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The objective of the current study was to conduct an initial comparison of commercial yeast products in layer hen diets on egg production parameters and the corresponding impact on the cecal microbiota. A short-term feeding study was conducted with 35 laying hens receiving either a control, or 1 of 4 different yeast fermentation products, Immunowall, Hilyses (both from ICC, São Paulo, Brazil), Citristim (ADM, Decatur, IL), and Maxi-Gen Plus (CBS Bio Platforms, Calgary, Canada) with 7 hens per treatment from 40 to 46 wk of age. At the end of the trial, hens were euthanized, the ceca removed and prepared for denatured gradient gel electrophoresis (DGGE) microbial compositional analyses. Although initial shell weight and shell thickness were similar among the treatment groups, hens fed Hilyses had lower shell weight and thickness at the end of the experiment. The most predominant DGGE bands with the strongest intensity were identified as Lactobacillus species and excised double bands were identified as Bacillus, Clostridium, or Lachnospiraceae. In this short-term feeding trial, the commercial yeast products tested had little effect on egg production and shell quality, and only moderately impacted the composition of mature layer hen cecal microbiota.

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External egg quality is an essential parameter of egg production as it relates directly to economic losses. This study evaluated the spatial variability of external egg quality in five naturally ventilated caged vertical aviaries. Differences caused by bird age and thermal and luminous variability within aviaries during winter and summer were analyzed. Data on aviary air temperature, relative humidity, light intensity, and external egg quality were collected at evenly distributed points along the aviary length within three levels of cages. The experimental design was completely randomized in a factorial scheme. In the summer, the highest air temperature and lowest relative humidity were found in central cages, mainly in upper center cages; hens produced eggs with a lower weight and shape index in this area. Similar results were obtained in the winter. In the summer, eggs with lower shell weight and thickness were also produced by hens housed in the central cages, but in the winter, the opposite result was obtained. This study of the spatial variability of external egg quality proved efficient in detecting areas within an aviary with poor quality eggs; improvements to design and management in these areas could help management improve production efficiency and contribute to a sustainable egg supply.

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Three hundred hatching eggs from two layer breeder flocks (Hy-Line Brown and hy-Line W-36; 150 each) were obtained at three different periods of laying cycle (early, middle and late stages). The hatching eggs were randomly taken to assess the impact of chicken strain, age, and hatching time on some eggshell measurements and structures. Results indicate that egg weight, shell percentage and shell thickness were significantly affected by strain, breeder age, and incubation time. Increasing rate of calcium absorption and utilization by the embryos during the embryonic stage clearly reflects the decrease occurred in eggshell strength. The differences of eggshell breaking strength during incubation time periods were 0.41 and 0.55 kg/cm2, the differences due to the incubation time may be due to the higher demand for calcium utilization in the late incubation period (18 days), observed on the10th day of incubation. Brown eggs recorded significant higher calcium percentage in eggshell compared to the white ones. The brown breeder hens recorded significant higher total pores per egg compared to the white egg. Concerning eggshell ultrastructure, total thickness of the brown eggshell was significantly higher than those of the white eggshell by about 3.7%. All parameters, except for total thickness, were significantly affected by the interaction between strain and breeder age. Finally, we conclude that some traits including egg weight, shell percentage, shell thickness, calcium percentages in eggshell, and total pores per egg were significantly affected by strain, breeder age, and incubation time. Eggshell ultrastructure of brown egg was better compared to the white ones.(AU)

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Doxiciclinaé um fármaco do grupo das tetraciclinas indicado para tratamento de diferentes doenças, em principal a coriza infecciosa. Entretanto, antimicrobianos do grupo das tetraciclinas tem capacidade de se ligarem e indisponibilizar minerais importantes para a formação dos ovos. O objetivo do projeto foi de avaliar a interferência da doxiciclina na qualidade de ovos comerciais. Realizou-se um estudo com 100 poedeiras Dekalb Brown®onde se avaliou a cor da gema, unidade Haugh, cor da casca, peso e espessura da casca. O delineamento adotado foi o inteiramente casualizadosem um esquema fatorial 2x2, resultando nos tratamentos: sem doxiciclina ao 5° dia; com doxiciclina ao 5° dia; sem doxiciclina ao 10° dia; com doxiciclina ao 10° dia. Coletou-se 4 ovos por repetição,totalizando 48 ovos analisado por tratamento em cada um dos períodos analisados. Não foram encontradas diferenças significativas entre os tratamentos para as variáveis de qualidade interna dos ovos (cor da gema e unidade Haugh). Para as variáveis de qualidade de casca, houve uma redução significativa dos níveis de amarelo com o uso de doxiciclina por 10 dias, além da redução do peso da casca e da espessura apical e equatorial da casca, principalmente no 10º dia e com o uso de doxiciclina. Conclui-se que o uso da doxiciclina não interfere na qualidade interna dos ovos, porém confere tonalidade acinzentada as cascas, e redução de peso e espessura das mesmas.(AU)

