Fat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age

This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.(AU)

Fat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age

This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.

Laying performance and egg quality of Japanese quails fed diets containing castor meal and enzyme complex

The objective of this study was to evaluate the effect of diets formulated with corn plus soybean meal (CSM) or with 21% autoclaved castor meal (ACM), with the addition of two enzyme complexes (EC1 and EC2), on the performance and egg quality of laying quail. Two hundred and sixteen quails were selected by egg production and weight uniformity and distributed in a completely randomized design with six treatments (in a 2 × 3 cross-factorial arrangement) and six replicates with six birds each. Three CSM and three ACM diets supplemented with EC1, EC2, or unsupplemented were established. The trial lasted three cycles of 21 days. Feed intake, laying rate, egg mass, feed conversion per egg mass, and feed conversion per dozen eggs did not differ. The use of ACM diet reduced egg (EW), yolk (YW), and eggshell (SW) weights, egg specific gravity and increased yolk color. However, EW and YW were similar among quails fed diets containing CSM and ACM when supplemented with CE1.The use of enzyme complex containing xylanase, b-glucanase, and phytase is recommended when 21% autoclaved castor mealis included in the diet of laying quails.(AU)

Laying performance and egg quality of Japanese quails fed diets containing castor meal and enzyme complex

The objective of this study was to evaluate the effect of diets formulated with corn plus soybean meal (CSM) or with 21% autoclaved castor meal (ACM), with the addition of two enzyme complexes (EC1 and EC2), on the performance and egg quality of laying quail. Two hundred and sixteen quails were selected by egg production and weight uniformity and distributed in a completely randomized design with six treatments (in a 2 × 3 cross-factorial arrangement) and six replicates with six birds each. Three CSM and three ACM diets supplemented with EC1, EC2, or unsupplemented were established. The trial lasted three cycles of 21 days. Feed intake, laying rate, egg mass, feed conversion per egg mass, and feed conversion per dozen eggs did not differ. The use of ACM diet reduced egg (EW), yolk (YW), and eggshell (SW) weights, egg specific gravity and increased yolk color. However, EW and YW were similar among quails fed diets containing CSM and ACM when supplemented with CE1.The use of enzyme complex containing xylanase, b-glucanase, and phytase is recommended when 21% autoclaved castor mealis included in the diet of laying quails.

Gene polymorphisms are associated with eggshell ultrastructure organization in hens

Eggshell ultrastructure organization, including effective layer thickness, mammillary layer thickness, and average size of mammillary cones, is important for breeding and significantly influences eggshell mechanical properties. Several matrix proteins were known to be important in eggshell formation. However, the proteins and variations that determine eggshell ultrastructure organization are not known. Results: In this study, 17 single-nucleotide polymorphisms of three major genes in a hen population using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Five single-nucleotide polymorphisms with a very low minor allele frequency ( 1%) were excluded from further analysis. The remaining 12 single-nucleotide polymorphisms in Hardy-Weinberg equilibrium were used for analysis of associations with eggshell ultrastructure organization. Associations were found for (i) ovocleidin-116 with effective layer thickness (EFF), mammillary layer thickness (MAM), and average size of mammillary cones (SMAM); (ii) ovalbumin with eggshell thickness (ESH), effective layer thickness, and density of the mammillary cone (DMAM); and (iii) calmodulin1 with density of the mammillary cone. Conclusions: The single-nucleotide polymorphisms identified in the present study may be used as potential markers to improve eggshell quality.(AU)

Gene polymorphisms are associated with eggshell ultrastructure organization in hens

