Morphometric evaluation of Japanese quail embryos and their extraembryonic vascular networks exposed to low-frequency magnetic field with two different intensities.

Animals developed or in an embryonic stage, are constantly subjected to magnetic pollution generated by electrical and electronic devices. Several researches have used the bird embryo as an experimental model to evaluate the action of magnetic field (MF) and electromagnetic field (EMF). This study proposed to perform a morphometric evaluation in the embryos and in the blood vascular network of the yolk sac membranes (YSM) of Japanese quail (Coturnix japonica) exposed to the 60 Hz MF with two different intensities (0.16 and 0.65 mT). A total of 30 eggs were used, 10 eggs were used for each assay. Each assay formed a group (control group, group submitted to the MF of 0.16 mT and 0.65 mT). The images of the skeletonized vascular network of YSM were evaluated by two methods of fractal dimension: box-counting dimension (Dbc) and information dimension (Dinf). The embryos were evaluated by body mass, percentage cephalic length and body area. The fractal dimensions revealed no difference among groups. There were no significant differences in relation to embryonic body mass among groups. However, the embryos exposed to 0.65 mT MF presented a smaller embryonic body development (body area and percentage cephalic length). In conclusion, 0.16 mT and 0.65 mT magnetic fields were not able to generate significant effects on vasculogenesis and angiogenesis. However, the embryos exposed to 6 h of magnetic field with 0.65 mT intensity and 60 Hz frequency showed a decrease in embryonic body development.

Spirulina platensis in Japanese quail feeding alters fatty acid profiles and improves egg quality: Benefits to consumers.

The aim of this study was to investigate whether microalgae in Japanese quail feed alters performance, fatty acid profiles in the eggs and egg quality. One hundred quails were distributed in four groups and five replicates of five birds per experimental group. The treatments consisted of four levels of Spirulina platensis microalgae (0%, 5%, 10%, and 15%) in the diets. We evaluated the productive performance and chemical-physical characteristics of eggs, the oxidant/antioxidant status in egg yolks, and the fatty acid profile in the diet and egg yolks. Microalgae in the diet did not influence egg production; however, it increased the yolk index as well as the color intensity of the yolk. Saturated and polyunsaturated fatty acid levels decreased in egg yolks, and monounsaturated fatty acid levels increased in the yolks. Lipid peroxidation levels were lower and total antioxidant capacity was higher in egg yolks of quails receiving microalgae in the diet. PRACTICAL APPLICATIONS: Microalgae in quail diets improves egg quality and provides benefits to consumer health, acting as an antioxidant and immune-stimulant. Microalgae in quail diets had positive effects on egg quality. This is because it reduced levels of saturated fatty acids that are undesirable, and increased monounsaturated fatty acid levels that are beneficial to the health of consumers. Finally, antioxidants increased in egg yolks, consequently reducing lipid peroxidation.

Development and growth of digestive system organs of European and Japanese quail at 14 days post-hatch.

The objective of this study was to evaluate the development and growth of the digestive system organs, from the 11th day of incubation until the 14 d post-hatch in European and Japanese quail. On days 11, 13 and 15 of incubation at hatch and at 4, 7, 10 and 14 d post-hatch, embryos or chicks of European and Japanese quail were analyzed. After 15 d of incubation, samples from stomach and small intestine were analyzed by microscopy. European quail had significantly heavier body weight at 15 d of incubation and after 4 d post-hatch. The digestive system weight progressively increased with age and was similar between European and Japanese quail at 11, 13, and 15 d of incubation and 10 d post-hatch, while relative weight of digestive system was similar between quail type with great values at 4 d post-hatch. For relative weight of the small intestine + pancreas, the weight of the proventriculus and of the gastric ventricle increased significant by among ages analyzed in both types of quail. At hatch, proventriculus had functional secretory cells and mucosa of gastric ventricle had a thin coilin membrane. In small intestine segments, at 15 d of incubation the height of the villi was similar among duodenum, jejunum, and ileum (80 µm). Villi had elongated shape towards the intestinal lumen, covered by enterocytes and dispersed goblet cells with PAS+ and AB+ contend in all segments. The number of goblet cell/villi increased in segments until 7 to 10 d post-hatch. Duodenum increases the villi up to 14 d, while the jejunum and ileum up to 10 and 4 d, respectively. Based on our data in digestive system growth, a shorter period of post-hatch fast and specific diets to quail during first days of growth is recommended to both quail types. It is concluded that the development and growth of different organs of the digestive system up to 14 d of age was similar between European and Japanese quail.