Doxycycline is a drug from the tetracycline group indicated for the treatment of different diseases, mainly infectious coryza. However, antimicrobials from the tetracycline group can bind and make minerals important for egg formation unavailable. The aim of this project is evaluated interference of doxycycline in quality of commercial egg. A study had carried out with 100 Dekalb Brown®laying hens where evaluated the yolk color, Haugh unit,color eggshell, weight and thickness eggshell. The delimitation had completely randomized in a 2x2 factorial scheme, resulting in treatments: without doxycycline at day 5; with doxycycline a day 5; without doxycycline at day 10; with doxycycline at day 10. Four eggs had gathered per replicate, totaling 48 eggs analyzed per treatment in each of the analyzed periods. No significant differences were found between treatments for internal egg quality variables (yolk color and Haugh unit). For the shell quality variables, there was a significant reduction in yellow levels with the use of doxycycline for 10 days, in addition to a reduction in shell weight and apical and equatorial shell thickness, mainly on the 10th day and with the use of doxycycline. It is concluded that the use of the doxycycline does not interfere in the internal quality of the eggs, but it gives a greyish tonality to the eggshells, and reduces their weight and thickness.(AU)

La doxiciclina es un fármaco del grupo de las tetraciclinas indicado para el tratamiento de diferentes enfermedades, principalmente el coriza infeccioso. Sin embargo, los antimicrobianos del grupo de las tetraciclinas tienen la capacidad de unirse y hacer que minerales importantes para la formación de huevos no estén disponibles. El objetivo de este proyecto es evaluar la interferencia de la doxiciclina en la calidad del huevo comercial. Se realizó un estudio con 100 gallinas ponedoras Dekalb Brown®donde se evaluó el color de la yema, unidad Haugh, color del cascarón, peso y grosor del cascarón. La delimitación tuvo completamente al azar en un esquema factorial 2x2,resultando tratamientos: sin doxiciclina en el día 5; con doxiciclina al día 5; sin doxiciclina el día 10; con doxiciclina el día 10. Se habían recolectado cuatro huevos por réplica, totalizando 48 huevos analizados por tratamiento en cada uno de los períodos analizados. No se encontraron diferencias significativas entre tratamientos para las variables de calidad interna del huevo (color de la yema y unidad Haugh). Para las variables de calidad de la cáscara, hubo una reducción significativa de los nivelesde amarillo con el uso de doxiciclina durante 10 días, además de una reducción del peso de la cáscara y del espesor apical y ecuatorial de la cáscara, principalmente al décimo día y con el uso de doxiciclina. Se concluye que el uso de la doxiciclina no interfiere en la calidad interna de los huevos, pero da una tonalidad grisácea a las cáscaras, y reduce su peso y grosor.(AU)

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The objective of this study was to evaluate the effects of Bacillus subtillis PB6, chromium propionate or a combination of the two on the performance, egg and eggshell quality, nutrient metabolizability and serum biochemistry of layer breeders. White Plymouth Rock and Red Rhodes Island breeder hens at 55 weeks of age were allocated in individual cages using a completely randomized block design with 16 replicates. Hens were fed control, control + probiotic (500 g/ton of Bacillus subtilis PB6), control + CrProp (50 g/ton of chromium propionate) and control + probiotic + CrProp diets from 55 to 70 weeks of age. Productive parameters and eggshell quality as well as cortisol and blood biochemistry were grouped each 28 d as well as for the overall period. The metabolizability of nutrients and energy was determined at 70 weeks of age. In the overall period, hens fed the control + probiotic or control + probiotic + CrProp diets had significantly higher egg production, egg mass, shell percentage, thickness and shell strength. The metabolizability of dry matter, nitrogen and energy increased in hens that were fed the control + probiotic + CrProp diet. In conclusion, diets supplemented with Bacillus subtillis PB6 and chromium propionate resulted in improved productive performance, eggshell quality and nutrient metabolizability of layer breeders, without modifying serum cortisol, albumin and triglycerides.