Eggshell ultrastructure organization, including effective layer thickness, mammillary layer thickness, and average size of mammillary cones, is important for breeding and significantly influences eggshell mechanical properties. Several matrix proteins were known to be important in eggshell formation. However, the proteins and variations that determine eggshell ultrastructure organization are not known. Results: In this study, 17 single-nucleotide polymorphisms of three major genes in a hen population using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Five single-nucleotide polymorphisms with a very low minor allele frequency ( 1%) were excluded from further analysis. The remaining 12 single-nucleotide polymorphisms in Hardy-Weinberg equilibrium were used for analysis of associations with eggshell ultrastructure organization. Associations were found for (i) ovocleidin-116 with effective layer thickness (EFF), mammillary layer thickness (MAM), and average size of mammillary cones (SMAM); (ii) ovalbumin with eggshell thickness (ESH), effective layer thickness, and density of the mammillary cone (DMAM); and (iii) calmodulin1 with density of the mammillary cone. Conclusions: The single-nucleotide polymorphisms identified in the present study may be used as potential markers to improve eggshell quality.

Effects of Dietary Protein Level and Betaine Supplementation on Nutrient Digestibility and Performance of Japanese Quails

ABSTRACT This study investigated the effects of dietary protein levels and betaine supplementation on nutrient digestibility and performance of Japanese quails. In total, 765 Japanese quails were randomly assigned to a 3×3 factorial arrangement, with five replicates of 17 quails each. Three basal diets were formulated to contain three crude protein levels (16.5, 18.0, and 19.5%). Each protein level was supplemented with 0, 0.06, and 0.12% betaine. The diet with 16.5% dietary crude protein with no betaine supplementation resulted in the lowest crude fiber digestibility, while the 18.0% CP diet supplemented with 0.12% betaine generated the highest crude fiber digestibility (p 0.05). The diets with 18.0 and 19.5% crude protein increased crude fiber digestibility, but reduced ether extract digestibility (p 0.01). Moreover, betaine supplementation increased dry matter, crude protein, crude fiber, and crude ash (p 0.01) digestibility and tended to increase ether extract digestibility (p=0.09). The increase in egg weight for the 18.0 and 19.5% protein diets was correlated with a decrease in feed conversion ratio (p 0.05). However, feed intake and egg production were not affected by protein levels. Betaine supplementation enhanced all performance variables (p 0.01). The diets with 18.0 and 19.5% crude protein resulted in heavier yolks and eggshells than the 16.5% crude protein diet (p 0.05), whereas betaine supplementation increased yolk, albumen, and eggshell weight (p 0.01). The 18.0 and 19.5% protein diets produced similar responses in most evaluated parameters. Laying Japanese quails can be fed diets with 18.0% crude protein. Moreover, betaine supplementation provided several benefits, and particularly improved nutrient digestibility, performance, and egg quality.(AU)

Effects of Dietary Protein Level and Betaine Supplementation on Nutrient Digestibility and Performance of Japanese Quails

ABSTRACT This study investigated the effects of dietary protein levels and betaine supplementation on nutrient digestibility and performance of Japanese quails. In total, 765 Japanese quails were randomly assigned to a 3×3 factorial arrangement, with five replicates of 17 quails each. Three basal diets were formulated to contain three crude protein levels (16.5, 18.0, and 19.5%). Each protein level was supplemented with 0, 0.06, and 0.12% betaine. The diet with 16.5% dietary crude protein with no betaine supplementation resulted in the lowest crude fiber digestibility, while the 18.0% CP diet supplemented with 0.12% betaine generated the highest crude fiber digestibility (p 0.05). The diets with 18.0 and 19.5% crude protein increased crude fiber digestibility, but reduced ether extract digestibility (p 0.01). Moreover, betaine supplementation increased dry matter, crude protein, crude fiber, and crude ash (p 0.01) digestibility and tended to increase ether extract digestibility (p=0.09). The increase in egg weight for the 18.0 and 19.5% protein diets was correlated with a decrease in feed conversion ratio (p 0.05). However, feed intake and egg production were not affected by protein levels. Betaine supplementation enhanced all performance variables (p 0.01). The diets with 18.0 and 19.5% crude protein resulted in heavier yolks and eggshells than the 16.5% crude protein diet (p 0.05), whereas betaine supplementation increased yolk, albumen, and eggshell weight (p 0.01). The 18.0 and 19.5% protein diets produced similar responses in most evaluated parameters. Laying Japanese quails can be fed diets with 18.0% crude protein. Moreover, betaine supplementation provided several benefits, and particularly improved nutrient digestibility, performance, and egg quality.