Histamine H4 receptor as a novel therapeutic target for the treatment of Leydig-cell tumours in prepubertal boys.

Leydig-cell tumours (LCTs) are rare endocrine tumours of the testicular interstitium, with recent increased incidence. Symptoms include precocious puberty in children; and erectile dysfunction, infertility and/or gynaecomastia, in adults. So far, scientific evidence points to aromatase (CYP19) overexpression and excessive oestrogen and insulin-like growth factor (IGF) -1 production as responsible for Leydig-cell tumourigenesis. LCTs are usually benign; however, malignant LCTs respond poorly to chemo/radiotherapy, highlighting the need to identify novel targets for treatment. Herein, we investigated the potential role of the histamine receptor H4 (HRH4) as a therapeutic target for LCTs using R2C rat Leydig tumour cells, a well-documented in vitro model for Leydigioma. Also, we studied for the first time the expression of CYP19, IGF-1R, oestrogen receptor (ER) α, ERß, androgen receptor (AR) and HRH4 in human prepubertal LCTs versus normal prepubertal testes (NPTs). HRH4 agonist treatment inhibited steroidogenesis and proliferation in R2C cells and also negatively affected their pro-angiogenic capacity in vitro and in vivo, as assessed by evaluating the proliferative activity of human umbilical vein endothelial cells and by means of the quail chorioallantoic membrane assay, respectively. Moreover, E2 and IGF-1 inhibited HRH4 mRNA and protein levels. In human prepubertal LCTs, CYP19, IGF-1R, ERα and ERß were overexpressed compared with NPTs. In contrast, HRH4 staining was weak in LCTs, but moderate/strong and confined to the interstitium in NPTs. Importantly, HRH4 was absent or barely detectable in seminiferous tubules or germ cells. Overall, our results point to HRH4 as a novel therapeutic target in LCTs.

The effects of in-ovo injection of propolis on egg hatchability and starter live performance of Japanese Quails

The purpose of this study was to determine the effects of in-ovo injection of a propolis water extract on hatchability, embryonic mortality, starter live performance, and livability of Japanese quails. In total, 500 fresh hatching eggs were randomly distributed into five treatment groups of 100 eggs per treatment with four replicates of 25 eggs each. On day 14 of incubation, eggs from group 1 were not injected (control), group 2 was injected with distilled water (water), group 3 was injected with 1% propolis water extract (1% propolis), group 4 was injected with 2% propolis water extract (2% propolis), and group 5 was injected with 3% propolis water extract (3% propolis). A completely randomized design was applied, and data were analyzed using the least-square methodology. Hatchability and embryonic mortality in the 2% propolis and 3% propolis treatment groups were significantly lower compared with the control group, but no significant differences were observed between the 1% propolis and control groups. There were no significant bodyweight gain, feed intake, feed conversion ratio, or livability differences among treatments. The results of this study demonstrated that in-ovo injection of propolis water extract, especially at doses of 2% and 3% propolis, had negative effects on hatchability and embryonic mortality, but 1% propolis had no detrimental effects on hatchability or embryonic mortality. In all treatment groups, propolis did not negatively affect body weight gain, feed intake, feed conversion ratio, or livability.(AU)

Study on the morphological development of quail embryos

In this study, the SWKQ series microcomputer automatic incubator was used to study the growth and development of quail in the embryonic stage. Results showed that the embryo shape of became gradually defined as embryo aged. On day 6, the head and body of quail were clearly differentiated, the legs became longer and the wings appeared. At 7 embryo age, the entire embryo of quail was very clear, and the beak has formed. During 3 to 9 days of age, quail embryos length increased quickly, showing a linearly upward trend. At 9 day old, quail embryos length reached 2.2 cm. The regression equation of embryo length to day old was curve regression, giving as following: y=-0.464+0.325x-0.004x2, y: embryo length, x: the age of the embryo.(AU)