RESUMO

The aim of this study was to evaluate the effects of organic micromineral zinc (Zn) and manganese (Mn) and 25-hydroxycholecalciferol supplementation in late-phase laying hens' diets on performance, egg quality, lipid stability of fresh and stored eggs, and bone quality. The treatments were a basal diet and diets supplemented with 32 mg Zn-Met/kg diet; 26 mg Mn-Met/kg diet; 32 mg Zn-Met/kg diet and 26 mg Mn-Met/kg diet; 1500 IU 25-hydroxycholecalciferol/kg diet; 32 mg Zn-Met/kg diet; 26 mg Mn-Met/kg diet; and 1500 IU 25-hydroxycholecalciferol/kg diet. On performance, the birds supplemented with organic manganese had the lowest feed intake. Regarding egg quality, the birds supplemented with Zn-Met and Mn-Met, with 25-hydroxycholecalciferol alone, and with Zn-Met, Mn-Met and 25-hydroxycholecalciferol presented a greater eggshell thickness than those receiving the basal diet. Lipid stability of the yolk varied only according to storage time. No effect of supplementation was observed on bone quality. Supplementation with Zn-Met and Mn-Met, or associated with 25-hydroxycholecalciferol, or 25-hydroxycholecalciferol alone, improved eggshell thickness in aged white layers. However, the associated or isolated supplementation with these nutrients did not influence performance, lipid stability of fresh and stored egg yolk or bone quality.

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The objective of this study was to evaluate the effects of the dietary supplementation of canthaxanthin and cholecalciferol (25OHD3) to broiler breeders and their progenies on their performance. Eighty 25-wk-old Cobb 500 broiler breeders were distributed according to a completely randomized design in 2 experimental treatments, with 10 replicates of 4 birds each. The treatments consisted of the supplementation or not of a corn-soybean meal diet with canthaxanthin + 25OHD3 to broiler breeders fed from 25 to 62 wk of age. Egg production, fertility, hatchability, hatchability of fertile eggs, embryonic mortality, and egg specific gravity were evaluated. Breeders were inseminated at 35, 45, and 62 wk of age, the eggs were incubated, and the performance of the progenies was evaluated. From the progeny of each breeder age, 300 male chicks were distributed according to a completely randomized design in a 2 × 2 factorial arrangement (chicks from breeders supplemented or not with canthaxanthin + 25OHD3 and chicks supplemented or not with canthaxanthin + 25OHD3), totaling 4 treatments with 5 replicates of 15 birds each. Canthaxanthin + 25OHD3 were supplied to the chicks until 21 D of age. The combination of canthaxanthin and 25OHD3, containing 69 mg of 25OHD3 and 6 g of canthaxanthin, was supplemented at 1 kg/t of feed. Breeders supplemented with canthaxanthin + 25OHD3 showed higher egg production, total hatchability, hatchability of fertile eggs, and lower early embryo mortality compared with those fed the control diet. Broilers from breeders fed canthaxanthin + 25OHD3 and supplemented with this additive up to 21 D of age presented a better feed conversion ratio and higher carcass and breast yields than those derived from nonsupplemented breeders.

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The objective of this study was to evaluate the effect of different trace mineral supplementation sources in the diet of broiler breeders on their performance and on their progenies. In total, 128 Cobb 500 broiler breeders were distributed according to a completely randomized experimental design in 2 experimental treatments. The control group was fed a diet supplemented with inorganic trace minerals (ITM), while the other group was fed a diet supplemented with reduced levels of trace minerals in the organic form. Eggs were collected when breeders were 35, 47, and 53 wk old. Their progeny (450 hatchlings) were divided according to trace mineral supplementation source from the maternal diet, creating 2 treatments with 16 replicates of 15 birds each. Organic trace mineral (OTM) supplementation improved broiler breeder performance, as shown by higher egg production and better eggshell quality of OTM-fed hens compared with those fed ITM. Egg fertility and hatchability were not influenced by the treatments. As to progeny performance, higher weight gain, and consequently, better feed conversion ratio, were obtained in the 41-day-old progenies of OTM-fed breeders, independently of hen age. Maternal diet trace mineral source did not affect broiler carcass, breast meat, or leg yields. The results of the present study show that supplementing broiler breeder diets with organic trace mineral sources enhances the performance of breeders and their progenies.