AVALIAÇÃO DA QUALIDADE, FERTILIDADE E PROTEÔMICA DE OVOS DE CASCA VÍTREA DE REPRODUTORAS PESADAS

Objetivou-se avaliar a influência do tipo de casca (normal e vítrea) sobre os parâmetros de fertilidade, qualidade interna e externa de ovos, além da proteômica das estruturas da casca de reprodutoras pesadas. Para avaliação dos parâmetros de qualidade dos ovos, o experimento foi dividido em duas fases. No experimento 1 foram avaliados 240 ovos (120 de casca normal e 120 de casca vítrea), no prazo máximo de 24 horas após a postura, coletados igualmente entre quatro lotes de avós de frangos de corte da linhagem Ross, de duas linhas (macho e fêmea) e duas idades (38 e 46 semanas). No experimento 2 foram utilizadas 5 bandejas de 162 ovos de casca normal e a mesma quantidade para casca vítrea, de um lote de avós da linha macho da genética Cobb, com 40 semanas de idade. Para a análise proteômica foram utilizados ovos de quatro lotes de avós de frangos de corte (mesmos lotes do experimento 1 de qualidade), sendo selecionados 80 ovos, 20 de cada lote (pool de 10 ovos de casca normal e 10 ovos de casca vítrea) pela característica externa da casca. De cada lote foram coletados fragmentos da estrutura da casca (cascas e membranas das cascas), triturados manualmente, homogeneizados e depois selecionado 1 grama de cada pool para formar a análise final. Ovos de casca normal apresentaram maiores médias que ovos de casca vítrea para as variáveis Porcentagem de Albúmen, Índice de Gema, Índice de Albúmen e unidades Haugh, e menor média para Porcentagem de Magnésio na casca. A perda de umidade na incubação foi maior para os ovos de casca vítrea, em comparação com ovos de casca normal. Por proteômica, foram identificadas 309 proteínas (2989 peptídeos) diferentes nas 8 amostras avaliadas das estruturas da casca. Após análise estatística comparando todos os lotes e proteínas, foi identificada diferença somente para duas proteínas (ATPase- A0A1Y4CB63 e OVA fragmentos idêntica à OvoalbuminaA0A2H4Y8Q2), sendo que as diferenças entre as proporções foram significativamente maiores para casca vítrea. Dentre as proteínas encontradas destacam-se: Ovotransferrina, Ovalbumina, proteína OVA fragmentos, Proteína Y relacinado à Ovoalbumina, Serotransferrina, Ovomucóide, 2-c-methyl glycerol 4-phosphate cytidylytransferase, SERPIN, Proteína Não Caracterizada (Gene Ovostatina), Aplha-1-acid glycoprotein, ATPase e Proteína Não Caracterizada (Gene B5G11_16010). Ovos de casca vítrea têm qualidade interna inferior em relação aos de casca normal, além de perderem mais umidade na incubação (provavelmente por alterações na matéria orgânica/proteica na casca). A partir dos achados proteômicos é possível especular alguma alteração de expressão gênica no útero, que pode levar a superexpressões proteicas (por exemplo proteína OVA/ Ovoalbumina), com aumento do conteúdo orgânico da matriz e desarranjos nas camadas biomineralizadas de ovos de casca vítrea. Portanto, sugere-se novas pesquisas de perfil molecular entre as diferentes estruturas dos dois tipos de casca, além de estudos de manejos diferenciados a nível de campo e incubatório para ovos de casca vítrea.

