DSpace Coleção: Artigo em periódico indexado (CNPGL)

From satellites to the milking parlor: National Aeronautics and Space Administration prediction of worldwide energy resources as an information source for the national genetic evaluation of heat stress tolerance in Holstein and Gir cattle.

2026-06-08T11:48:37Z

Título: From satellites to the milking parlor: National Aeronautics and Space Administration prediction of worldwide energy resources as an information source for the national genetic evaluation of heat stress tolerance in Holstein and Gir cattle. Autoria: NEVES, M. P.; BIGNARDI, A. B.; SOUZA, A. B. S.; PEREIRA, R. J.; PEIXOTO, M. G. C. D.; BRUNELI, F. A. T.; ANDRADE, R. G.; COSTA, C. N.; BRITO, L. F.; SANTANA, M. L. Conteúdo: Heat stress is a major constraint to dairy productivity in tropical regions, where environmental conditions frequently exceed thermoneutral thresholds. The primary objective of this study was to quantify heat-related milk yield losses and estimate genetic parameters for thermotolerance in Brazilian Holstein and Gir cattle. In addition, because routine national genetic evaluations require complete and consistent environmental coverage, we evaluated the agreement between temperaturehumidity index (THI) values derived from the National Aeronautics and Space Administration (NASA) prediction of worldwide energy resources (POWER) and those obtained from ground-based weather stations to determine whether satellite-based data can serve as a reliable alternative environmental input. The phenotypic dataset included 2,161,001 first-lactation test-day milk yield (MY) records from 253,972 Holstein cows across 1,013 herds and 155,816 first-lactation records from 20,388 Gir cows across 316 herds. Three datasets were created by linking MY records to THI values derived from public weather stations (WS), NASA POWER (NASA), or both (NASAWS), allowing direct comparisons of phenotypic and genetic inferences across data sources. Random regression models incorporating DIM and THI were used to estimate genetic parameters and breeding values for heat tolerance. Divergent estimates of MY decline were observed between ground- and satellite-based data, with maximum average losses ranging from −0.440 to −0.367 kg/d per THI unit in Gir and −1.562 to −0.522 kg/d in Holstein. For Holstein, a consistent heat stress threshold was detected at 67 THI units, while thresholds in Gir varied from 70 to 75.853 depending on the data source. In contrast, estimates of additive genetic variance, heritability, and genetic correlations were nearly identical across meteorological sources, and sire ranking showed high consistency. Posterior heritability means (95% high posterior density intervals) in Holstein were 0.230 (0.217–0.243) for WS and 0.231 (0.218–0.244) for NASAWS; in Gir, values were 0.231 (0.195–0.269) for WS and 0.229 (0.194–0.267) for NASAWS. The genetic correlation between intercept and slope was consistently negative in both breeds (ranging from −0.428 to −0.397 in Holstein and from −0.282 to −0.275), confirming the antagonism between general production level and thermotolerance. The use of NASA POWER enabled broader spatial and temporal coverage, improved genetic prediction accuracy, and facilitated the identification of heat stress thresholds and associated losses. These results support the adoption of NASA POWER as a reliable and scalable alternative for genetic evaluations of heat tolerance, especially in regions with limited ground-based meteorological infrastructure.

Histopathological alterations in the synganglion of female Rhipicephalus linnaei ticks treated with essential oils of Egletes viscosa and Lippia schaueriana.

2026-06-08T12:48:35Z

Título: Histopathological alterations in the synganglion of female Rhipicephalus linnaei ticks treated with essential oils of Egletes viscosa and Lippia schaueriana. Autoria: PEREIRA, M. C.; ANHOLETO, L. A.; ABREU, M. R. de; CASTRO, K. N. de C.; CANUTO, K. M.; SOUZA, A. S. Q. de; CAMARGO-MATHIAS, M. I. Conteúdo: The inappropriate use of synthetic chemical acaricides for tick management has contributed to the selection of acaricideresistant tick strains, thereby stimulating the search for alternative and effective tick control strategies. Among these, the use of essential oils (EOs) derived from plants such as Egletes viscosa Less. (Asteraceae) and Lippia schaueriana Mart. (Verbenaceae) have shown promise in the control of insects and other arthropods. This study aimed to evaluate the effects of E. viscosa and L. schaueriana EOs on the morphohistology of the tick central nervous system (synganglion)—in Rhipicephalus linnaei semi-engorged females. The morphological alterations in the synganglion were assessed using histopathological and semi-quantitative analyses. The EOs, extracted via hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC–MS), revealed 27 constituents in E. viscosa and 18 in L. schaueriana, with cis-isopinocarveol acetate and piperitenone oxide identified as the predominant compounds, respectively. Histological and semi-quantitative analyses of the synganglion in EO-exposed females revealed dose-dependent alterations that were more severe than the mild vacuolization observed in the ethanol control group, primarily characterized by disruptions in the external membrane structures (neurilemma and perineurium), degeneration of the cortical region with hypertrophic, pyknotic, and fragmented neuronal nuclei, cytoplasmic vacuolization, and neuropil fiber disorganization. These findings suggest that the essential oils of E. viscosa and L. schaueriana induce histopathological damage in the synganglion, including neuronal cell damage and potentially impairing other central nervous system-mediated functions, such as feeding and reproduction. This supports the potential of these oils as candidates for the development of novel plant-based acaricides.