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Different sanitization methods were evaluated as alternatives to formaldehyde fumigation for the reduction of eggshell and yolk sac microbiological counts, improvement of eggshell quality, incubation parameters, and day-old chick quality. A total of 10,080 hatching eggs were collected from a 70-wk-old commercial broiler breeder flock and distributed in a completely randomized block design with seven treatments: fumigation with paraformaldehyde (5.03 g/m3/30 min), fumigation with ozone (5-15 ppm/30 min), ultraviolet light-C irradiation (8.09 mW/cm2; 120 s; UV-C), hydrogen peroxide spraying (3%; 0.69 mL/egg), peracetic acid spraying (0.3%; 0.69 mL/egg; PAA), water spraying (0.69 mL/egg; water control), and without disinfection (dry control-DC). Spraying eggs with PAA and UV-C significantly reduced aerobic bacteria plate counts compared to the DC group. In addition, eggs disinfected with PAA had lower Enterobacteriaceae counts than the DC and water control groups. Eggshell quality, incubation parameters, and microbiological counts for yolk sac did not differ (P > 0.05) among treatments. This study demonstrated the potential for the application of PAA and UV-C for eggshell disinfection instead of formaldehyde; however, an electronic microscopic evaluation of the eggshell is necessary to determine if these methods cause any damage to the cuticle.

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The study was conducted to determine the interaction of types of maize (Provitamin A-biofortified maize (PABM) versus white maize) and strain of laying birds (Amberlink and Hyline) on nutritional quality of eggs. Twenty-one of each of Amberlink and Hyline laying hens were fed on three diets for 30 days. Birds were distributed in a 3 × 2 factorial arrangement constituting three diets (0, 50 or 100 % of PABM) and two strains (Amberlink & Hyline). There was a diet × strain interaction on egg shell weight, average daily feed intake, egg production, egg weight and egg shell thickness. Eggs produced by layers under 100 % PABM had lighter eggshell weight and lower eggshell percentage. In contrast, eggs produced by layers under 50 % PABM diet had signi-ficantly higher eggshell percentage, heavier egg shell weight and thicker eggshell. As the level of PABM increased, the yellow and red hue (Hunter a* and b* values) significantly increased while the lightness values (Hunter L* values) decreased. As the level of PABM in the ration increased, the vitamin A content of the egg yolk also significantly increased. Assimilation of vitamin A from feed to egg yolk in Amberlink and Hyline hens was similar. Hence, egg enrichment with vitamin A can be achieved by using PABM in layers ration. The use of high level of PABM had a negative effect on the eggshell quality traits.

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The study was conducted to determine the interaction of types of maize (Provitamin A-biofortified maize (PABM) versus white maize) and strain of laying birds (Amberlink and Hyline) on nutritional quality of eggs. Twenty-one of each of Amberlink and Hyline laying hens were fed on three diets for 30 days. Birds were distributed in a 3 × 2 factorial arrangement constituting three diets (0, 50 or 100 % of PABM) and two strains (Amberlink & Hyline). There was a diet × strain interaction on egg shell weight, average daily feed intake, egg production, egg weight and egg shell thickness. Eggs produced by layers under 100 % PABM had lighter eggshell weight and lower eggshell percentage. In contrast, eggs produced by layers under 50 % PABM diet had signi-ficantly higher eggshell percentage, heavier egg shell weight and thicker eggshell. As the level of PABM increased, the yellow and red hue (Hunter a* and b* values) significantly increased while the lightness values (Hunter L* values) decreased. As the level of PABM in the ration increased, the vitamin A content of the egg yolk also significantly increased. Assimilation of vitamin A from feed to egg yolk in Amberlink and Hyline hens was similar. Hence, egg enrichment with vitamin A can be achieved by using PABM in layers ration. The use of high level of PABM had a negative effect on the eggshell quality traits.(AU)

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The goal of this research was to evaluate egg quality and performance of laying hens at the second laying cycle, fed with minerals from an organic source. The control treatment consisted of basal diet with inorganic trace minerals, whereas the other treatments consisted of organic copper, iron, manganese, and zinc at levels of 100%, 90%, 80%, and 70%. Physical and chemical analyses were performed to evaluate egg quality. The average egg weight reduced in the test diet; however, egg mass, as well as the other performance variables evaluated, did not suffer influence of treatments. The percentage of egg protein decreased; however, mineral matter content and egg shell increased with the use of organic minerals, as well as an improvement in the egg quality parameters occurred. The supplementation with organic trace mineral source of the diet of laying hens did not compromise internal egg quality. The total replacement of inorganic sources for levels of organic minerals in the diet of birds provided maintenance on the performance and improved shell quality.

