Supplementation of broiler breeders with fat sources and vitamin e: carry over effect on performance, carcass yield, and meat quality offspring / Suplementação de matrizes de frangos de corte com fontes de gordura e vitamina E: transferência dos efeitos sobre a performance, o rendimento da carcaça e a qualidade da carne da progênie

The aim of this study was to evaluate two sources of oil (soybean and fish) and four additional levels of vitamin E (0, 150, 250 and 350mg/kg diet) in breeder diets between the 42nd and 56th week of age and its effect on performance and meat quality of offspring. The supplementation of fish oil in the maternal diet increased the deposition of DHA and CLA in egg yolk. From 1 to 35 days of age, intermediate levels of vitamin E resulted in lower weight gain and feed intake. To feed conversion, the best result was obtained supplementing the maternal diet with soybean oil, regardless of vitamin inclusion. In addition, the evaluation of meat quality, the fish oil-supplemented-diet resulted in lower moisture loss of the breast fillets. For maternal diet supplemented with fish oil, the inclusion of vitamin E resulted in a linear increase of the pH value of the meat. Greater levels of vitamin E in the maternal diet influenced the functional properties of meat according to the type of oil that was added to the diet. The deposition of different fatty acids in the embryonic egg yolk can directly influence the meat quality of offspring.(AU)

O objetivo deste estudo foi avaliar duas fontes de óleo (soja e peixe) e quatro níveis adicionais de vitamina E (0, 150, 250 e 350mg/kg dieta), em dietas de matrizes entre a 42º e a 56º semana de idade, sobre o desempenho e a qualidade de carne da progênie. A suplementação de óleo de peixe na dieta das matrizes aumentou a deposição de DHA e CLA na gema dos ovos. Entre um e 35 dias de idade, níveis intermediários de vitamina E resultaram em menor ganho de peso e consumo de ração. Para a conversão alimentar, o melhor resultado foi obtido suplementando a dieta materna com óleo de soja, independentemente da inclusão vitamínica. Dietas suplementadas com óleo de peixe resultaram em menor perda de umidade nos filés de peito. Para a dieta materna suplementada com óleo de peixe, a inclusão de vitamina E resultou em um aumento linear do valor de pH da carne. Níveis mais altos de vitamina E na dieta materna influenciaram as propriedades funcionais da carne de acordo com o tipo de óleo adicionado à dieta. A deposição de diferentes ácidos graxos na gema de ovos embrionados pode influenciar diretamente a qualidade da carne da progênie.(AU)

Supplementation of broiler breeders with fat sources and vitamin e: carry over effect on performance, carcass yield, and meat quality offspring / Suplementação de matrizes de frangos de corte com fontes de gordura e vitamina E: transferência dos efeitos sobre a performance, o rendimento da carcaça e a qualidade da carne da progênie

The aim of this study was to evaluate two sources of oil (soybean and fish) and four additional levels of vitamin E (0, 150, 250 and 350mg/kg diet) in breeder diets between the 42nd and 56th week of age and its effect on performance and meat quality of offspring. The supplementation of fish oil in the maternal diet increased the deposition of DHA and CLA in egg yolk. From 1 to 35 days of age, intermediate levels of vitamin E resulted in lower weight gain and feed intake. To feed conversion, the best result was obtained supplementing the maternal diet with soybean oil, regardless of vitamin inclusion. In addition, the evaluation of meat quality, the fish oil-supplemented-diet resulted in lower moisture loss of the breast fillets. For maternal diet supplemented with fish oil, the inclusion of vitamin E resulted in a linear increase of the pH value of the meat. Greater levels of vitamin E in the maternal diet influenced the functional properties of meat according to the type of oil that was added to the diet. The deposition of different fatty acids in the embryonic egg yolk can directly influence the meat quality of offspring.(AU)

