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1.
J Vis Exp ; (160)2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32628163

RESUMO

Studies of the gut microbiota contribution to the host physiology and immunocompetence are facilitated by the availability of germ-free animal models, which are considered the gold standard. Nesting birds are ideal models for the production of germ-free animals since there is no need to raise their relatives under sterile conditions. Germ-free chickens are mainly generated from specific-pathogen-free (SPF) experimental lines, which are poorly representative of commercial chicken lines. The method proposed here allowed the production of germ-free chickens from the fast growing broiler line Ross PM3, commonly used by the poultry industry. Eggs were quickly collected after laying at a broiler breeder farm. They underwent a strict decontamination process from the collection to the introduction in a sterile egg hatching isolator. The chicks have been hatched and kept in these sterile isolators during the period necessary to control their sterility. Originally developed for an experimental SPF white leghorn line, the present protocol has been adapted not only to the Ross PM3 broiler line but also to quails. It therefore represents a robust and readily adaptable procedure to other poultry species and nesting birds of economic, biological or ecological relevance.


Assuntos
Galinhas/crescimento & desenvolvimento , Galinhas/microbiologia , Microbiota , Organismos Livres de Patógenos Específicos , Animais , Óvulo/fisiologia
2.
PLoS One ; 15(7): e0236489, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726365

RESUMO

Ground-nesting birds face many challenges to reproduce successfully, with nest predation being the main cause of reproductive failure. Visual predators such as corvids and egg-eating raptors, are among the most common causes of nest failure; thus, parental strategies that reduce the risk of visual nest predation should be favored by selection. To date, most research has focused on egg crypsis without considering adult crypsis, although in natural circumstances the eggs are covered by an incubating parent most of the time. Here we use a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus) as model species to experimentally test whether decoy parents influence nest predation. Using artificial nests with a male decoy, a female decoy or no decoy, we found that the presence of a decoy increased nest predation (N = 107 nests, p < 0.001). However, no difference was found in predation rates between nests with a male versus female decoy (p > 0.05). Additionally, we found that nests in densely vegetated habitats experienced higher survival compared to nests placed in sparsely vegetated habitats. Nest camera images, predator tracks and marks left on eggs identified the brown-necked raven (Corvus ruficollis) as the main visual nest predator. Our study suggests that the presence of incubating parents may enhance nest detectability to visual predators. However, parents may reduce the predation risk by placing a nest in sites where they are covered by vegetation. Our findings highlight the importance of nest site selection not only regarding egg crypsis but also considering incubating adult camouflage.


Assuntos
Aves/fisiologia , Comportamento de Nidação/fisiologia , Reprodução/fisiologia , Animais , Ecossistema , Feminino , Óvulo/fisiologia , Densidade Demográfica , Comportamento Predatório/fisiologia , Cimentos de Resina/química
3.
Proc Natl Acad Sci U S A ; 117(31): 18302-18309, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690677

RESUMO

The ability to evaluate sperm at the microscopic level, at high-throughput, would be useful for assisted reproductive technologies (ARTs), as it can allow specific selection of sperm cells for in vitro fertilization (IVF). The tradeoff between intrinsic imaging and external contrast agents is particularly acute in reproductive medicine. The use of fluorescence labels has enabled new cell-sorting strategies and given new insights into developmental biology. Nevertheless, using extrinsic contrast agents is often too invasive for routine clinical operation. Raising questions about cell viability, especially for single-cell selection, clinicians prefer intrinsic contrast in the form of phase-contrast, differential-interference contrast, or Hoffman modulation contrast. While such instruments are nondestructive, the resulting image suffers from a lack of specificity. In this work, we provide a template to circumvent the tradeoff between cell viability and specificity by combining high-sensitivity phase imaging with deep learning. In order to introduce specificity to label-free images, we trained a deep-convolutional neural network to perform semantic segmentation on quantitative phase maps. This approach, a form of phase imaging with computational specificity (PICS), allowed us to efficiently analyze thousands of sperm cells and identify correlations between dry-mass content and artificial-reproduction outcomes. Specifically, we found that the dry-mass content ratios between the head, midpiece, and tail of the cells can predict the percentages of success for zygote cleavage and embryo blastocyst formation.