The effects of in-ovo injection of propolis on egg hatchability and starter live performance of Japanese Quails

The purpose of this study was to determine the effects of in-ovo injection of a propolis water extract on hatchability, embryonic mortality, starter live performance, and livability of Japanese quails. In total, 500 fresh hatching eggs were randomly distributed into five treatment groups of 100 eggs per treatment with four replicates of 25 eggs each. On day 14 of incubation, eggs from group 1 were not injected (control), group 2 was injected with distilled water (water), group 3 was injected with 1% propolis water extract (1% propolis), group 4 was injected with 2% propolis water extract (2% propolis), and group 5 was injected with 3% propolis water extract (3% propolis). A completely randomized design was applied, and data were analyzed using the least-square methodology. Hatchability and embryonic mortality in the 2% propolis and 3% propolis treatment groups were significantly lower compared with the control group, but no significant differences were observed between the 1% propolis and control groups. There were no significant bodyweight gain, feed intake, feed conversion ratio, or livability differences among treatments. The results of this study demonstrated that in-ovo injection of propolis water extract, especially at doses of 2% and 3% propolis, had negative effects on hatchability and embryonic mortality, but 1% propolis had no detrimental effects on hatchability or embryonic mortality. In all treatment groups, propolis did not negatively affect body weight gain, feed intake, feed conversion ratio, or livability.

Study on the morphological development of quail embryos

In this study, the SWKQ series microcomputer automatic incubator was used to study the growth and development of quail in the embryonic stage. Results showed that the embryo shape of became gradually defined as embryo aged. On day 6, the head and body of quail were clearly differentiated, the legs became longer and the wings appeared. At 7 embryo age, the entire embryo of quail was very clear, and the beak has formed. During 3 to 9 days of age, quail embryos length increased quickly, showing a linearly upward trend. At 9 day old, quail embryos length reached 2.2 cm. The regression equation of embryo length to day old was curve regression, giving as following: y=-0.464+0.325x-0.004x2, y: embryo length, x: the age of the embryo.

Immunohistochemical localization of estrogen receptor in the embryonic gonad of male quail embryo during gonadal differentiation / Localización inmunohistoquímica del receptor de estrógeno en la gónada embrionaria en el embrión de codorniz macho durante la diferenciación gonadal

In birds, male embryo the gonads develop bilateral testes, in which both left and right sides produce functional spermatozoa, whereas female embryo, only the left gonad develops into a functional ovary. Estrogen plays a key role in avian sex determination in both sexes by binding to the estrogen receptor (ER). Surprisingly, chicken estrogen receptor (cER) mRNA is expressed in both sexes; moreover; its expression is only expressed in the left male gonad. The present study aimed to localize ER protein in the left gonad of male quail embryo using immunohistochemistry. The 8-day-old male quail embryos whose embryonic sex distinguished by gonadal morphology were studied. Histology of the left male gonad displayed thin cortex containing 1 to 2 layers of the germinal epithelium, while testicular cords were observed in the medulla. ER-immunoreactive cells were only found in the germinal epithelium but not in the medulla. Localization of ER was detected in the nucleus and cytoplasm of the germinal epithelial cells. The number of ER-immunoreactive cells counted in upper, lateral, and lower regions of the germinal epithelium was 18.20±1.892, 17.60±1.887, and 16.20±1.290, respectively. This study shows the first evidence for expression of ER protein in the left male gonad of the avian embryo, indicating that ER plays a role in avian gonadal sex differentiation.