The objective was to evaluate the influence of the eggshell type (normal and vitreous) on the parameters of fertility, internal and external quality of eggs, in addition to the proteomics of eggshell structures of broiler breeders. To evaluate the egg quality parameters, the experiment was divided into two phases. In experiment 1, 240 eggs (120 of normal shell and 120 of vitreous shell) were evaluated, within a maximum of 24 hours after laying, collected equally between four lots of Ross broilers, two lines (male and female) and two ages (38 and 46 weeks). In experiment 2, five trays of 162 eggs with normal eggshell and the same amount for vitreous eggshell were used, from a lot of grandparents of the male line of the Cobb genetics, at 40 weeks of age. For the proteomic analysis, eggs from four lots of broiler grandparents (same lots from experiment 1 of quality) were used, with 80 eggs selected, 20 from each lot (pool of 10 eggs with normal shell and 10 eggs with vitreous shell) by the external characteristic of the shell. Fragments of the shell structure (shells and shells membranes) were collected from each lot, manually crushed, homogenized and then selected 1 g from each pool to form the final analysis. Normal shell eggs showed higher averages than vitreous shell eggs for the variables Albumin Percent, Yolk Index, Albumin Index and Haugh units, and lower average for Magnesium Percent in the shell. The loss of humidity in the incubation was higher for eggs with vitreous shell, compared with eggs with normal shell. By proteomics, 309 different proteins (2989 peptides) were identified in the 8 samples evaluated from the shell structures. After statistical analysis comparing all lots and proteins, a difference was identified only for two proteins (ATPase- A0A1Y4CB63 and OVA fragments identical to OvoalbuminA0A2H4Y8Q2), and the differences between the proportions were significantly higher for vitreous shell. Among the proteins found, we highlight: Ovotransferrin, Ovalbumin, OVA protein fragments, Protein Y related to Ovoalbumin, Serotransferrin, Ovomucoid, 2-c-methyl glycerol 4-phosphate cytidylytransferase, SERPIN, Uncharacterized Protein (Ovostatin Gene), Aplha-1 -acid glycoprotein, ATPase and Uncharacterized Protein (Gene B5G11_16010). Vitreous shell eggs have a lower internal quality than normal shell eggs, in addition to losing more humidity during incubation (probably due to changes in the organic / protein matter in the shell). From the proteomic findings it is possible to speculate some alteration of gene expression in the uterus, which can lead to protein overexpression (for example OVA / Ovoalbumin protein), with an increase in the organic content of the matrix, and breakdowns in the biomineralized layers of vitreous shell eggs. Therefore, we suggest new researches of molecular profile between the different structures of the two types of shell, in addition to studies of different field and hatchery managements for vitreous shell eggs.

QUALIDADE BACTERIOLÓGICA E FUNCIONAL DE OVOS PROVENIENTES DE CRIAÇÃO CAIPIRA SUBMETIDOS À HIGIENIZAÇÃO POR MÉTODO ÚMIDO E RADIAÇÃO UV-C