Response of italian ryegrass to osmotic shock: physiological indicators and protein profiles.

2026-06-06T12:54:05Z

Título: Response of italian ryegrass to osmotic shock: physiological indicators and protein profiles. Autoria: PASSOS, L. P.; SANTOS, A. S. de O. dos; MARTINS, M. F.; MITTELMANN, A.; FREITAS, J. C. E.; FOGAÇA, G. N. Conteúdo: A study was carried out to verify the effects of PEG-6000-induced osmotic shock on Italian ryegrass physiological processes and protein profiles determined by the microfluidic electrophoresis technique towards improving knowledge on the behavior of the species under drought. Sensitivity to osmotic shock was revealed by drastic drops in FW (fresh weight) and DW (dry weight) of most plant parts, chlorophyll content, shoot and root length, leaf area, leaf area ratio, specific leaf area and other physiological measures. As stress was intensified, there were reductions in leaf and solution ψs and osmotic adjustment was detected. Despite this reaction, the 0.97 MPa PEG-6000 treatment caused all plants to die within the last week of each trial. Electrophoresis analyses evidenced four 20.3, 24.4, 51.4 and 55.2 kDa protein bands whose peak areas increased sharply with stress from 0.25 MPa onwards. It is concluded that Italian ryegrass is readily injured by osmotic shock, and the damage is accompanied by the upregulation of four proteins. Further work to identify these proteins may offer new insights into understanding the species' initial responses to water deficit. The results obtained in this study open new perspectives for mitigating drought effects in Italian ryegrass.

Avaliação prévia da dinâmica folicular ovariana como indicador para iniciar protocolo de superovulação em cabras Toggenburg acíclicas

2026-06-06T12:53:41Z

Título: Avaliação prévia da dinâmica folicular ovariana como indicador para iniciar protocolo de superovulação em cabras Toggenburg acíclicas Autoria: GONÇALVES, J. D.; MAIA, A. L. R. e S.; ESTEVES, L. V.; SILVA, M. R.; SOUZA-FABJAN, J. M. G.; OLIVEIRA, M. E. F.; BRANDÃO, F. Z.; FONSECA, J. F. da Conteúdo: Este estudo avaliou a dinâmica folicular ovariana durante a indução do estro para identificar o melhor momento para iniciar a superovulação (SOV) em cabras Toggenburg acíclicas. No Experimento 1, cabras (n = 6) foram submetidas à indução do estro com esponjas (60 mg de acetato de medroxiprogesterona) por seis dias, associada a 37,5 μg de d-cloprostenol via laterovulvar (l.v.) no D0. A ultrassonografia ovariana foi realizada do D0 até a ovulação (D9). A população folicular (Classe 1, ≤ 3,9 mm) aumentou gradualmente, atingindo seu pico máximo no D4, no qual foram observados menos folículos de Classe 3 (5.0 a 5,9 mm) e Classe 4 (≥ 6 mm) em comparação à Classe 1 (P < 0,0001). Considerando o perfil folicular ovariano no Exp. 1, a SOV no Exp. 2 foi iniciada no primeiro dia que apresentou o maior número de folículos ≤ 3,9 mm, com apenas alguns folículos ≥ 6 mm (D4). As cabras foram divididas em dois grupos, superovuladas (GSOV, n = 10) ou não (Gnão-SOV, n = 10), posteriormente, submetidas à coleta não cirúrgica de embriões (CNCE). Não houve diferença na resposta ao estro entre Gnão-SOV (100 %) e GSOV (90 %) (P > 0,05). GSOV teve maior contagem média de corpos lúteos e maior média de estruturas recuperadas (10,8 ± 0,2 e 6,3 ± 0,8) em comparação com Gnão-SOV (1,6 ± 0,3 e 1,0 ± 0,2), respectivamente (P < 0,05). A taxa de estruturas viáveis foi maior em Gnão-SOV (60 %) em comparação com GSOV (10,5 %) (P < 0,05). O uso do perfil ovariano para superovulação em cabras acíclicas parece ser apropriado, no entanto, requer mais investigação, particularmente em relação ao momento da administração de hormônio folículo estimulante (FSH) dentro da onda folicular.