O objetivo deste estudo foi avaliar duas fontes de óleo (soja e peixe) e quatro níveis adicionais de vitamina E (0, 150, 250 e 350mg/kg dieta), em dietas de matrizes entre a 42º e a 56º semana de idade, sobre o desempenho e a qualidade de carne da progênie. A suplementação de óleo de peixe na dieta das matrizes aumentou a deposição de DHA e CLA na gema dos ovos. Entre um e 35 dias de idade, níveis intermediários de vitamina E resultaram em menor ganho de peso e consumo de ração. Para a conversão alimentar, o melhor resultado foi obtido suplementando a dieta materna com óleo de soja, independentemente da inclusão vitamínica. Dietas suplementadas com óleo de peixe resultaram em menor perda de umidade nos filés de peito. Para a dieta materna suplementada com óleo de peixe, a inclusão de vitamina E resultou em um aumento linear do valor de pH da carne. Níveis mais altos de vitamina E na dieta materna influenciaram as propriedades funcionais da carne de acordo com o tipo de óleo adicionado à dieta. A deposição de diferentes ácidos graxos na gema de ovos embrionados pode influenciar diretamente a qualidade da carne da progênie.(AU)

Digestible valine requirements in low-protein diets for broilers chicks

Three experiments were carried out to evaluate the levels of digestible valine in diets with reduced crude protein on the performance, carcass yield and muscle fiber diameter of male broilers during the pre-starter (1 to 8 d of age), starter (9 to 21 d of age) and grower phases (21 to 42 d of age). A total of 1,080 chickens in the pre-starter phase, 900 in the starter phase and 864 in the grower phase were distributed in a completely randomized design with six treatments, consisting of a control positive diet (C+) and diets with 2 percentage points (p.p.) reduction of crude protein level and five graded levels of digestible valine (Val), with six replicates of 30, 25 and 24 birds per experimental unit, respectively. The recommended level of TID Val in the low-protein diets for broilers in the pre-starter, starter and grower stages were 1.028; 0.905 and 0.789%, respectively. The reduction of 2 percentage points of the crude protein level in diets based on corn and soybean meal impaired (p 0.05) carcass and parts yields, or abdominal fat percentage at 42 days.

Digestible valine requirements in low-protein diets for broilers chicks

Three experiments were carried out to evaluate the levels of digestible valine in diets with reduced crude protein on the performance, carcass yield and muscle fiber diameter of male broilers during the pre-starter (1 to 8 d of age), starter (9 to 21 d of age) and grower phases (21 to 42 d of age). A total of 1,080 chickens in the pre-starter phase, 900 in the starter phase and 864 in the grower phase were distributed in a completely randomized design with six treatments, consisting of a control positive diet (C+) and diets with 2 percentage points (p.p.) reduction of crude protein level and five graded levels of digestible valine (Val), with six replicates of 30, 25 and 24 birds per experimental unit, respectively. The recommended level of TID Val in the low-protein diets for broilers in the pre-starter, starter and grower stages were 1.028; 0.905 and 0.789%, respectively. The reduction of 2 percentage points of the crude protein level in diets based on corn and soybean meal impaired (p <= 0.05) the feed conversion ratio in the starter and grower stages. Likewise, the reduced-protein diets decreased (p <= 0.05) muscle fiber diameter, but did not affect (p> 0.05) carcass and parts yields, or abdominal fat percentage at 42 days.(AU)

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.(AU)

The effect of arginine dietary supplementation in broiler breeder hens on offspring humoral and cell-mediated immune responses