Objetivou-se com esta pesquisa avaliar o desempenho produtivo e a qualidade de ovos de poedeiras em segundo ciclo de postura alimentadas com microminerais de fonte orgânica. O tratamento controle foi composto por dieta basal e microminerais inorgânicos e os demais tratamentos consistiram da inclusão dos microminerais cobre, ferro, manganês e zinco orgânicos, em substituição total à fonte inorgânica, em níveis de 100%, 90%, 80% e 70%. Análises físicas e bromatológicas foram realizadas para avaliar a qualidade dos ovos. O peso médio dos ovos diminuiu nas dietas teste; no entanto, a massa de ovos bem como as demais variáveis de desempenho avaliadas não sofreram influencia dos tratamentos. O percentual de proteína do ovo diminuiu; entretanto, a matéria mineral do conteúdo interno e casca aumentaram com o uso de minerais orgânicos, assim como houve melhora nos parâmetros de qualidade da casca. A suplementação de microminerais de fonte orgânica a dieta das poedeiras não comprometeu a qualidade interna dos ovos. A total substituição da fonte inorgânica por níveis de minerais orgânicos nas dietas das aves proporcionou manutenção no desempenho zootécnico e melhorias na qualidade de casca.

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The goal of this research was to evaluate egg quality and performance of laying hens at the second laying cycle, fed with minerals from an organic source. The control treatment consisted of basal diet with inorganic trace minerals, whereas the other treatments consisted of organic copper, iron, manganese, and zinc at levels of 100%, 90%, 80%, and 70%. Physical and chemical analyses were performed to evaluate egg quality. The average egg weight reduced in the test diet; however, egg mass, as well as the other performance variables evaluated, did not suffer influence of treatments. The percentage of egg protein decreased; however, mineral matter content and egg shell increased with the use of organic minerals, as well as an improvement in the egg quality parameters occurred. The supplementation with organic trace mineral source of the diet of laying hens did not compromise internal egg quality. The total replacement of inorganic sources for levels of organic minerals in the diet of birds provided maintenance on the performance and improved shell quality.(AU)

Objetivou-se com esta pesquisa avaliar o desempenho produtivo e a qualidade de ovos de poedeiras em segundo ciclo de postura alimentadas com microminerais de fonte orgânica. O tratamento controle foi composto por dieta basal e microminerais inorgânicos e os demais tratamentos consistiram da inclusão dos microminerais cobre, ferro, manganês e zinco orgânicos, em substituição total à fonte inorgânica, em níveis de 100%, 90%, 80% e 70%. Análises físicas e bromatológicas foram realizadas para avaliar a qualidade dos ovos. O peso médio dos ovos diminuiu nas dietas teste; no entanto, a massa de ovos bem como as demais variáveis de desempenho avaliadas não sofreram influencia dos tratamentos. O percentual de proteína do ovo diminuiu; entretanto, a matéria mineral do conteúdo interno e casca aumentaram com o uso de minerais orgânicos, assim como houve melhora nos parâmetros de qualidade da casca. A suplementação de microminerais de fonte orgânica a dieta das poedeiras não comprometeu a qualidade interna dos ovos. A total substituição da fonte inorgânica por níveis de minerais orgânicos nas dietas das aves proporcionou manutenção no desempenho zootécnico e melhorias na qualidade de casca. (AU)

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Abstract The goal of this research was to evaluate egg quality and performance of laying hens at the second laying cycle, fed with minerals from an organic source. The control treatment consisted of basal diet with inorganic trace minerals, whereas the other treatments consisted of organic copper, iron, manganese, and zinc at levels of 100%, 90%, 80%, and 70%. Physical and chemical analyses were performed to evaluate egg quality. The average egg weight reduced in the test diet; however, egg mass, as well as the other performance variables evaluated, did not suffer influence of treatments. The percentage of egg protein decreased; however, mineral matter content and egg shell increased with the use of organic minerals, as well as an improvement in the egg quality parameters occurred. The supplementation with organic trace mineral source of the diet of laying hens did not compromise internal egg quality. The total replacement of inorganic sources for levels of organic minerals in the diet of birds provided maintenance on the performance and improved shell quality.