O ovo é um alimento completo que contém proteínas de alto valor biológico a preços reduzidos o que viabiliza seu consumo por todas as parcelas da população. Além do consumo in natura, os ovos também são utilizados na formulação de produtos alimentícios devido às propriedades funcionais das proteínas que possuem.Entretanto, o consumo de ovos está comumente associado com surtos envolvendo agentes etiológicos veiculados por alimentos. Um dos microrganismos mais identificados em surtos alimentares é Escherichia coli e por estar naturalmente presente no trato intestinal das aves, a bactéria é frequentemente isolada da superfície dos ovos. Após a postura, as cascas podem ser contaminadas por microrganismos presentes no ambiente. Com objetivo de reduzir a população bacteriológica inicial da casca dos ovos e oferecer um produto sanitariamente adequado para o consumidor, alguns métodos de higienização são realizados. Apesar disso, poucas metodologias são acessíveis aos pequenos produtores que usualmente lavam os ovos ou higienizam com panos úmidos ou secos. No presente estudo avaliou-se o efeito da radiação ultravioleta (UV-C) na redução da enumeração de Escherichia coli, coliformes totaise da contagem de bactérias heterotróficas aeróbias mesófilas na superfície de ovos caipiras. Além disso, buscou-se compreender o impacto da radiação na capacidade de gelificação e na formação de espuma dos ovos e comparou-se o tratamento com o método de higienização úmida utilizado por pequenos produtores rurais. Foi utilizada a dose de 26,88J/cm² para a descontaminação da superfície de ovos caipira. Detectou-se redução de 2 a 3 logs10UFC/g para bactérias heterotróficas aeróbias mesófilas, 3 logs10 UFC/g de coliformes totais e de 2 a 3 logs10UFC/g de Escherichia coli nos ovos irradiados. A dose utilizada também foi capaz de aumentar o volume e a estabilidade da espuma. Não foram observadas diferenças significativas na textura de géis. Contudo, a reprodução do método retratado pelos pequenos produtores (higienização úmida) foi capaz de aumentar a contagem bactérias heterotróficas aeróbias mesófilas e diminuir o volume e a estabilidade da espuma. Com base nos resultados encontrados sugere-se que metodologia UV-C aplicada deve ser considerada uma alternativa economicamente viável para descontaminação bacteriológica da casca de ovos em pequenas propriedades rurais.

The egg is a complete food that contains proteins of high biological value at reduced prices which enables its consumption by all portions of the population. In addition to fresh consumption, eggs are also used in the formulation of food products due to the functional properties of the proteins they have. However, egg consumption is commonly associated with outbreaks involving foodborne etiological agents. One of the most identified microorganisms in food outbreaks is Escherichia coli and because it is naturally present in the intestinal tract of birds, the bacterium is often isolated from the surface of eggs. After laying, the barks may be contaminated by microorganisms present in the environment. In order to reduce the initial bacteriological population of the eggshell and offer a sanitary product suitable for the consumer, some cleaning methods are performed. Nevertheless, few methodologies are accessible to small producers who usually wash eggs or sanitize with wet or dry cloths. The present study evaluated the effect of ultraviolet radiation (UV-C) on the reduction of Escherichia coli enumeration, total coliforms and the count of mesophilic aerobic heterotrophic bacteria on the surface of free-range eggs. In addition, we sought to understand the impact of radiation on the gelability and foaming of eggs and compared the treatment with the method of wet cleaning used by small farmers. A dose of 26.88J / cm² was used for decontamination of the surface of rustic eggs. A reduction of 2 to 3 logs10 CFU / g was detected for mesophilic aerobic heterotrophic bacteria, 3 logs10 CFU / g total coliforms and 2 to 3 logs10 CFU / g Escherichia coli in irradiated eggs. The dose used was also able to increase the volume and stability of the foam. No significant differences in gel texture were observed. However, reproduction of the method portrayed by small producers (wet cleaning) was able to increase the mesophilic aerobic heterotrophic bacteria count and decrease the foam volume and stability. Based on the results it is suggested that the applied UV-C methodology should be considered an economically viable alternative for bacteriological decontamination of eggshell in small rural properties.