Assuntos
Doenças dos Bovinos/diagnóstico , Processamento de Imagem Assistida por Computador/métodos , Infertilidade Masculina/veterinária , Redes Neurais de Computação , Espermatozoides/ultraestrutura , Animais , Bovinos , Feminino , Infertilidade Masculina/diagnóstico , Masculino , Folículo Ovariano , Óvulo/fisiologia , Análise do Sêmen
4.
J Insect Sci ; 20(3)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32478839

RESUMO

The spotted wing drosophila, Drosophila suzukii Matsumura, which is widely spread in the main soft-skinned fruits production areas in China, presents a threat to importing countries. In order to develop a phytosanitary cold treatment measure for preventing the movement of this drosophila fly, cold tolerance of six immature life stages of D. suzukii was compared followed by time-mortality and large-scale confirmatory tests on the most tolerant stage in grape fruit. Egg was defined as the most cold-tolerant stage by comparing the mortality of all the immature stages (egg, first, second, and third instars, early and late pupa) treated at 0 and 2°C. The minimal lethal time (LT) for 99.9968% mortality (95% confidence level [CL]) estimated by the probit model was 10.47 d at 0°C and 11.92 d at 2°C, respectively. Hence, 11 d (at 0°C) and 12 d (at 2°C) were chosen as the target time to conduct the confirmatory tests. No survivors were found among the estimated 50,385 and 57,366 treated eggs, which resulted in the efficacy of 99.9941 and 99.9948% mortality (95% CL) at 0 and 2°C, respectively. Our study suggests a technical basis for cold disinfestation on D. suzukii in cage-infested Chinese 'Red Globe' (Vitis vinifera L.) grape, which could provide flexible phytosanitary treatment for control of D. suzukii in the international trade of grape.


Assuntos
Temperatura Baixa , Drosophila/fisiologia , Frutas , Controle de Insetos/métodos , Vitis , Animais , China , Drosophila/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Pupa/crescimento & desenvolvimento , Pupa/fisiologia
5.
J Vet Sci ; 21(3): e41, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32476315

RESUMO

BACKGROUND: The poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method. OBJECTIVES: The aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method. METHODS: We compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings. RESULTS: The statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites. CONCLUSIONS: This method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Infestações por Ácaros/veterinária , Ácaros/fisiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Larva/crescimento & desenvolvimento , Larva/fisiologia , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/parasitologia , Ácaros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Óvulo/fisiologia , Doenças das Aves Domésticas/parasitologia , República da Coreia/epidemiologia
6.
PLoS One ; 15(5): e0232737, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32392234

RESUMO

The oceanographic conditions of the Pacific Ocean are largely modified by El Niño (EN), affecting several ecological processes. Parasites and other marine organisms respond to environmental variation, but the influence of the EN cycle on the seasonal variation of parasitic copepods has not been yet evaluated. We analysed the relation between infection parameters (prevalence and mean intensity) of the widespread parasitic copepods Caligus bonito and Charopinopsis quaternia in the dolphinfish Coryphaena hippurus and oceanography during the strong 2015-16 EN. Fish were collected from capture fisheries on the Ecuadorian coast (Tropical Eastern Pacific) over a 2-year period. Variations of sea surface temperature (SST), salinity, chlorophyll a (Chl-a), Oceanic Niño Index (ONI), total host length (TL) and monthly infection parameters of both copepod species were analysed using time series and cross-correlations. We used the generalised additive models for determine the relationship between environmental variables and infection parameters. The total body length of the ovigerous females and the length of the eggs of C. bonito were measured in both periods. Infection parameters of both C. bonito and Ch. quaternia showed seasonal and annual patterns associated with the variation of environmental variables examined (SST, salinity, Chl-a and ONI 1+2). Infection parameters of both copepod species were significantly correlated with ONI 1+2, SST, TL and Chl-a throughout the GAMLSS model, and the explained deviance contribution ranged from 16%-36%. Our results suggest than an anomaly higher than +0.5°C triggers a risen in infection parameters of both parasitic copepods. This risen could be related to increases in egg length, female numbers and the total length of the ovigerous females in EN period. This study provides the first evidence showing that tropical parasitic copepods are sensitive to the influence of EN event, especially from SST variations. The observed behaviour of parasitic copepods likely affects the host populations and structure of the marine ecosystem at different scales.


Assuntos
Copépodes/fisiologia , El Niño Oscilação Sul , Infecções/epidemiologia , Infecções/parasitologia , Perciformes/parasitologia , Clima Tropical , Animais , Feminino , Modelos Biológicos , Óvulo/fisiologia , Oceano Pacífico , Prevalência , Fatores de Tempo
7.
PLoS Negl Trop Dis ; 14(5): e0007640, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32442168