En las aves, la gónada embrionaria en los machos se desarrolla bilateralmente, ambos testículos producen espermatozoides funcionales, mientras que en el embrión hembra, sólo la gónada izquierda se convierte en un ovario funcional. El estrógeno juega un papel clave en la determinación del sexo aviar, en ambos sexos, mediante la unión al receptor de estrógeno (RE). Fuertemente los receptores de estrógenos de pollo (cRE) el ARNm se expresan en ambos sexos; además, su expresión sólo se produce en la gónada izquierda del macho. El objetivo fue localizar proteínas del RE en la gónada izquierda de embriones de codorniz macho mediante inmunohistoquímica. Se estudiaron embriones de codorniz machos a los 8 días de edad, cuyo sexo embrionario se distinguió por la morfología de las gónadas. La histología de la gónada izquierda estuvo representada por la corteza delgada que contiene de 1 a 2 capas del epitelio germinal, mientras que se observaron cordones testiculares en la médula. El RE se encontró en células inmunorreactivas del epitelio germinal, pero no en la médula. Se detectó la localización de RE en el núcleo y el citoplasma de las células epiteliales germinales. El número de células RE-inmunorreactivas en las regiones superior, lateral e inferior del epitelio germinal fue de 18,20±1,892, 17,60±1,887 y 16,20±1,290, respectivamente. Este estudio muestra la primera evidencia de expresión de la proteína de RE en la gónada izquierda del embrión aviar macho, lo que indica que el RE desempeña un papel en la diferenciación sexual de la gónada aviar.

Multifractal dimension and lacunarity of yolk sac vasculature after exposure to magnetic field.

Several studies have reported about the effects of magnetic fields (MFs) on vascular tissue. Extremely low frequency magnetic fields (ELF-MFs) can promote either inhibition or stimulation of vasculogenesis and angiogenesis, depending upon the intensity and time of exposure to the MF. To investigate the possible effects of ELF-MF on vascular processes, it is necessary to employ methods that allow parameterization of the vascular network. Vascular network is a structure with fractal geometry; therefore, fractal methods have been used to evaluate its morphometric complexity. Here, we used the lacunarity parameter (complementary method of fractal analysis) and multifractal analyses to investigate angiogenesis and vasculogenesis in the embryonic yolk sac membrane (YSM) of Japanese quails (Coturnix japonica) with and without exposure to an external MF of 1 mT and 60 Hz. Lacunarity results showed that the vascular density was lower for the group exposed to the magnetic field for 9 h/day. In addition, multifractal analysis showed reduced vascularization in the experimental groups (6 h/day and 9 h/day of exposure to MF). Furthermore, multifractal analysis showed difference between the groups exposed for 12 and 24 h/day. Using multifractal methods (generalized dimensions and singularity spectrum), it was possible to characterize the vascular network of the quail embryo YSM as a multifractal object, therefore proving this method to be a more appropriate application than the traditional monofractal methods.

Crescimento vascular em membrana do saco vitelínico e desenvolvimento embrionário de codornas japonesas (Coturnix japonica) expostas a campo magnético de baixa frequência / Vascular growth in yolk sac membrane and embryonic development of Japanese quail (Coturnix japonica) exposed to low frequency magnetic field

O objetivo deste trabalho foi observar a influência do campo magnético (CM) de baixa frequência na membrana do saco vitelínico (MSV) e no desenvolvimento do embrião de codornas japonesas (Coturnix japonica) em 72 horas de incubação. Ovos fertilizados foram expostos a nove horas consecutivas de CM, sendo um grupo a partir das 48 horas e o outro a partir das 63 horas de incubação. A quantificação da vascularização da MSV foi determinada pela obtenção da dimensão fractal por meio dos métodos de box-counting e de dimensão de informação, enquanto o peso corporal e o percentual de comprimento cefálico dos embriões foram utilizados como parâmetros de desenvolvimento embrionário. O CM não causou diferenças significativas na densidade vascular da MSV nem no desenvolvimento embrionário, quando comparados ao grupo controle.(AU)

The aim of this study was to observe the influence of the low frequency magnetic field (MF) on the yolk sac membrane (YSM) and embryonic development of Japanese quail (Coturnix japonica) in 72 hours of incubation. Fertilized eggs were exposed to 9 consecutive hours of MF, with a group from 48 hours and the second group from 63 hours of incubation. The evaluation of YSM vascularization was determined by the fractal dimensions obtained through box-counting method and information dimension, while body weight of the embryo and percentage of cephalic length were used as parameters for embryo development. The MF caused no significant differences in vessel density in the YSM, nor in the embryonic development considering the body weight and percentage cephalic length, when were compared to the control group.(AU)