SOJA EXTRUSADA NA ALIMENTAÇÃO DE CODORNAS JAPONESAS

Objetivou-se avaliar o efeito de níveis crescentes de soja extrusada (0; 7,5; 15; 22,5 e 30%) em substituição ao farelo de soja na dieta de codornas japonesas em fase de postura, sobre desempenho, digestibilidade, qualidade de ovos, biometria do trato gastrointestinal, biometria dos ossos tíbia e fêmur, perfil bioquímico do soro, assim como das vísceras fígado e pâncreas, e também a atividade específica das enzimas hepáticas e pancreáticas. Foram utilizadas 180 codornas fêmeas da espécie Coturnix coturnix japônica com idade de aproximadamente 150 dias de vida, uniformizadas pelo peso corporal, distribuídas em gaiolas de arame galvanizado com 38 cm de comprimento × 40 cm de largura × 23 cm de altura. O delineamento foi inteiramente ao acaso (DIC), sendo cinco tratamentos e seis repetições contendo seis aves por repetição. O experimento teve a duração de 84 dias, sendo realizados três ciclos de produção, com 28 dias cada ciclo. Os resultados foram submetidos à análise de variância e quando o teste F foi significativo, foi aplicada a análise de regressão polinomial, a 5% de probabilidade. A utilização de até 30% de SE melhora a conversão alimentar por dúzia de ovos e não afeta as demais características de desempenho, melhora o coeficiente metabolização de extrato etéreo. A qualidade de ovos é diretamente afetada pela inclusão de SE, que reduz a unidade Haugh, índice de gema e albúmen e altura do albúmen, influenciadas de forma negativa. A qualidade da casca dos ovos, biometria dos órgãos digestivos, biometria dos ossos (tíbia e fêmur), não foram influenciados pela utilização do nível de até 30% de SE. Houve aumento dos teores séricos de ureia, mostrando o bom funcionamento e saúde do fígado. As proteínas totais e lipase do pâncreas, assim como a atividade específica deste órgão, não foram influenciados pela utilização do nível de até 30% de SE. Conclui-se que a substituição de farelo de soja por soja extrusada ao nível de 30% na alimentação de codornas japonesas, reduz significativamente a conversão alimentar por dúzia de ovos produzidos e aumenta o coeficiente de metabolização de extrato etéreo, reduzindo a unidade Haugh dos ovos; contudo, tal redução da qualidade ainda enquadra-se nos valores de excelência de tal avaliação.

The aim of this study was to evaluate the effect of extruded soybean (0, 7.5, 15, 22.5 and 30%) increasing levels in soybean meal replacement on the diet of Japanese laying quails on performance, digestibility, eggs quality, gastrointestinal tract biometry, tibia and femur bones biometry, serum biochemical profile, as well as the liver and pancreas viscera and also the specific activity of the liver and pancreatic enzymes. A total of 180 female quails of the species Coturnix coturnix japonica species with approximately 150 days of life standardized by body weight, distributed in galvanized wire measuring 38 cm long × 40 cm wide × 23 cm height were used. The design was completely randomized (CAD), with five treatments and six replicates containing six birds per replicate. The experiment lasted for 84 days, with three production cycles, with 28 days each one. The results were submitted to analysis of variance and when the F test was significant, the polynomial regression analysis was applied, at 5% probability. The use of up to 30% ES improves the feed conversion per dozen eggs and does not affect others performance characteristics, improving the ethereal extract metabolism coefficient. The egg quality is directly affected by the ES inclusion which reduces the Haugh unit, yolk and albumen index, albumin height which were negatively influenced. Eggshell quality, digestive organs biometry, bone biometrics (tibia and femur) were not influenced by the use of up to 30% ES. There was an increase in serum urea levels, showing the good functioning and health of the liver. The total proteins and lipase of the pancreas as well as the specific activity of this organ were not influenced by the use of up to 30% ES level. It is concluded that the substitution of soybean meal by extruded soybean at the 30% level in Japanese quails feed significantly reduces feed conversion per dozen eggs produced and increases the ethereal extract metabolism coefficient, reducing the Haugh unit of the eggs. However, such a reduction in quality still fits the excellence values of such evaluation.