RESUMO

We present a comprehensive analysis of the hepatic miRNA transcriptome at one month post-infection of experimental primary alveolar echinococcosis (AE), a parasitic infection caused upon ingestion of E. multilocularis eggs. Liver tissues were collected from infected and non-infected C57BL/6 mice, then small RNA libraries were prepared for next-generation sequencing (NGS). We conducted a Stem-loop RT-qPCR for validation of most dysregulated miRNAs. In infected mice, the expression levels of 28 miRNAs were significantly altered. Of these, 9 were up-regulated (fold change (FC) ≥ 1.5) and 19 were down-regulated (FC ≤ 0.66) as compared to the non-infected controls. In infected livers, mmu-miR-148a-3p and mmu-miR-101b-3p were 8- and 6-fold down-regulated, respectively, and the expression of mmu-miR-22-3p was reduced by 50%, compared to non-infected liver tissue. Conversely, significantly higher hepatic levels were noted for Mus musculus (mmu)-miR-21a-5p (FC = 2.3) and mmu-miR-122-5p (FC = 1.8). In addition, the relative mRNA expression levels of five genes (vegfa, mtor, hif1-α, fasn and acsl1) that were identified as targets of down-regulated miRNAs were significantly enhanced. All the five genes exhibited a higher expression level in livers of E. multilocularis infected mice compared to non-infected mice. Finally, we studied the issue related to functionally mature arm selection preference (5p and/or 3p) from the miRNA precursor and showed that 9 pre-miRNAs exhibited different arm selection preferences in normal versus infected liver tissues. In conclusion, this study provides first evidence that miRNAs are regulated early in primary murine AE. Our findings raise intriguing questions such as (i) how E. multilocularis affects hepatic miRNA expression;(ii) what are the alterations in miRNA expression patterns in more advanced AE-stages; and (iii) which hepatic cellular, metabolic and/or immunologic processes are modulated through altered miRNAs in AE. Thus, further research on the regulation of miRNAs during AE is needed, since miRNAs constitute an attractive potential option for development of novel therapeutic approaches against AE.


Assuntos
Equinococose/genética , Echinococcus multilocularis/fisiologia , Fígado/metabolismo , MicroRNAs/metabolismo , Óvulo/crescimento & desenvolvimento , Animais , Equinococose/metabolismo , Equinococose/parasitologia , Echinococcus multilocularis/crescimento & desenvolvimento , Feminino , Humanos , Fígado/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Óvulo/fisiologia
8.
Poult Sci ; 99(5): 2624-2632, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359598

RESUMO

Three experiments were conducted to determine the effect of different dietary net energy (NE) and AMEn ratios (NE:AMEn) on performance, egg quality, and heat production (HP) in laying hens. In experiment 1, 62 Hy-Line Brown hens were fed 2 treatments with 31 replicates from 44 to 54 wk of age. In experiment 2, 600 hens of the same strain were fed 3 treatments from 22 to 42 wk of age with 10 replicates. Both used a completely randomized design. Diets were based on corn, wheat, wheat bran, barley, soybean meal, canola meal, meat and bone meal, and canola oil. In both experiments, the NE:AMEn ratio of diets was increased with higher oil inclusion compared with T1 controls. The AMEn (kcal/kg), NE (kcal/kg), ether extract (g/kg), and CP (g/kg), respectively, on a DM basis in experiment 1 was T1: 3,011, 2,288, 42, 202 and T2: 3,023, 2,374, 81, 203; and in experiment 2, T1: 3,026, 2,324, 25, 187; T2: 2,949, 2,315, 61, 185; and T3: 3,026, 2,397, 73, 181. Increasing the ratio of NE:AMEn decreased feed intake (P < 0.001) and increased egg mass (P < 0.05) in experiment 2 and increased egg weight (P < 0.01), decreased feed conversion ratio (P < 0.01), increased egg albumen % (P < 0.001), and decreased yolk % (P < 0.05) and shell % (P < 0.05) compared with T1 controls in both experiments. Haugh units and yolk color scores were increased with high NE:AMEn in both experiments (P < 0.001; P < 0.01). Experiment 3 was conducted in calorimetry chambers to measure HP in birds fed experiment 2 diets. Increasing the NE:AMEn increased total retained energy (RE), RE as fat, and RE in the body (kcal/kg BW0.75/D) and NE:AME. The results indicate that using oil to increase the NE:AMEn results in improved performance and egg quality and more efficient energy utilization.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas/fisiologia , Dieta/veterinária , Metabolismo Energético , Óvulo/fisiologia , Termogênese , Animais , Calorimetria/veterinária , Feminino
9.
Poult Sci ; 99(5): 2727-2735, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359610