Crescimento vascular em membrana do saco vitelínico e desenvolvimento embrionário de codornas japonesas (Coturnix japonica) expostas a campo magnético de baixa frequência / Vascular growth in yolk sac membrane and embryonic development of Japanese quail (Coturnix japonica) exposed to low frequency magnetic field

O objetivo deste trabalho foi observar a influência do campo magnético (CM) de baixa frequência na membrana do saco vitelínico (MSV) e no desenvolvimento do embrião de codornas japonesas (Coturnix japonica) em 72 horas de incubação. Ovos fertilizados foram expostos a nove horas consecutivas de CM, sendo um grupo a partir das 48 horas e o outro a partir das 63 horas de incubação. A quantificação da vascularização da MSV foi determinada pela obtenção da dimensão fractal por meio dos métodos de box-counting e de dimensão de informação, enquanto o peso corporal e o percentual de comprimento cefálico dos embriões foram utilizados como parâmetros de desenvolvimento embrionário. O CM não causou diferenças significativas na densidade vascular da MSV nem no desenvolvimento embrionário, quando comparados ao grupo controle...

The aim of this study was to observe the influence of the low frequency magnetic field (MF) on the yolk sac membrane (YSM) and embryonic development of Japanese quail (Coturnix japonica) in 72 hours of incubation. Fertilized eggs were exposed to 9 consecutive hours of MF, with a group from 48 hours and the second group from 63 hours of incubation. The evaluation of YSM vascularization was determined by the fractal dimensions obtained through box-counting method and information dimension, while body weight of the embryo and percentage of cephalic length were used as parameters for embryo development. The MF caused no significant differences in vessel density in the YSM, nor in the embryonic development considering the body weight and percentage cephalic length, when were compared to the control group...

The developmental origin of zygodactyl feet and its possible loss in the evolution of Passeriformes.

The zygodactyl orientation of toes (digits II and III pointing forwards, digits I and IV pointing backwards) evolved independently in different extant bird taxa. To understand the origin of this trait in modern birds, we investigated the development of the zygodactyl foot of the budgerigar (Psittaciformes). We compared its muscular development with that of the anisodactyl quail (Galliformes) and show that while the musculus abductor digiti IV (ABDIV) becomes strongly developed at HH36 in both species, the musculus extensor brevis digiti IV (EBDIV) degenerates and almost disappears only in the budgerigar. The asymmetric action of those muscles early in the development of the budgerigar foot causes retroversion of digit IV (dIV). Paralysed budgerigar embryos do not revert dIV and are anisodactyl. Both molecular phylogenetic analysis and palaeontological information suggest that the ancestor of passerines could have been zygodactyl. We followed the development of the zebra finch (Passeriformes) foot muscles and found that in this species, both the primordia of the ABDIV and of the EBDIV fail to develop. These data suggest that loss of asymmetric forces of muscular activity exerted on dIV, caused by the absence of the ABDIV, could have resulted in secondary anisodactyly in Passeriformes.

Effect of nano-sized bioactive glass particles on the angiogenic properties of collagen based composites.

Angiogenesis is essential for tissue regeneration and repair. A growing body of evidence shows that the use of bioactive glasses (BG) in biomaterial-based tissue engineering (TE) strategies may improve angiogenesis and induce increased vascularization in TE constructs. This work investigated the effect of adding nano-sized BG particles (n-BG) on the angiogenic properties of bovine type I collagen/n-BG composites. Nano-sized (20-30 nm) BG particles of nominally 45S5 Bioglass® composition were used to prepare composite films, which were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The in vivo angiogenic response was evaluated using the quail chorioallantoic membrane (CAM) as an model of angiogenesis. At 24 h post-implantation, 10 wt% n-BG containing collagen films stimulated angiogenesis by increasing by 41 % the number of blood vessels branch points. In contrast, composite films containing 20 wt% n-BG were found to inhibit angiogenesis. This experimental study provides the first evidence that addition of a limited concentration of n-BG (10 wt%) to collagen films induces an early angiogenic response making selected collagen/n-BG composites attractive matrices for tissue engineering and regenerative medicine.