Resumo Objetivou-se com esta pesquisa avaliar o desempenho produtivo e a qualidade de ovos de poedeiras em segundo ciclo de postura alimentadas com microminerais de fonte orgânica. O tratamento controle foi composto por dieta basal e microminerais inorgânicos e os demais tratamentos consistiram da inclusão dos microminerais cobre, ferro, manganês e zinco orgânicos, em substituição total à fonte inorgânica, em níveis de 100%, 90%, 80% e 70%. Análises físicas e bromatológicas foram realizadas para avaliar a qualidade dos ovos. O peso médio dos ovos diminuiu nas dietas teste; no entanto, a massa de ovos bem como as demais variáveis de desempenho avaliadas não sofreram influencia dos tratamentos. O percentual de proteína do ovo diminuiu; entretanto, a matéria mineral do conteúdo interno e casca aumentaram com o uso de minerais orgânicos, assim como houve melhora nos parâmetros de qualidade da casca. A suplementação de microminerais de fonte orgânica a dieta das poedeiras não comprometeu a qualidade interna dos ovos. A total substituição da fonte inorgânica por níveis de minerais orgânicos nas dietas das aves proporcionou manutenção no desempenho zootécnico e melhorias na qualidade de casca.

RESUMO

The experiment evaluated the effect of different calcium (Ca) levels in pre-laying and laying diets on the performance and egg quality of laying hens. Two hundred and fifty-six 16-week-old Brown Hisex pullets were housed in a conventional shed. The experiment had a completely randomized design with 4 x 2 factorial arrangement (four calcium levels - 0.8, 1.3, 1.8 and 2.3% in pre-laying phase; two calcium levels - 2.5 and 3.5% in laying phase), totaling eight treatments with four repetitions of eight birds per experimental unit. The experimentstarted with 16-week-old hens receiving pre-laying diets provided until they were 18 weeks old. At this period, the laying diets started. Four 28-day cycles were evaluated for the following variables: production and egg weight, feed intake, feed conversion, mass of eggs and eggshell quality. Results show that a good performance was obtained with 0.8% calcium level in the pre-laying phase, whereas in the laying phase the 3.5% calcium level provided greater weight egg and better eggshell quality.

O ensaio experimental objetivou avaliação do efeito de diferentes níveis de cálcio (Ca) nas rações de pré-postura e postura sobre o desempenho e qualidade dos ovos de poedeiras comerciais. Foram alojadas 256 frangas da linhagem Hisex Brown com 16 semanas de idade em galpão convencional de postura. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 4 x 2 (4 níveis de cálcio - 0,8; 1,3; 1,8 e 2,3% na pré-postura e 2 níveis de cálcio - 2,5 e 3,5% na postura), totalizando oito tratamentos com quatro repetições de oito aves por unidade experimental. Iniciou-se com a ração de pré-postura às 16 semanas de idade das aves, sendo que a mesma foi fornecida até as aves atingiram 18 semanas de idade, quando então, iniciou-se com a ração de postura. Foram avaliadas durante quatro ciclos de 28 dias as seguintes variáveis: produção e peso dos ovos,consumo de ração, conversão alimentar, massa de ovos e qualidade da casca dos ovos. Através dos resultados obtidos pode-se concluir que um bom desempenho foi obtido com 0,8% de cálcio na fase de pré-postura. Na fase de postura o nível de 3,5% de cálcio promoveu maior peso de ovo e melhor qualidade de casca.

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The experiment evaluated the effect of different calcium (Ca) levels in pre-laying and laying diets on the performance and egg quality of laying hens. Two hundred and fifty-six 16-week-old Brown Hisex pullets were housed in a conventional shed. The experiment had a completely randomized design with 4 x 2 factorial arrangement (four calcium levels - 0.8, 1.3, 1.8 and 2.3% in pre-laying phase; two calcium levels - 2.5 and 3.5% in laying phase), totaling eight treatments with four repetitions of eight birds per experimental unit. The experimentstarted with 16-week-old hens receiving pre-laying diets provided until they were 18 weeks old. At this period, the laying diets started. Four 28-day cycles were evaluated for the following variables: production and egg weight, feed intake, feed conversion, mass of eggs and eggshell quality. Results show that a good performance was obtained with 0.8% calcium level in the pre-laying phase, whereas in the laying phase the 3.5% calcium level provided greater weight egg and better eggshell quality.(AU)  