RESUMO

In this study, the aim was to investigate effects of chronic heat stress (CHS) on the mRNA levels of proinflammatory cytokines (interleukin [IL]-6, IL-8, IL-1ß, and tumor necrosis factor alpha [TNF-α]), toll-like receptors (TLR2 and TLR4), heat shock proteins (Hsp70, heat shock transcription factor [HSF]-1, and HSF3) and antioxidant enzymes (catalase, glutathione peroxidase, NADPH oxidase, and superoxide-dismutase) in the jejunal mucosae of broiler chickens subjected to thermal manipulation (TM) during embryogenesis. TM was carried out at 39°C and 65% relative humidity (RH) for 18 h daily from embryonic days 10 to 18. Control group was incubated at 37.8°C and 56% RH. CHS was induced by raising the temperature to 35°C for 7 D throughout posthatch days 28 to 35. On post-hatch-day 28 (day zero of CHS) and after 1, 3, 5, and 7 D of CHS, the jejunal mucosae were collected from both groups to evaluate the mRNA levels by real-time reverse transcription-PCR analysis. On day zero of CHS, the mRNA levels of antioxidant enzymes, TLRs, HSF3, IL-1ß, and TNF-α were not significantly different between TM and control groups, while the levels of IL-6, IL-8, and HSF1 were lower and the level of Hsp70 was higher in TM. However, during CHS, the mRNA levels of antioxidant enzymes, IL-1ß, TNF-α, TLR4, and HSF1 were significantly lower in TM than in controls, while the levels of TLR2 and IL-8 were significantly higher in TM than in controls. In addition, TM led to significant increase of mRNA levels of IL-6 and HSF3 after 1 D and Hsp70 after 3 D of CHS and to significant decrease of mRNA levels of IL-6 after 3 and 5 D, HSF3 after 7 D, and Hsp70 after 5 D of CHS. Results of this study suggest that TM led to altered posthatch antioxidant, immunological, and Hsp response to CHS in the jejunal mucosae of broiler chickens, probably indicating that TM may mitigate the adverse effects of CHS.


Assuntos
Proteínas Aviárias/genética , Galinhas/fisiologia , Resposta ao Choque Térmico/fisiologia , Óvulo/fisiologia , RNA Mensageiro/genética , Animais , Proteínas Aviárias/metabolismo , Embrião de Galinha/fisiologia , Feminino , Temperatura Alta/efeitos adversos , Mucosa Intestinal/fisiologia , Jejuno/fisiologia , RNA Mensageiro/metabolismo
10.
Sci Rep ; 10(1): 4224, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273522

RESUMO

Dinosaur embryos are among the rarest of fossils, yet they provide a unique window into the palaeobiology of these animals. Estimating the developmental stage of dinosaur embryos is hindered by the lack of a quantitative method for age determination, by the scarcity of material, and by the difficulty in visualizing that material. Here we present the results of a broad inquiry, using 3D reconstructions from X-ray computed tomography data, into cranial ossification sequences in extant saurian taxa and in well-preserved embryos of the early branching sauropodomorph dinosaur Massospondylus carinatus. Our findings support deep-time conservation of cranial ossification sequences in saurians including dinosaurs, allowing us to develop a new method for estimating the relative developmental percentage of embryos from that clade. We also observe null-generation teeth in the Massospondylus carinatus embryos which get resorbed or shed before hatching, similar to those of geckos. These lines of evidence allow us to confidently estimate that the Massospondylus carinatus embryos are only approximately 60% through their incubation period, much younger than previously hypothesized. The overall consistency of our results with those of living saurians indicates that they can be generalized to other extinct members of that lineage, and therefore our method provides an independent means of assessing the developmental stage of extinct, in-ovo saurians.


Assuntos
Evolução Biológica , Dinossauros/embriologia , Dinossauros/fisiologia , Osteogênese , Óvulo/fisiologia , Crânio/embriologia , Crânio/fisiologia , Animais , Dinossauros/anatomia & histologia , Fósseis , Filogenia
11.
Parasit Vectors ; 13(1): 178, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32264941

RESUMO

BACKGROUND: Aedes aegypti is a potential vector for several arboviruses including dengue and Zika viruses. The species seems to be restricted to subtropical/tropical habitats and has difficulties in establishing permanent populations in southern Europe, probably due to constraints during the winter season. The aim of this study was to systematically analyze the cold tolerance (CT) of Ae. aegypti in its most cold-resistant life stage, the eggs. METHODS: The CT of Ae. aegypti eggs was compared with that of Ae. albopictus which is well established in large parts of Europe. By systematically studying the literature (meta-analysis), we recognized that CT has been rarely tested in Ae. aegypti eggs, but eggs can survive at zero and sub-zero temperatures for certain exposure periods. To overcome potential bias from experimental differences between studies, we then conducted species comparisons using a harmonized high-resolution CT measuring method. From subtropical populations of the same origin, the survival (hatching in %) and emergence of adults of both species were measured after zero and sub-zero temperature exposures for up to 9 days (3 °C, 0 °C and - 2 °C: ≤ 9 days; - 6 °C: ≤ 2 days). RESULTS: Our data show that Ae. aegypti eggs can survive low and sub-zero temperatures for a short time period similar to or even better than those of Ae. albopictus. Moreover, after short sub-zero exposures of eggs of both species, individuals still developed into viable adults (Ae. aegypti: 3 adults emerged after 6 days at - 2 °C, Ae. albopictus: 1 adult emerged after 1 day at - 6 °C). CONCLUSIONS: Thus, both the literature and the present experimental data indicate that a cold winter may not be the preventing factor for the re-establishment of the dengue vector Ae. aegypti in southern Europe.