Qualidade de ovos de codorna submetidos ou não a tratamento superficial da casca armazenados em diferentes ambientes / Quality of quail eggs submitted or no to surface treatment of the shell stored in different environments

With the aim of evaluating the quality of eggs of Japanese quail treated superficially, by immersion in mineral oil or propolis solution, simultaneous experiments were conducted in two environments, without refrigeration (Experiment 1) and with refrigeration (Experiment 2). For each experiment, were selected 360 intact eggs distributed in a completely randomized design in factorial 3 x 5 (untreated eggs; eggs immersed in propolis or eggs immersed in mineral oil, evaluated for five storage times: 7; 14; 21; 28 and 35 days), each treatment consisted of four replicates of six eggs each. The eggs had increased weight loss, decrease in specific gravity and growth the weight and the pH of the yolk, besides the reduced the pH of the albumen and their respective weight with advancing storage time in the absence of cooling (Experiment 1), whether treated or not in the shell. However, the surface treatment with mineral oil promoted protection against progressive loss of weight and decreased specific gravity, making them less intense with advancing the storage period without refrigeration. In the Experiment 2, the immersion of eggs in mineral oil promoted less weight loss, higher specific weight, greater weight of the yolk and the albumen during storage under refrigeration. The quality of quail eggs submitted of treatment superficial on shell by immersion in mineral oil is preserved for up to five weeks under different environments, with and without refrigeration.(AU)

Com o objetivo de avaliar a qualidade de ovos de codornas japonesas tratados superficialmente, através de imersão em óleo mineral ou solução de própolis, foram conduzidos experimentos simultâneos em dois ambientes, sem refrigeração (Experimento 1) e com refrigeração (Experimento 2). Para cada experimento, foram selecionados 360 ovos íntegros distribuídos em delineamento inteiramente casualizado em esquema fatorial 3 x 5 (ovos não tratados; ovos imersos em solução de própolis e ovos imersos em óleo mineral, avaliados durante cinco tempos de armazenamento: 7; 14; 21; 28 e 35 dias), cada tratamento foi composto por seis repetições de quatro ovos cada. Os ovos apresentaram aumento da perda de peso, diminuição do peso específico e aumento do peso e do pH da gema, além de redução do pH do albúmen e de seu respectivo peso com o avançar do tempo de estocagem na ausência de refrigeração (Experimento 1), independente se receberam ou não tratamento na casca. Entretanto, o tratamento superficial com óleo mineral promoveu proteção contra essa perda progressiva de peso e diminuição do peso específico, tornando-as menos intensas com o avançar do período de estocagem sem refrigeração. No Experimento 2, a imersão dos ovos em óleo mineral conferiu menor perda de peso, maior peso específico, maior peso de gema e de albúmen durante o armazenamento sob refrigeração.A qualidade de ovos de codornas submetidos a tratamento superficial da casca por imersão em óleo mineral é preservada por até cinco semanas em diferentes ambientes, sem e com refrigeração.(AU)

Qualidade de ovos de codorna submetidos ou não a tratamento superficial da casca armazenados em diferentes ambientes / Quality of quail eggs submitted or no to surface treatment of the shell stored in different environments

With the aim of evaluating the quality of eggs of Japanese quail treated superficially, by immersion in mineral oil or propolis solution, simultaneous experiments were conducted in two environments, without refrigeration (Experiment 1) and with refrigeration (Experiment 2). For each experiment, were selected 360 intact eggs distributed in a completely randomized design in factorial 3 x 5 (untreated eggs; eggs immersed in propolis or eggs immersed in mineral oil, evaluated for five storage times: 7; 14; 21; 28 and 35 days), each treatment consisted of four replicates of six eggs each. The eggs had increased weight loss, decrease in specific gravity and growth the weight and the pH of the yolk, besides the reduced the pH of the albumen and their respective weight with advancing storage time in the absence of cooling (Experiment 1), whether treated or not in the shell. However, the surface treatment with mineral oil promoted protection against progressive loss of weight and decreased specific gravity, making them less intense with advancing the storage period without refrigeration. In the Experiment 2, the immersion of eggs in mineral oil promoted less weight loss, higher specific weight, greater weight of the yolk and the albumen during storage under refrigeration. The quality of quail eggs submitted of treatment superficial on shell by immersion in mineral oil is preserved for up to five weeks under different environments, with and without refrigeration.