O ensaio experimental objetivou avaliação do efeito de diferentes níveis de cálcio (Ca) nas rações de pré-postura e postura sobre o desempenho e qualidade dos ovos de poedeiras comerciais. Foram alojadas 256 frangas da linhagem Hisex Brown com 16 semanas de idade em galpão convencional de postura. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 4 x 2 (4 níveis de cálcio - 0,8; 1,3; 1,8 e 2,3% na pré-postura e 2 níveis de cálcio - 2,5 e 3,5% na postura), totalizando oito tratamentos com quatro repetições de oito aves por unidade experimental. Iniciou-se com a ração de pré-postura às 16 semanas de idade das aves, sendo que a mesma foi fornecida até as aves atingiram 18 semanas de idade, quando então, iniciou-se com a ração de postura. Foram avaliadas durante quatro ciclos de 28 dias as seguintes variáveis: produção e peso dos ovos,consumo de ração, conversão alimentar, massa de ovos e qualidade da casca dos ovos. Através dos resultados obtidos pode-se concluir que um bom desempenho foi obtido com 0,8% de cálcio na fase de pré-postura. Na fase de postura o nível de 3,5% de cálcio promoveu maior peso de ovo e melhor qualidade de casca.(AU)

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Foi realizado um estudo sobre qualidade da casca dos ovos incubáveis provenientes de matrizes pesadas com diferentes idades, por meio da avaliação da relação entre peso da casca e peso do ovo e análises de peso específico, espessura, porosidade, resistência e microscopia eletrônica. Os dois tratamentos foram definidos pela idade da matriz, sendo considerados ovos de matrizes novas - 33 semanas - e de matrizes velhas - 63 semanas. Os ovos de matrizes com 33 semanas foram mais leves, e o número de poros por cm² foi menor que o de ovos das aves mais velhas. Ovos de aves com 63 semanas apresentaram menor percentual de casca em relação ao peso do ovo, menor peso específico e menores resistência e espessura da casca. A proporção das membranas da casca em relação à sua espessura total foi maior nas matrizes mais novas. Concluiu-se que ovos de matrizes velhas têm qualidade de casca inferior aos ovos das matrizes novas e que as membranas da casca nos ovos de matrizes novas desempenham papel relevante em sua estrutura.

We conducted a study on eggshell quality from Cobb® broiler breeders at different ages by assessing the relationship between eggshell weight and egg weight and analysis of specific weight, thickness, porosity, strength and electron microscopy. Both treatments were defined by broiler breeder age, considering eggs from young breeders (33 weeks) and eggs from old breeders (63 weeks). It was observed that eggs from breeders at 33 weeks have lower weight and number of pores per cm² compared with eggs from older birds. 63 weeks broiler breeders had lower percentage of eggshell in relation to egg weight, lower specific weight, strength and thickness, when compared with eggs from young breeders. The proportion of shell membranes in relation to its total thickness was significantly higher in young breeders. It was concluded that eggs from older broiler breeders have lower eggshell quality than the young breeders. The shell membranes in young breeder's eggs play a significant role in its structure, making it necessary to focus on this layer in future studies on eggshell quality and their relationship between breeder age and incubation yield.

Assuntos

RESUMO

Foi realizado um estudo sobre qualidade da casca dos ovos incubáveis provenientes de matrizes pesadas com diferentes idades, por meio da avaliação da relação entre peso da casca e peso do ovo e análises de peso específico, espessura, porosidade, resistência e microscopia eletrônica. Os dois tratamentos foram definidos pela idade da matriz, sendo considerados ovos de matrizes novas - 33 semanas - e de matrizes velhas - 63 semanas. Os ovos de matrizes com 33 semanas foram mais leves, e o número de poros por cm² foi menor que o de ovos das aves mais velhas. Ovos de aves com 63 semanas apresentaram menor percentual de casca em relação ao peso do ovo, menor peso específico e menores resistência e espessura da casca. A proporção das membranas da casca em relação à sua espessura total foi maior nas matrizes mais novas. Concluiu-se que ovos de matrizes velhas têm qualidade de casca inferior aos ovos das matrizes novas e que as membranas da casca nos ovos de matrizes novas desempenham papel relevante em sua estrutura.(AU)