Assuntos
Aedes/fisiologia , Comportamento Animal , Temperatura Baixa , Estações do Ano , Animais , Europa (Continente) , Feminino , Larva/fisiologia , Mosquitos Vetores/fisiologia , Óvulo/fisiologia
12.
Sci Rep ; 10(1): 6418, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286472

RESUMO

Bactrocera tau (Walker) (Diptera: Tephritidae) is an economically important invasive pest, that is capable of seriously reducing the quality and yield of vegetables and fruits, it was first recorded from Fujian province in 1849 and later introduced to Yunnan province in 1912 as a result in trade fruits and vegetables of China. In recent years, with the onset of global climate change and the accompanying increase in the greenhouse effect, elevated climatic temperatures have become one of the main environmental factors affecting growth and reproduction in insects, and the optimal developmental temperature of B. tau was found to be from 25 °C to 31 °C, the growth, development and reproduction of B. tau are normal under the optimal temperature conditions. In order to determine the repercussions that elevated temperature have on B. tau, we assessed the effects that short-term (12 h) high-temperature exposures (34 °C, 36 °C, 38 °C, 40 °C, 42 °C, 44 °C, 46 °C, and 48 °C) had on the growth, development and reproduction of B. tau at different developmental stages of the fly. The results showed that the survival rate of B. tau gradually decreased in all stages following exposure to short-term high-temperatures. The pupal stage was the least sensitive to increased temperatures. The pupae withstood the highest lethal temperature, having an LT50 of 42.060 °C, followed by female adults (40.447 °C), male adults (40.013 °C), and larvae (36.740 °C). The egg stage, which was the most susceptible to heat increases, had the lowest LT50 (38.310 °C). No significant effects were observed in the developmental stages of B. tau at temperatures from 24 °C to 38 °C. The development duration was significantly prolonged at 40 °C (P < 0.05) in the eggs (2.830d), larvae (7.330d), and pupae (8.170d) (P < 0.05). B. tau was unable to survive at temperatures above 42 °C. The pre-oviposition of female adults was extended, the average egg number per female showed a downward trend, the longevity of adults gradually shortened, and the ratio of female to male offspring increased as temperature increments were increased. In summary, short-term high-temperatures over 42 °C were not suitable for successful development of B. tau, while short-term high-temperatures over 40 °C were not suitable for successful reproduction in B. tau.


Assuntos
Temperatura Alta , Tephritidae/crescimento & desenvolvimento , Tephritidae/fisiologia , Animais , Feminino , Larva/crescimento & desenvolvimento , Longevidade , Masculino , Oviposição/fisiologia , Óvulo/fisiologia , Pupa/crescimento & desenvolvimento , Reprodução/fisiologia , Análise de Sobrevida , Fatores de Tempo
13.
Poult Sci ; 99(4): 2001-2006, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241483

RESUMO

The aim of this study was to evaluate an ethanolic extract of propolis and clove essential oil as a substitute for paraformaldehyde for the sanitation of fertile eggs. In total, 1,800 hatching eggs (from 40-week-old CPK [Pesadão Vermelho] breeder hens) were randomly distributed among the treatments (grain alcohol, clove essential oil, ethanolic extract of propolis, and paraformaldehyde). Spraying was the application method for all treatments except for paraformaldehyde, for which fumigation was used. The experimental design was a randomized block design with 4 treatments. Analysis of the incubation parameters was based on 6 replications per treatment. The egg weight loss was lower in the eggs treated with ethanolic extract of propolis (8.59 ± 3.34%) than in the eggs treated with grain alcohol (13.40 ± 2.87%), clove essential oil (12.96 ± 3.33%), and paraformaldehyde (13.05 ± 3.24%). The hatchability of the fertile eggs (51.39 ± 5.81%) and the hatchability of the set eggs (44.74 ± 6.79%) were negatively affected by the application of ethanolic extract of propolis. Late mortality of eggs treated was higher than early mortality in the grain alcohol (12.14 ± 4.72%; 2.86 ± 3.30%), clove essential oil (4.60 ± 5.95%; 3.03 ± 3.50%), and ethanolic extract of propolis (36.63 ± 6.60%, 11.98 ± 4.30%) treatments. The eggs treated with clove essential oil (67.90 ± 1.87%), paraformaldehyde (67.80 ± 1.85%), or grain alcohol (67.50 ± 1.92%) presented chick yields as expected. However, despite the ideal yield of eggs treated with ethanolic extract of propolis (69.25 ± 1.68%), its application at the concentration used in the present research is not recommended. Clove essential oil, when sprayed on fertile eggs as a sanitizing agent, did not differ from paraformaldehyde in relation to hatchery performance parameters.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Galinhas/fisiologia , Óleo de Cravo/uso terapêutico , Formaldeído/uso terapêutico , Óvulo/fisiologia , Polímeros/uso terapêutico , Própole/uso terapêutico , Animais , Distribuição Aleatória
14.
Poult Sci ; 99(4): 2007-2010, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241484

