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1.
Poult Sci ; 103(5): 103662, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38547539

RESUMEN

Hatchery performance is often evaluated based on descriptors such as hatchability, 7-d mortality, and cost. In addition to these descriptors, it is useful to include in this analysis aspects of chick quality through post-hatch performance. Realizing the bird's complete genetic potential necessitates meeting various criteria, with effective support for the chick's immune system being among the pivotal factors. To be effective, in ovo vaccination systems must deliver the vaccines to specific sites in the egg, a circumstance that directly depends on when the injection is made. We examined production data to evaluate the impact of in ovo vaccination time on performance parameters of male Ross308AP chicks. A comprehensive survey was conducted examining records from 3,722 broiler flocks produced and raised by the same company under standard nutrition and management conditions. The selected data specifically pertained to flocks that underwent slaughter between 41 and 45 d. In our analysis, 4 different linear models were built, one for each response variable: mean weight (MW), body weight gain (BWG), corrected feeding conversion rate (cFCR), and total mortality (TM). The linear models used in the analyses included as main predictor the timing of in ovo vaccination (440, 444, 448, 452, 456, 458, and 460 h of incubation), and as additional predictors: age of the breeding flock (26-35, 36-55 and 56-66 wks old), slaughter age, identity of the hatchery, and the season at which the data was collected. Our results showed that the timing of in ovo vaccination significantly affected BWG and cFCR, with procedures performed at 460 h of incubation showing the best outcomes. Breeding flock age affected all response variables, with older breeding flocks delivering increased MW, BWG and TM, and middle-aged flocks increased cFCR. Increasing slaughter age reduced BWG while MW, cFCR and TM were all increased. These data emphasize the benefits of performing in ovo vaccination as close as possible to 460 h of incubation to extract the best BWG and cFCR from Ross308AP male broiler.


Asunto(s)
Pollos , Vacunación , Animales , Pollos/fisiología , Pollos/crecimiento & desarrollo , Masculino , Vacunación/veterinaria , Óvulo/fisiología , Factores de Tiempo , Enfermedades de las Aves de Corral/prevención & control , Enfermedad de Newcastle/prevención & control
2.
Sci Rep ; 13(1): 4385, 2023 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-36928378

RESUMEN

We explore the potential factors that affect clutch initiation in four Neotropical large raptors (Harpy eagle-HE, Crested eagle-CE, Ornate hawk-eagle-OHE, and Black hawk-eagle-BHE) by analyzing 414 clutch events mostly obtained from captive individuals. Differences in how clutch initiation is associated with changes in photoperiod were found between HE and both hawk-eagles, and between CE and BHE. Changes in temperature at the time of clutch initiation only differed between HE and OHE, whereas changes in precipitation varied between BHE and all other species. Principal Component Analysis of these environmental cues showed that ellipses in the dataset of each species overlap, but only ellipses from CE and OHE had the same variation trends. This means that although these species live under similar ecological conditions, they exhibit three different patterns of response to environmental cues. Apparently, these patterns are not associated with phylogenetic relatedness because species belonging to the same clade do not show the same response pattern. Diet diversity analysis revealed that HE has the least varied diet, and CE and OHE the most varied diet. The fact that species who fit the same reproductive timing response to environmental cues show similar diets leads us to hypothesize that breeding in these eagles was most likely shaped by food availability.


Asunto(s)
Águilas , Humanos , Animales , Águilas/genética , Filogenia , Bosques , Dieta , Alimentos
3.
Am Nat ; 199(6): 804-807, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35580229

RESUMEN

AbstractA pressing issue is to understand how biological complexity impacts the persistence and adaptation of populations. Natural environments are under unprecedented pressure as a result of climate change and land use change, which makes biological populations and ecological communities vulnerable. Evolution by natural selection-that is, genetic change in response to selection-is one important way species can cope with such changes. Selection often operates on complex traits, and much of selection is due to ecological interactions that, in turn, often form complex networks of species. In this sense, ecological interactions play a dual role: ecological interactions are essential to guarantee the resilience of communities and the functioning of ecosystem services, and they are a source of selection that shapes complex traits. The development of a new integrative framework combining the complexity of selected traits with the complexity of interaction patterns is essential to address potential cascading effects and extinctions. Unfortunately, studies that focus on these two levels of complexity, whether using theoretical or empirical approaches, are still scarce. In this special feature, we bring together articles that contribute to bridging this gap in the study of species coevolution and the evolution of complex traits.