We conducted a study on eggshell quality from Cobb® broiler breeders at different ages by assessing the relationship between eggshell weight and egg weight and analysis of specific weight, thickness, porosity, strength and electron microscopy. Both treatments were defined by broiler breeder age, considering eggs from young breeders (33 weeks) and eggs from old breeders (63 weeks). It was observed that eggs from breeders at 33 weeks have lower weight and number of pores per cm² compared with eggs from older birds. 63 weeks broiler breeders had lower percentage of eggshell in relation to egg weight, lower specific weight, strength and thickness, when compared with eggs from young breeders. The proportion of shell membranes in relation to its total thickness was significantly higher in young breeders. It was concluded that eggs from older broiler breeders have lower eggshell quality than the young breeders. The shell membranes in young breeder's eggs play a significant role in its structure, making it necessary to focus on this layer in future studies on eggshell quality and their relationship between breeder age and incubation yield.(AU)

Assuntos

RESUMO

The experiment was conducted with the aim to evaluate the effects of different levels of radish cake (0, 5, 10 and 20%) in laying hens rations on performance parameters and qualitative and sensorial characteristics of egg. A total of 240 light laying hens, with 52 to 60 weeks of age, standartized according the weight and laying performance distributed a completely randomized design, with six repetitions with eight birds per unit, were used. The experiment was conducted during eight weeks, subdivided within four periods of two weeks. There was effect of radish cake (P 0.05) for rations consumption, percentage of laying, egg mass, egg color parameters and sensorial avaluation. None differences were observed between the treatments for conversion rate and eggs weight. The use of radish cake to laying hens resulted a worst effects for performance parameters and sensorial egg characteristics.

O experimento foi conduzido com o objetivo de avaliar os efeitos da inclusão da torta de nabo forrageiro, TNBF, (0, 5, 10, 15 e 20%) na ração sobre os parâmetros produtivos e qualidade dos ovos de galinhas poedeiras. Foram utilizadas 240 poedeiras comerciais leves, entre 52 e 60 semanas de idade, uniformizadas por peso e postura, dispostas em um delineamento experimental inteiramente casualizado, com seis repetições de oito aves por tratamento. O experimento teve duração de oito semanas, dividido em quatro períodos de duas semanas cada. Houve efeito da TNBF (P 0,05) sobre o consumo de ração, porcentagem de postura, massa dos ovos, índices de cor e avaliação sensorial. Não houve efeito dos tratamentos para conversão alimentar e peso dos ovos. O uso da torta de nabo forrageiro na ração de galinhas poedeiras afeta negativamente os parâmetros produtivos e a qualidade sensorial dos ovos.

RESUMO

 The experiment was conducted with the aim to evaluate the effects of different levels of radish cake (0, 5, 10 and 20%) in laying hens rations on performance parameters and qualitative and sensorial characteristics of egg. A total of 240 light laying hens, with 52 to 60 weeks of age, standartized according the weight and laying performance distributed a completely randomized design, with six repetitions with eight birds per unit, were used. The experiment was conducted during eight weeks, subdivided within four periods of two weeks. There was effect of radish cake (P 0.05) for rations consumption, percentage of laying, egg mass, egg color parameters and sensorial avaluation. None differences were observed between the treatments for conversion rate and eggs weight. The use of radish cake to laying hens resulted a worst effects for performance parameters and sensorial egg characteristics.

O experimento foi conduzido com o objetivo de avaliar os efeitos da inclusão da torta de nabo forrageiro, TNBF, (0, 5, 10, 15 e 20%) na ração sobre os parâmetros produtivos e qualidade dos ovos de galinhas poedeiras. Foram utilizadas 240 poedeiras comerciais leves, entre 52 e 60 semanas de idade, uniformizadas por peso e postura, dispostas em um delineamento experimental inteiramente casualizado, com seis repetições de oito aves por tratamento. O experimento teve duração de oito semanas, dividido em quatro períodos de duas semanas cada. Houve efeito da TNBF (P 0,05) sobre o consumo de ração, porcentagem de postura, massa dos ovos, índices de cor e avaliação sensorial. Não houve efeito dos tratamentos para conversão alimentar e peso dos ovos. O uso da torta de nabo forrageiro na ração de galinhas poedeiras afeta negativamente os parâmetros produtivos e a qualidade sensorial dos ovos.