RESUMO

Egg production on a flock level can be summarized into several phases determined by biology of individual birds: rapid increase in production reflecting achieving sexual maturity, peak production related to maximum laying potential, followed by gradual decrease in the rate of lay as the birds age. In 1989 Yang et al. proposed a mathematical model (modified compartmental model) to describe this process. In this study a biphasic modified compartmental model was proposed for modeling, classifying, and predicting egg production in single cycle and molted flocks. Goodness-of-fit was high for both single cycle (average R2 = 0.99) and molted flocks (average R2 = 0.97), suggesting that the model could be used for benchmarking molted flocks. The difference in R2 between the biphasic model and the model used by Yang et al in 1989 can be used to differentiate between single cycle and molted flocks. The biphasic model was shown to predict future records well up to 8 wk in advance, but as with any regression model, caution is recommended when predicting records outside of the observed age range.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas/fisiologia , Óvulo/fisiologia , Reprodução , Animais , Feminino , Modelos Biológicos , Muda
15.
Poult Sci ; 99(4): 2100-2107, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241495

RESUMO

The present study was conducted to evaluate the effects of dietary marine-derived polysaccharides (MDP) from seaweed Enteromorpha on productive performance, egg quality, antioxidant capacity, and jejunal morphology in late-phase laying hens. A total of 240 Lohmann white laying hens (62 wk of age) were assigned to 4 dietary treatments that included MDP at concentrations of 0, 1,000, 2,500, and 5,000 mg/kg for 6 wk. Each treatment had 6 replicates with 5 cages (2 birds/cage). The results showed that dietary MDP quadratically improved egg production (P < 0.05) during 5 to 6 wk and 1 to 6 wk. There was a linear reduction in cracked egg rate (P < 0.05) with dietary MDP levels increased during 3 to 4 wk and 1 to 6 wk. After 4 wk of feeding trial, the egg shell thickness, yolk color, and Haugh unit showed a linear increase (P < 0.05) in response to increasing dietary MDP levels. Besides, the egg shell breaking strength, egg shell thickness, yolk color, and Haugh unit were improved linearly (P < 0.05) by dietary MDP at the end of the experiment. Moreover, dietary MDP showed a linear and quadratic reduction in serum malondialdehyde (MDA) content (P < 0.05) at the end of third week. At the end of experiment, the activity of total superoxide dismutase in serum was increased quadratically (P < 0.05) by dietary MDP, and dietary MDP quadratically improved the liver catalase (CAT) activity (P < 0.05) and linearly enhanced jejunal CAT activity (P < 0.05), whereas linearly decreased jejunal MDA concentration (P < 0.05). Furthermore, supplemental MDP linearly improved the villus height (P < 0.05) and quadratically increased villus height/crypt depth ratio (P < 0.05) of jejunum. However, dietary MDP had no effect on jejunal trypsin, amylase, and protease activity (P > 0.10). Taken together, these findings provided new insights into the role of MDP in improving the productive performance, egg quality, antioxidant capacity, and jejunal morphology of late-phase laying hens.


Assuntos
Antioxidantes/metabolismo , Galinhas/fisiologia , Clorófitas/química , Carboidratos da Dieta/metabolismo , Jejuno/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Polissacarídeos/metabolismo , Ração Animal/análise , Animais , Galinhas/anatomia & histologia , Dieta/veterinária , Carboidratos da Dieta/administração & dosagem , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Feminino , Jejuno/anatomia & histologia , Óvulo/fisiologia , Polissacarídeos/administração & dosagem , Distribuição Aleatória
16.
Poult Sci ; 99(4): 2256-2265, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241511

