-parity sows had fewer piglets born, whereas second-parity sows showed greater milk production. Piglets from 1st- and 5th–6th-parity sows showed lower performance compared with those from 2nd-parity sows. It was concluded that supplementation with hydrophilic and lipophilic phenolic compounds did not affect productive parameters but improved the antioxidant status of sows and piglets. Tipo: Tese

Criação e manejo de duas espécies de abelhas solitárias das tribos Anthidiini e Megachilini (Hymenoptera: Megachilidae) no Nordeste do Brasil

2026-06-22T21:31:02Z

Título: Criação e manejo de duas espécies de abelhas solitárias das tribos Anthidiini e Megachilini (Hymenoptera: Megachilidae) no Nordeste do Brasil Autor(es): Cavalcante, Arianne Moreira; Cavalcante, Arianne Moreira Abstract: Solitary bees that nest in pre-existing cavities constitute important models for the study of reproductive biology and present potential for management strategies aimed at conservation and pollination. However, for many Neotropical species, especially in anthropized environments, there are still significant gaps in knowledge about their bionomics and response to management. In this context, this thesis investigated the nesting biology, reproductive traits, and rearing potential of two species of Megachilidae, Dicranthidium arenarium (Anthidiini) and Megachile (Ptilosarus) cf. xanthura (Megachilini), in an urban area in Northeast Brazil. The study was conducted between August 2021 and November 2023, through the installation of trap nests with cavities of different dimensions. Nesting activities were monitored daily, and females of both species were individually marked, allowing continuous tracking from cavity occupation to adult emergence of their brood. The study evaluated aspects related to nesting behavior, nest architecture, reproductive effort, sex ratio, mortality, seasonality, and the influence of environmental variables, as well as the species' response to management interventions, such as the provision of nesting materials. D. arenarium predominantly used plant resin in nest construction, with flexibility in the use of alternative materials such as meliponine wax and resin. It demonstrated a preference for longer cavities (10 cm), a sex ratio skewed towards males, and an absence of significant correlation between nesting activity and climatic variables. The availability of nesting materials mitigated robbing and favored an increase in nesting, highlighting the importance of these resources as a limiting factor. The species exhibited behaviors that are still poorly understood, such as the prolonged stay of females inside the nest after oviposition. On the other hand, Megachile (P.) cf. xanthura built nests exclusively with leaf fragments, exhibited high reproductive efficiency and strong seasonality, with activity concentrated in periods of higher temperature and lower humidity. This species showed a sex ratio biased towards females, low incidence of parasitism, and a high rate of return to the emergence site, characteristics associated with good performance in trap nests. These results indicate potential for use in management programs and directed pollination. In an integrated way, the results demonstrate that both species respond positively to the use of trap nests but differ in the factors that influence their reproductive success. While D. arenarium is more sensitive to the availability of nesting materials, M. (P.) cf. xanthura responds mainly to climatic conditions. These results highlight that management strategies must consider the specific ecological requirements of each species. Thus, this work expands knowledge about the biology of solitary bees in Northeast Brazil and provides practical support for the development of management techniques aimed at the conservation, monitoring, and potential use of these species in pollination and environmental restoration programs. Tipo: Tese

Manejo da adubação nitrogenada em capim-marandu sob pastejo: respostas da planta e do animal e dinâmica de carbono e nitrogênio no solo

2026-06-12T23:00:06Z

Título: Manejo da adubação nitrogenada em capim-marandu sob pastejo: respostas da planta e do animal e dinâmica de carbono e nitrogênio no solo Autor(es): Freitas, Roberta Santos de Abstract: Approximately 50 to 70 percent of Brazilian pastures are in a state of degradation, which requires technological alternatives to improve forage quality and productivity. This study aimed to evaluate the effects of different nitrogen sources and application strategies on the agronomic characteristics of Marandu grass, cattle performance, and soil carbon (C) and nitrogen (N) stocks. The experiment was conducted at Tocantins Federal University (UFT) over two experimental years (2022-2023), with an 84-day experimental period per year, divided into three 28-day cycles. Urea (UR) and ammonium nitrate + calcium (NA) were tested under two application methods, single application (AU) and split applications (AP), in a 2×2 factorial design with three replicates. In the first year, 150 kg N ha⁻¹ was applied, and in the second year, 75 kg N ha⁻¹. Male cattle were used, with an average weight of 349.26 kg in the first year and 287.17 kg in the second year, distributed across 12 experimental paddocks of 0.33 ha each, with two animals per paddock. Animal performance was evaluated by weighing at each cycle, and forage samples were collected for agronomic and chemical and bromatological analyses. Litter was collected and analyzed for biomass, total nitrogen, organic matter (OM), and total carbon (TC). Carbon and nitrogen assessments were performed to estimate the soil C and N stocks by dry combustion. The use of NA fertilizer resulted in greater plant height (41.53 cm), higher organic matter content (923.6 g kg⁻¹), and litter carbon (567.01 g kg⁻¹) in the second year, compared to urea (34.85 cm; 877.40 and 545.71 g kg⁻¹, respectively). In the first year, the URAU fertilization reduced the crude protein content of the forage from 13% to 8%. In the second year, urea promoted higher leaf production in the first cycle but reduced it in the following cycles. Split fertilizer application resulted in a higher leaf blade/stem ratio in both years and greater animal productivity gains in the first year (TPG = 66.25 kg animal⁻¹; ADG = 0.789 kg animal⁻¹; TPA = 401.52 kg ha⁻¹; CY = 13.38 @ ha⁻¹). The use of NA resulted in higher C stocks up to 40 cm (32.82 and 20.61 Mg ha⁻¹) and higher N stocks in the 0–20 cm layer (2.02 Mg ha⁻¹), while split fertilization increased nitrogen content and stock in the 60–80 and 80–100 cm layers (0.600 and 0.370 Mg ha⁻¹, respectively). The use of NA as a nitrogen fertilizer increases the proportion of leaves with higher crude protein content and enhances soil C and N stocks in the upper layers. Split nitrogen fertilization, regardless of fertilizer source, is a promising management strategy, as it improves animal productivity, forage and litter quality, and nitrogen stocks in deeper soil layers. Tipo: Tese