Effect of different levels of methionine, protein and tallow on the productive performance and egg quality of laying hens in the late-phase production

An experiment was conducted to determine the effects of different levels of methionine, protein and tallow on productive performance and egg quality of laying hens in the late phase of production. A completely randomized design with a 3×2×2 factorial arrangement, with three levels (0.34, 0.31, and 0.27%) of methionine (MET), two levels (12.8 and 14.7%) of protein (PRO) and two levels (1 and 3%) of tallow (TAL) with constant level of linoleic acid (1.55 ± 0.02%), was used. A number of 144 Hi-Line W-36 layers from 70 to 76 wk of age was randomly distributed into 12 treatment groups with 4 replicates of 3 hens each. Egg production and egg weight were daily recorded and feed intake and egg quality traits were recorded every 2 wk. There was a significant interaction between PRO levels and TAL for egg weight. Low levels of TAL and PRO decreased egg weight throughout the experiment. High levels of MET and TAL with concomitant reduced PRO, increased eggshell thickness, and a significant interaction between levels of MET, PRO and TAL was observed during the experiment (70 to 76 wk). Low level of protein (12.8%) significantly decreased albumen weight in the third 2-wk period. Yolk color increased when hens were fed low levels of PRO and TAL. Results of this experiment indicated that the simultaneous reduction of dietary PRO and MET in diets of Hi-Line W-36 laying hens in the late phase of production, reduced egg weight (P<0.05). Productive performance and egg quality were not affected by 12 and 20% reduction of PRO and MET, respectively. It seems that decreasing the levels of MET and PRO to lower than the recommended values can decrease egg weight without negative effects on productive performance and egg quality of laying hens in the late phase of production.(AU)

QUALIDADE DE OVOS DE CODORNAS COMERCIALIZADOS IN NATURA NA CIDADE DE PELOTAS E O EFEITO DA PIGMENTAÇÃO DA CASCA SOBRE O TEMPO DE ARMAZENAMENTO

O ovo de codorna é um alimento rico em nutrientes, fonte de vitaminas e proteínas e sua venda ocorre através de rede de supermercados normalmente sem o uso da refrigeração. Por outro lado, a casca do ovo tem a função de proteger a clara e a gema e dependendo da genética da ave pode apresentar maior ou menor porcentagem de manchas escuras. Existem evidências não comprovadas de que a pigmentação da casca do ovo tem influência sobre a sua qualidade durante o armazenamento. Para descrever a qualidade dos ovos vendidos na cidade de Pelotas e para comprovar a hipótese de que a pigmentação da casca tem influência sobre o tempo de prateleira foi realizado este estudo em duas etapas: 1ª) Amostragem de ovos de codornas vendidos em supermercados da cidade de Pelotas/RS. 2ª) Avaliação da influência da pigmentação da casca do ovo no tempo de conservação dos ovos através dos seguintes fatores de estudo: 1) controle negativo sem extração da pigmentação da casca do ovo, 2) controle positivo - rápida imersão dos ovos em solução de ácido acético sem retirar a pigmentação da casca e 3) extração da pigmentação da casca de ovos imersos em solução de ácido acético. Todos os fatores foram avaliados com 0, 10, 15, 21 e 25 dias de conservação. Para verificar a associação da pigmentação com a qualidade do ovo armazenada também foram comparados três métodos de classificação de pigmentação de casca dos ovos: método do escore, Determinador Digital de Áreas (DDA) de pigmentos e método da pesagem do pigmento em papel filtro. Na primeira etapa as variáveis de qualidade foram avaliadas por estatística descritiva e por ANOVA unifatorial. Na segunda etapa foi utilizada análise de regressão linear para determinar o efeito da pigmentação da casca e do tempo de armazenamento bem como a interação ente estes fatores. Também foi utilizada o método de Pearson para verificar a correlação entre os métodos de determinação da pigmentação. No período avaliado, os resultados do estudo demonstraram que existe uma oferta de ovos de codorna com qualidade apenas regular nos supermercados da cidade de Pelotas. Foi demonstrado que a qualidade do ovo foi reduzida pelo tempo de armazenamento sem que haja nenhuma associação significativa com o nível de pigmentação da casca.