The influence of supplementing the diet of broiler breeder hens with arginine (Arg) on their offspring's humoral and cell-mediated immune response was evaluated in two experiments. In experiments I and II, breeder hens were fed diets containing graded levels of Arg (0.943, 1.093, 1.243, 1.393 and 1.543% digestible Arg). In experiment I, the offspring was randomly grouped according to the treatment received by the breeder hens, with five levels of Arg in the maternal diet and six replicates, giving a total 30 experimental units. In experiment II, the offspring were grouped in accordance with the treatment received by the breeder hens; however, Arg was added to the starter diet (1.300, 1.450, 1.600, 1.750 and 1.900% digestible Arg) and also the growing diet (1.150, 1.300, 1.450, 1.600 and 1.750% digestible Arg). Supplementation of the broiler breeder hen diet did not influence (p > 0.05) the development of the lymphoid organs (cloacal bursa, thymus and spleen) of the offspring, whether their diet were supplemented or not. Nevertheless, greater weight and dimensions cloacal bursa were found in the supplemented offspring in comparison with the nonsupplemented offspring. Macrophage phagocytic activity was found to be unaffected (p > 0.05), independently of the Arg supplementation. The offspring fed with supplemented diets showed a linear reduction in the antibody titer against Newcastle Disease (p 0.05) by the breeder hen diet. This study concluded that supplementing the breeder hen diet with arginine is insufficient to improve the humoral and cellular immune response, requiring supplementation of the offspring diet.

Sources of trophic action on performance and intestinal morphometry of broiler chickens vaccinated against coccidiosis

The aim of this experiment was to evaluate the effect of sources of trophic action (glutamine alone, glutamine associated with glutamic acid and yeast) associated with vaccination against coccidiosis on the performance and morphometry of the small intestine of broilers. In the trial, 1,200 broiler chicks were distributed according to a completely randomized design with a 3 x 2 + 2 (trophic action x vaccination or not + control - free trophic factor) factorial arrangement, with five replicates of 30 birds each. Vaccination negatively affected performance parameters and the morphometry of the intestinal mucosa, but at the end of the experimental period, among the broilers vaccinated against coccidiosis, the group fed glutamine presented better recovery from epithelial losses of the intestinal mucosa compared with the control groups. Therefore, the dietary supplementation with the evaluated sources of trophic action could be a strategy to enhance the development of broilers submitted to vaccine stress, also considering the economic viability of the productive segment.

Sources of trophic action on performance and intestinal morphometry of broiler chickens vaccinated against coccidiosis

The aim of this experiment was to evaluate the effect of sources of trophic action (glutamine alone, glutamine associated with glutamic acid and yeast) associated with vaccination against coccidiosis on the performance and morphometry of the small intestine of broilers. In the trial, 1,200 broiler chicks were distributed according to a completely randomized design with a 3 x 2 + 2 (trophic action x vaccination or not + control - free trophic factor) factorial arrangement, with five replicates of 30 birds each. Vaccination negatively affected performance parameters and the morphometry of the intestinal mucosa, but at the end of the experimental period, among the broilers vaccinated against coccidiosis, the group fed glutamine presented better recovery from epithelial losses of the intestinal mucosa compared with the control groups. Therefore, the dietary supplementation with the evaluated sources of trophic action could be a strategy to enhance the development of broilers submitted to vaccine stress, also considering the economic viability of the productive segment.(AU)

The effect of arginine dietary supplementation in broiler breeder hens on offspring humoral and cell-mediated immune responses

The influence of supplementing the diet of broiler breeder hens with arginine (Arg) on their offspring's humoral and cell-mediated immune response was evaluated in two experiments. In experiments I and II, breeder hens were fed diets containing graded levels of Arg (0.943, 1.093, 1.243, 1.393 and 1.543% digestible Arg). In experiment I, the offspring was randomly grouped according to the treatment received by the breeder hens, with five levels of Arg in the maternal diet and six replicates, giving a total 30 experimental units. In experiment II, the offspring were grouped in accordance with the treatment received by the breeder hens; however, Arg was added to the starter diet (1.300, 1.450, 1.600, 1.750 and 1.900% digestible Arg) and also the growing diet (1.150, 1.300, 1.450, 1.600 and 1.750% digestible Arg). Supplementation of the broiler breeder hen diet did not influence (p > 0.05) the development of the lymphoid organs (cloacal bursa, thymus and spleen) of the offspring, whether their diet were supplemented or not. Nevertheless, greater weight and dimensions cloacal bursa were found in the supplemented offspring in comparison with the nonsupplemented offspring. Macrophage phagocytic activity was found to be unaffected (p > 0.05), independently of the Arg supplementation. The offspring fed with supplemented diets showed a linear reduction in the antibody titer against Newcastle Disease (p < 0.05) at seven days of age, and a quadratic response (p < 0.05) at 28 days of age. The antibody titer in the non-supplemented offspring was not influenced (p > 0.05) by the breeder hen diet. This study concluded that supplementing the breeder hen diet with arginine is insufficient to improve the humoral and cellular immune response, requiring supplementation of the offspring diet.(AU)