Com o objetivo de avaliar a qualidade de ovos de codornas japonesas tratados superficialmente, através de imersão em óleo mineral ou solução de própolis, foram conduzidos experimentos simultâneos em dois ambientes, sem refrigeração (Experimento 1) e com refrigeração (Experimento 2). Para cada experimento, foram selecionados 360 ovos íntegros distribuídos em delineamento inteiramente casualizado em esquema fatorial 3 x 5 (ovos não tratados; ovos imersos em solução de própolis e ovos imersos em óleo mineral, avaliados durante cinco tempos de armazenamento: 7; 14; 21; 28 e 35 dias), cada tratamento foi composto por seis repetições de quatro ovos cada. Os ovos apresentaram aumento da perda de peso, diminuição do peso específico e aumento do peso e do pH da gema, além de redução do pH do albúmen e de seu respectivo peso com o avançar do tempo de estocagem na ausência de refrigeração (Experimento 1), independente se receberam ou não tratamento na casca. Entretanto, o tratamento superficial com óleo mineral promoveu proteção contra essa perda progressiva de peso e diminuição do peso específico, tornando-as menos intensas com o avançar do período de estocagem sem refrigeração. No Experimento 2, a imersão dos ovos em óleo mineral conferiu menor perda de peso, maior peso específico, maior peso de gema e de albúmen durante o armazenamento sob refrigeração.A qualidade de ovos de codornas submetidos a tratamento superficial da casca por imersão em óleo mineral é preservada por até cinco semanas em diferentes ambientes, sem e com refrigeração.

Fractal analysis of extra-embryonic vascularization in Japanese quail embryos exposed to extremely low frequency magnetic fields.

Magnetic fields (MF) can alter the dynamic behavior of vascular tissue and may have a stimulatory or inhibitory effect on blood vessel growth. Fractal geometry has been used in several studies as a tool to describe the development of blood vascular networks. Due to its self-similarity, irregularity, fractional dimension, and dependence on the scale of vessel dimensions, vascular networks can be taken as fractal objects. In this work, we calculated the fractal dimension by the methods of box counting (D(bc)) and information dimension (D(inf)) to evaluate the development of blood vessels of the yolk sac membrane (YSM) from quail embryos exposed to MF with a magnetic flux density of 1 mT and a frequency of 60 Hz. The obtained results showed that when the MF was applied to embryos aged between 48 and 72 h, in sessions of 2 h (6 h/day) and 3 h (9 h/day) with exposure intervals between 6 and 5 h, respectively, blood vascular formation was inhibited. Exposure sessions shorter than 2 h or longer than 3 h had no observable change on the vascular process. In contrast, the magnetic field had no observable change on the YSM vascular network for embryos aged between 72 and 96 h, irrespective of the exposure time. In conclusion, these results show a "window effect" regarding exposure time.

Edad al primer huevo en codorniz japonesa (Coturnix coturnix japonica) bajo condiciones experimentales / Age at the first egg in japanese quail (Coturnix coturnix japonica) under experimental conditions

Con el propósito de estudiar el efecto del mes de nacimiento, granja de origen, peso del huevo, peso corporal, color y brillo de la cáscara del huevo sobre la edad al primer huevo (EPH) en codornices, se evaluaron 115 hembras provenientes de huevos fértiles adquiridos en cuatro granjas del centro del país. El experimento se llevó a cabo en la Facultad de Agronomía de la Universidad Central de Venezuela en galpones de 4mx4m, cerrados con malla metálica, techo de zinc y piso de cemento que albergaban jaulas individuales de 50 cm. × 20 cm. Se registró peso de los huevos, fecha de nacimiento, color y brillo de huevos, peso vivo, consumo de alimento y producción de huevos. Se utilizó un diseño completamente aleatorizado,y se analizó 115 observaciones con un modelo lineal aditivo. Sólo se encontró efecto significativo del mes de nacimiento sobre la edad al primer huevo (P=0,001), siendo abril y diciembre los mejores meses, con diferencias de 40 días respecto al peor mes (junio). El peso del huevo afectó la EPH (P=0,0022; b=–4,46 ± 1,42 días/g), donde por cada gramo extra de peso del huevo se redujo la EPH en 4,46 días, mientras que por cada gramo de peso corporal adicional, las hembras incrementan su EPH en 0,52 días (P=0,0001, b=0,52 ± 0,07 días/g). Se concluye que las hembras provenientes de huevos pesados y que nacen en meses de menor precipitación, resultan más precoces.