RESUMO

The aim of this study was to determine the effect of addition of alfalfa protein concentrate (APC) at the dose of 15 g or 30 g per 1 kg of complete feed ration for the native Polbar breed on selected production traits and the fatty acid profile in the yolk of raw, hard-boiled or freeze-dried eggs. Laying hens were assigned randomly to 3 experimental groups, each comprising 30 birds. The control group received a standard diet without the APC addition and the experimental groups received APC, which partially replaced postextraction soybean meal. Egg laying performance, feed intake, and feed conversion ratio were controlled throughout the experiment. At 33 wk of age, 45 eggs were randomly selected for assessment of the quality of the egg content and eggshell, and 30 eggs were taken for each of the cooking and freeze-drying treatments. The fatty acid composition was determined in the yolks of hard-boiled, freeze-dried, and raw eggs. There was no effect of the APC addition on the laying performance, feed intake and feed conversion ratio, and a majority of egg quality traits. Hens fed with the APC laid eggs with a darker colored eggshell and yolk and a slightly lower breaking strength. The yolks in the eggs from hens receiving the APC addition were characterized by distinctly higher content of polyunsaturated fatty acids (PUFA). The group fed with a higher dose of APC produced eggs with a substantially lower level of saturated fatty acids (SFA). Boiling resulted in an increase in the SFA content and a decline in the level of PUFAs and carotenoids. Freeze-drying led to an increase in the total SFA content and a decrease in the level of n-3 PUFA. The APC addition to feed can replace the genetically modified soybean meal without reducing the values of production traits and egg quality and with a beneficial effect on the yolk color and fatty acid profile.


Assuntos
Carotenoides/análise , Galinhas/fisiologia , Ovos/análise , Ácidos Graxos/análise , Manipulação de Alimentos/métodos , Óvulo/fisiologia , Proteínas de Vegetais Comestíveis/metabolismo , Ração Animal/análise , Animais , Culinária , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Gema de Ovo/química , Feminino , Liofilização , Medicago sativa/química , Proteínas de Vegetais Comestíveis/administração & dosagem , Distribuição Aleatória
17.
Poult Sci ; 99(4): 2275-2285, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241513

RESUMO

This study was conducted to determine the effect of probiotic Pediococcus acidilactici (PA) strain MA18/5M supplementation of diets with different dietary energy levels on productive performance, egg quality, and body composition in Hy-Line Brown hens during a 16-week period from 32 to 47 wk of age. The experimental treatments with a 2 × 2 factorial design received a 2 wheat-corn-soybean diet: a moderately low energy density diet with 2,650 kcal ME/kg (M-LED) and a low energy density diet based on the M-LED diet with 2,550 kcal ME/kg (LED), each diet without and with probiotic supplementation (M-LED, LED, M-LEDp, and LEDp, respectively). Reduced dietary energy levels had a particularly negative effect on egg weight (61.7 vs. 63.3 g; -2.6%, P < 0.001), egg mass output (1.67 vs. 1.71 kg; -2.4%, P = 0.015), and FCR (2.01 vs. 1.97 kg feed/kg egg; +2%, P = 0.028). In hens administered the LED diet, deteriorated productive performance was accompanied by greater body weight loss (P < 0.001) and reduced abdominal fat content (P < 0.033) as compared with the M-LED group. Dietary probiotic inclusion increased egg weight (P = 0.015), including relative eggshell weight (P = 0.008) and eggshell thickness (P = 0.002) and significantly improved FCR (P = 0.010). No interactions between the PA-based probiotic and dietary energy levels were found in any of the tested parameters. Adding the probiotic on top of the M-LED diet improved layers performance but resulted in nonbioequivalence for the egg weight, egg mass output, and FCR compared with this group without probiotic. Probiotic supplementation of the LEDp diet improved all performance parameters except for egg weight. As a result, the laying rate, egg mass output, daily feed intake, and FCR in the LEDp treatment were bioequivalent to those noted in the M-LED group without the probiotic. The results of a bioequivalence test suggest that a low energy diet fed to laying hens promoted a probiotic response to improve energy utilization by birds.


Assuntos
Composição Corporal/efeitos dos fármacos , Galinhas/fisiologia , Óvulo/efeitos dos fármacos , Pediococcus acidilactici/química , Probióticos/farmacologia , Ração Animal/análise , Animais , Dieta/veterinária , Feminino , Óvulo/fisiologia , Probióticos/administração & dosagem
18.
Poult Sci ; 99(3): 1341-1348, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111310

RESUMO

The aim of this study was to compare egg quality, carcass, meat characteristics, and bone properties of Taihang chickens in 2 different housing systems at various ages. A total of 168 birds were selected and randomly allocated to 2 groups at 23 wks and raised in conventional cage (CC) or flattening on floor (FF) housing system, respectively. FF hens' egg weight, albumen height, and Haugh unit were higher (P < 0.05), and yolk weight was lower (P < 0.001) than those of the CC hens. Egg quantity of FF hens was higher than that of the CC hens (P < 0.01). The FF hens' weight (P < 0.05) and breast meat percent (P < 0.01) were higher than those of the CC hens. The highest live body and carcass weight were observed at 57 wk (both P < 0.01), whereas the highest semieviscerated percentage (P < 0.01) and meat weight of breast and thigh (P < 0.05) were shown at 49 wk. The highest eviscerated percentage and thigh meat were displayed at 41 and 32 wk, respectively (P < 0.01). For meat color, the lightness of both breast and thigh meat in the FF group was significantly reduced compared with those of the CC group (P < 0.01 and P < 0.05). FF hens' humerus weight and breaking strength (both P < 0.01) and tibia breaking strength (P < 0.05) were significantly higher than those of the CC hens. Femur breaking strength was significantly affected by hens' age (P < 0.01). Egg weight, albumen height, Haugh unit, yolk color (all P < 0.01), pH of thigh meat, semieviscerated, and eviscerated weight (all P < 0.05) were influenced by the interaction of housing system and age, whereas no change in moisture loss rate, meat color, shearing force, and bone quality was found (P > 0.05). In summary, in the 2 housing systems, hens' age and their interaction could affect slaughter performance, quality of egg, meat, and bone of Taihang chickens. In addition, the results of the present study support a theoretical basis for the development and utilization of Taihang chickens in accordance with the FF system.