The quails egg is rich in nutrients, a source of vitamins and proteins and its trade-in usually happens through the supermarket networks without the use of refrigeration. On the other hand, the eggshell protects the albumen and the yolk and, according to the genetics of birds, it may affect the percentage of dark spots in the shell. There are evidences not yet proven about the influence of the pigmentation of the shell of the eggs on their quality during the storage period. In order to describe the quality of eggs sold in the municipality of Pelotas and to prove the hypothesis that the pigmentation of the shell has influences on their shelf time this study was conducted in two stages: 1 st ) the sampling of quails eggs that were being sold in supermarkets of Pelotas, RS, Brazil; 2 nd ) the influence of eggshells pigmentation in the eggs conservation time by the three following factors: 1) negative control, without extraction of the eggshells pigmentation, 2) positive control, with a rapid immersion of the eggs in acetic acid solution not removing shell pigmentation, and 3) extraction of the shells pigmentation of eggs immersed in acetic acid solution. All factors were evaluated at 0, 10, 15, 21 and 25 days of storage. In order to assess the association of the pigmentation with the quality of the stored eggs three eggshells pigmentation classification methods were also compared: scoring method, Digital Area Determiner of pigments and the weighing of pigments in filter paper method. In the first stage, the quality variables were analyzed by descriptive statistics and by unifactorial ANOVA. In the second stage, the linear regression analysis was used to dete rmine the effect of the eggs pigmentation and of the storage time as well as the interaction between these factors. Pearson's method was also used to check the correlation between the three methods that were used to quantify the pigmentation. In the evaluated period, the results of the study showed that there is a supply of quails eggs in the supermarkets of Pelotas qualified only as regular. It was shown that the quality of the eggs due to storage time was reduced, but with no significant association with the degree of the shell pigmentation.

Research on eggshell structure and quality: an historical overview

The eggshell is an important structure for two reasons. Firstly it forms an embryonic chamber for the developing chick, providing mechanical protection and a controlled gas exchange medium. Secondly it is a container for the market egg, providing protection of the contents and a unique package for a valuable food. The superficial structure of the shell has been known for over 100 years. The shell consists of 97% calcium carbonate, and this is provided to the hen in the diet. However, the chemical must be broken down in the digestive system and then re-synthesized in the shell gland to form the shell. This results in a turnover of blood Ca of ~ 100 times each 24 hours. Provision of calcium to layers has been researched at length, but the key work, conducted at Cornell University in the 1960's, showed the necessity for sources with large particle size, for example, oyster shells. Subsequent research has defined guidelines that, if correctly followed, will yield reliable and optimum eggshell quality. Breakage or cracking of eggshells in market channels is a serious concern. Cracks result from a combination of shell strength and integrity, and the extent of the "insult" received by the egg during handling. Measurement of shell strength, and assessment of "insults" is important to the poultry industry. Most recent research has identified the ultra-structure of the shell, with resulting opportunities for industrial remedies, and possible new selection criteria, to ensure maximum shell quality throughout the egg industry.

Research on eggshell structure and quality: an historical overview

The eggshell is an important structure for two reasons. Firstly it forms an embryonic chamber for the developing chick, providing mechanical protection and a controlled gas exchange medium. Secondly it is a container for the market egg, providing protection of the contents and a unique package for a valuable food. The superficial structure of the shell has been known for over 100 years. The shell consists of 97% calcium carbonate, and this is provided to the hen in the diet. However, the chemical must be broken down in the digestive system and then re-synthesized in the shell gland to form the shell. This results in a turnover of blood Ca of ~ 100 times each 24 hours. Provision of calcium to layers has been researched at length, but the key work, conducted at Cornell University in the 1960's, showed the necessity for sources with large particle size, for example, oyster shells. Subsequent research has defined guidelines that, if correctly followed, will yield reliable and optimum eggshell quality. Breakage or cracking of eggshells in market channels is a serious concern. Cracks result from a combination of shell strength and integrity, and the extent of the "insult" received by the egg during handling. Measurement of shell strength, and assessment of "insults" is important to the poultry industry. Most recent research has identified the ultra-structure of the shell, with resulting opportunities for industrial remedies, and possible new selection criteria, to ensure maximum shell quality throughout the egg industry.