With the aim of determine the effect of the month of birth, farm of origin, weight of the egg, body weigth, color and sheen of eggshell on age at first egg (AFE) in quails, there were evaluated 115 females from fertile eggs acquired in four farms of the center of the country. The experiment was carried out in the Agronomy School of the Central University of Venezuela in sheds of 40mx4m, closed with metalic net, zinc roof and cement floor, and they were sheltering individual cages of 50 cm. x 20 cm. The date of birth weight, color and sheen of eggshell, body weight, food comsumption and egg production were registered. A completely randomized design was used, and 115 observations were analyzed by a additive linear model. Only birth month had a significant (P=0.001) effect on AFE , being april and december the months, with differences of 40 days with regard to the worst month (June). The weight of the egg affected the EPH (P=0.0022; b = -4.46 ±1.24 days/g), for every extra gram of weight of the egg the EPH diminished in 4.46 days; whereas for every extra gram of corporal weigtht, EFH increase in 0.52 days (P= 0.0001, b= 0.52 ± 0.07days/g). It can be concluded that the females from heavy eggs and that they are born in months of minor rainfall, had their first egg early in life.

Detection of reticuloendotheliosis virus by immunohistochemistry and in situ hybridization in experimentally infected Japanese quail embryos and archived formalin-fixed and paraffin-embedded tumours.

Reticuloendotheliosis virus (REV) infection can result in immunosuppression, a runting syndrome, high mortality, acute reticulum cell neoplasia, or T-cell and/or B-cell lymphomas, in a variety of domestic and wild birds. Histopathological changes in REV infection are not sufficient to differentiate it from avian lymphoid leukosis and Marek's disease, and currently there are no available in situ diagnostic methods for detection of active REV presence in pathologic specimens. To develop immunohistochemistry and in situ hybridization assays for detection of REV active infections, experimentally inoculated Japanese quail embryos, and archived formalin-fixed paraffin-embedded tissues from natural and experimental reticuloendotheliosis cases in chickens and turkeys, were examined. The in situ hybridization and immunohistochemistry assays proved to be efficient for the detection of several REV strains in Japanese quail embryos during active infection, whereas these assays were much less sensitive when applied to archived tissue samples from chronically infected birds with lymphoid tumours. The diagnostic assays developed in this study have potential as diagnostic tools for detection of active REV infections.

Distribution patterns of neural-crest-derived melanocyte precursor cells in the quail embryo.

BACKGROUND: In vertebrate embryos, migration of trunk neural crest cells (NCC) proceeds mainly in two streams: a dorsoventral path between the neural tube and somites, and a dorsolateral one between somites and ectoderm. This last pathway is taken by melanocyte precursor cells (MPC) homing the skin, while pigment cells seeding internal organs and the peritoneal wall follow the dorsoventral pathway. Early routes taken by subpopulations of NCC have been well documented using the quail-chick chimaera system and monoclonal antibodies to NCC. However, very little is known about the advanced migratory behavior of MPC, which determines their late distribution patterns at different embryonic axial levels. METHODS: Histological sections of neck, thorax, and abdomen of 6.5 to 9 day quail embryos submitted to DOPA reaction (tyrosinase activity) were used. In four concentric areas--dorsal and ventrally subdivided--the relative density of MPC was determined by morphometric methods. RESULTS: The relative regional density of MPC from their individualization as DOPA-positive putative pigment cells until their definitive seeding in the epidermis showed a progressively higher cell density from deeper to peripheral zones in all three levels studied, with peaks of cell density suggesting a centrifugal pattern occurring in at least two waves of migratory cells. CONCLUSIONS: The spatial distribution of the MPC varies according to both the axial level and the developmental stage of the embryo. Furthermore, the general pattern of centrifugal distribution observed might be attributed to a different timing of cell differentiation closely related to their migratory behavior.