Assuntos
Galinhas/fisiologia , Abrigo para Animais , Úmero/fisiologia , Carne/análise , Óvulo/fisiologia , Tíbia/fisiologia , Fatores Etários , Criação de Animais Domésticos/métodos , Animais , China , Feminino , Distribuição Aleatória
19.
Poult Sci ; 99(3): 1369-1378, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111311

RESUMO

The low uniformity in light distribution provided by conventional lighting systems installed in laying poultry can compromise the productive performance and egg quality of laying hens. Thus, the aim of the current study is to evaluate the effect of a linear lighting system with light-emitting diode (LED strip) on the productive performance and egg quality of laying hens, by comparing it to the conventional LED lamp lighting system. The study used Hy-Line Brown hens from a commercial production unit. Hen-day egg production (%), mortality rate (%), egg weight (g), albumen height (mm), Haugh unit, eggshell thickness, eggshell strength, and thermal-environment conditions were evaluated from the 19th to the 48th wk of age. The results have shown that LED strips were capable of improving egg production (P < 0.05) in comparison to LED lamps. Egg quality was not affected (P > 0.05) by the evaluated lighting systems throughout the experimental period. Results of the current study indicate that the homogeneous illuminance distribution provided by the linear LED strip lighting system at different cage floors improved egg production in comparison to the conventional LED lamp lighting system.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas/fisiologia , Iluminação , Óvulo/fisiologia , Animais , Casca de Ovo/fisiologia , Feminino
20.
Poult Sci ; 99(3): 1444-1453, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111315

RESUMO

The present study evaluated production performance responses to Ile supplementation in laying hens fed low crude protein (LCP), amino acid (AA) balanced diets. A total of 179 Shaver white pullets were distributed into 30 battery cages (6 birds/cage, n = 6) and observed over the course of 27 wk in a 2-phase (20 to 27 and 28 to 46 wk of age) feeding program. Five isocaloric diets were formulated for standardized ileal digestible (SID) Lys intake of 750 and 710 mg/D in phase 1 and 2, respectively, and included a positive control with standard levels of crude protein (CP) (CON; 18 and 16% CP for phases 1 and 2), and 4 LCP diets (16 and 14% CP for phase 1 and 2, respectively) with graded levels of Ile to satisfy SID Ile:Lys ratios of 70 (Ile70), 80 (Ile80), 90 (Ile90), and 100% (Ile100). Based on analyzed dietary AA, the calculated SID Ile:Lys of LCP diets were 75, 84, 88, 99% and 66, 72, 82, 95% for phase 1 and 2, respectively. Dietary treatments significantly (P < 0.05) affected feed intake, hen-day egg production (HDEP), egg weight (EW), feed conversion ratio, and egg quality (Haugh unit) and composition (yolk to albumen). Lowering dietary CP negatively affected HDEP with a 3.3 and 1.5% reduction in phase 1 and 2, respectively, and this was restored with the addition of Ile (P < 0.001) suggesting that Ile was limiting in the LCP basal diet. Average EW was reduced in Ile100 only; however, the Ile:Lys appeared to influence egg size uniformity, with Ile90 producing a greater proportion of large (56 g ≤ EW > 63 g) eggs, suggesting that Ile may be used to manipulate EW at the expense of HDEP. Overall, the results indicated that CP in laying hen diets can be reduced by 2% units if fortified with synthetic AA (Met, Lys, Thr, Trp) + Ile, with optimal responses observed between 82 and 88% SID Ile:Lys.


Assuntos
Aminoácidos/administração & dosagem , Galinhas/fisiologia , Dieta com Restrição de Proteínas/veterinária , Isoleucina/metabolismo , Óvulo/fisiologia , Reprodução/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Proteínas na Dieta/metabolismo , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Feminino , Íleo/fisiologia , Isoleucina/administração & dosagem , Óvulo/efeitos dos fármacos , Distribuição Aleatória
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