Asunto(s)
Ecosistema , Selección Genética , Evolución Biológica , Biota , Cambio Climático
4.
PLoS One ; 12(1): e0170638, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28122006

RESUMEN

The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (<1 km2), because larval input of reef organisms is largely decoupled from local adult reproduction. We examined the structure of fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5-0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3-6 times greater, and macroalgal browsing was 3-5 times greater in MPAs than in non-MPAs. On average, MPAs had 260-280% as much coral cover and only 5-25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs.


Asunto(s)
Antozoos , Conservación de los Recursos Naturales/métodos , Arrecifes de Coral , Peces , Animales , Ecosistema , Fiji
5.
PLoS One ; 6(2): e17395, 2011 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-21386981

RESUMEN

Mutualistic networks are crucial to the maintenance of ecosystem services. Unfortunately, what we know about seed dispersal networks is based only on bird-fruit interactions. Therefore, we aimed at filling part of this gap by investigating bat-fruit networks. It is known from population studies that: (i) some bat species depend more on fruits than others, and (ii) that some specialized frugivorous bats prefer particular plant genera. We tested whether those preferences affected the structure and robustness of the whole network and the functional roles of species. Nine bat-fruit datasets from the literature were analyzed and all networks showed lower complementary specialization (H(2)' = 0.37±0.10, mean ± SD) and similar nestedness (NODF = 0.56±0.12) than pollination networks. All networks were modular (M = 0.32±0.07), and had on average four cohesive subgroups (modules) of tightly connected bats and plants. The composition of those modules followed the genus-genus associations observed at population level (Artibeus-Ficus, Carollia-Piper, and Sturnira-Solanum), although a few of those plant genera were dispersed also by other bats. Bat-fruit networks showed high robustness to simulated cumulative removals of both bats (R = 0.55±0.10) and plants (R = 0.68±0.09). Primary frugivores interacted with a larger proportion of the plants available and also occupied more central positions; furthermore, their extinction caused larger changes in network structure. We conclude that bat-fruit networks are highly cohesive and robust mutualistic systems, in which redundancy is high within modules, although modules are complementary to each other. Dietary specialization seems to be an important structuring factor that affects the topology, the guild structure and functional roles in bat-fruit networks.


Asunto(s)
Quirópteros/fisiología , Ecosistema , Cadena Alimentaria , Frutas/fisiología , Dispersión de Semillas/fisiología , Adaptación Biológica/fisiología , Animales , Análisis por Conglomerados , Conducta Alimentaria/fisiología , Polinización/fisiología , Especificidad de la Especie
6.
J Chem Ecol ; 29(5): 1065-72, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12857021

RESUMEN

Quinolizidine alkaloids (QAs) are secondary compounds found in seeds of many species of plants, possibly protecting them against pathogens and seed predators. QAs were isolated from Ormosia arborea seeds and bioassayed against red-rumped agoutis (Dasyprocta leporina, Rodentia: Caviomorpha) to verify if they inhibit seed predation and food hoarding (seed dispersal). Three treatments were used: (1) seeds of O. arborea, (2) palatable seeds of Mimusops coriacea (Sapotaceae) treated with MeOH, and (3) seeds of M. coriacea treated with QAs dissolved in MeOH in similar concentration to that present in O. arborea. Palatable seeds were significantly more preyed upon than seeds treated with QAs and Ormosia seeds, but QAs did not influence hoarding behavior. QAs in O. arborea may have a strong effect in avoiding seed predation by rodents, without reducing dispersal.


Asunto(s)
Alcaloides/farmacología , Fabaceae/química , Conducta Alimentaria , Quinolizinas/farmacología , Roedores , Adaptación Fisiológica , Animales , Dinámica Poblacional , Semillas/química
7.
Rev. bras. saúde ocup ; 25(95/96): 9-18, abr. 1999. ilus, tab
Artículo en Portugués | LILACS | ID: lil-251786

RESUMEN

Os efeitos do sedentarismo sao os principais causadores de problemas posturais. Este estudo teve por objetivo verificar a existencia de correlacoes significativas mediante 14 variaveis, que estudaram os desvios posturais, por meio de demarcacoes em pontos anatomicos no corpo humano. Foram selecionados 42 individuos sendo 40 homens e 02 mulheres, trabalhadores do setor de marcenaria - Unicamp...


Asunto(s)
Humanos , Masculino , Femenino , Actividad Motora , Postura , Anatomía , Restricción Física
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