Respostas termofisiológicas e reprodutivas de carneiros deslanados submetidos a estresse térmico moderado induzido por insulação escrotal

2026-06-08T22:56:08Z

Título: Respostas termofisiológicas e reprodutivas de carneiros deslanados submetidos a estresse térmico moderado induzido por insulação escrotal Autor(es): Araújo, Alan Martins de Abstract: This study investigated the effects of heat stress on thermoregulatory and reproductive responses in hair sheep, using scrotal insulation as an experimental model. Seven adult rams were subjected to scrotal insulation for seven consecutive days in a longitudinal design consisting of pre-insulation (4 weeks), insulation (1 week), and post-insulation (9 weeks). Four semen collections were performed during the pre-insulation phase and nine during the post-insulation phase, with continuous environmental monitoring. During insulation, thermophysiological parameters were recorded after 24 h (D2) and 96 h (D4). Semen was evaluated for sperm kinetics by CASA, concentration, morphology, DNA integrity, and binding pattern of Ram Seminal Vesicle Proteins (RSVPs) by immunocytochemistry. Reproductive variables were analyzed using the Friedman test, while individual thermotolerance was determined by principal component analysis (PCA), with group comparisons performed using the Kruskal–Wallis test. The maximum recorded temperature was 35.1 °C and the minimum was 25.8 °C. Relative humidity ranged from 84.1% to 45.0%. Scrotal insulation increased scrotal surface temperature by 0.75 °C and epididymal tail temperature by 0.90 °C compared with pre-insulation values (33.25 °C and 31.75 °C), without changes in rectal or ocular temperature. Thermal gradients decreased during insulation, from 3.00 °C to 1.96 °C (ocular–scrotal) and from 7.35 °C to 6.01 °C (rectal–epididymal), with recovery after insulation removal. Total motility decreased (p < 0.05) from 85.2 ± 2.2% to 40.6 ± 13.6% in the second post-insulation week, reaching 23.4 ± 10.4% in the fourth week, with recovery by the sixth week (67.7 ± 6.2%; p > 0.05). Progressive motility declined from 80.4 ± 2.5% to 38.3 ± 13.2% and 19.2 ± 8.9%, returning to 59.1 ± 6.9% in the sixth week. Scrotal circumference varied from 30.3 ± 0.7 cm (pre-insulation) to 31.4 ± 0.6 cm (p > 0.05) and decreased to 28.6 ± 0.5 cm in the third week (p < 0.05). Normal morphology dropped from 89.9 ± 4.2% to 39.7 ± 13.2% in the third week, recovering to 75.8 ± 5.6% in the seventh week (p > 0.05), while major defects increased from 4.9 ± 2.3% to 53.9 ± 9.9% in the fifth week. DNA integrity decreased from 92.9 ± 1.5% to 78.1 ± 1.7%, reaching 24.1 ± 9.8% in the fourth week, with recovery to 88.1 ± 1.4% in the seventh week. RSVP binding intensity declined from 3.8 ± 0.7 × 10⁶ AU to 0.7 ± 0.2 × 10⁶ AU, normalizing by the seventh week. PCA distinguished low- and high-thermotolerance groups, with HTT animals showing higher (p < 0.05) total motility (73.6 ± 2.7% vs. 62.2 ± 4.7%), progressive motility (68.2 ± 2.9% vs. 58.7 ± 4.5%), concentration (3.2 ± 0.07 × 10⁹ vs. 2.8 ± 0.1 × 10⁹ sperm/mL), and DNA integrity (81.2 ± 2.6% vs. 70.2 ± 4.4%). In conclusion, seven days of scrotal insulation impair thermoregulation and induce reproductive losses, with heterogeneous responses among animals, highlighting interindividual variability under heat stress. Tipo: Dissertação