Effect of different vitamin D sources and calcium levels in the diet of layers in the second laying cycle

This study evaluated the effects of different sources of vitamin D and calcium levels on performance, egg quality and bone strength of hens in the second production cycle. A total of 384 Hy-Line W36 birds with 80 weeks of age were used, alloted into 3 x 4 factorial design (sources of vitamin D: cholecalciferol; 25(OH)D3 and 1.25(OH)2D3 x calcium levels: 2.85, 3.65; 4.45 and 5.25%) with four replicates and eight birds each. The performance was evaluated for three cycles of 28 days each, egg quality was evaluated in the last four days of each cycle and bone strength on the last day of the experimental period. There was no interaction (p > 0.05) between the different sources of vitamin D and calcium levels in all parameters evaluated. There was a quadratic effect (p 0.05) in the egg weight and Haugh unit, but there was a linear increase (p < 0.05) in the percentage and eggshell thickness, in specific gravity and bone strength. The different sources of vitamin D influenced (p < 0.05) the egg production rate, feed conversion, egg weight and Haugh unit. Thus, the results of this study suggest that the recommended calcium level for laying on second cycle is between 4.09% and 4.14% and that the metabolites cholecalciferol and 25(OH)D3 improved the performance and egg quality. Regarding bone strength was improved as the calcium levels were increased in diets.

Mixed crude glycerin in laying hen diets: live performance and egg quality and fatty acid profile

This study evaluated the performance and the quality and fatty acid profile of eggs from laying hens fed diets containing mixed crude glycerin (MCG; 80% vegetable fat + 20% animal fat). A total of 240 39-week-old Hy-Line W36 laying hens were distributed according to a completely randomized experimental design into six treatments consisting of graded MCG dietary inclusion levels (0, 1.5, 3.0, 4.5, 6.0, and 7.5%), with five replicates of eight birds each. Feed intake linearly decreased (p 0.05) with increasing MCG inclusion levels. The percentages of myristic, palmitic, and -linolenic acids in the eggs linearly decreased as MCG dietary levels increased (p 0.05), while -linoleic acid, polyunsaturated fatty acids (PUFA) and -6/-3 ratio linearly increased. Excreta moisture linearly increased with increasing levels of MCG inclusion (p 0.05). MCG may be included in up to 7.5% in layer feeds without impairing performance or egg quality, but levels up to 5.54% reduce SFA egg content. However, the inclusion of MCG in layer diets increases -6/-3 ratio in the eggs.

Mixed crude glycerin in laying hen diets: live performance and egg quality and fatty acid profile

This study evaluated the performance and the quality and fatty acid profile of eggs from laying hens fed diets containing mixed crude glycerin (MCG; 80% vegetable fat + 20% animal fat). A total of 240 39-week-old Hy-Line W36 laying hens were distributed according to a completely randomized experimental design into six treatments consisting of graded MCG dietary inclusion levels (0, 1.5, 3.0, 4.5, 6.0, and 7.5%), with five replicates of eight birds each. Feed intake linearly decreased (p 0.05) with increasing MCG inclusion levels. The percentages of myristic, palmitic, and -linolenic acids in the eggs linearly decreased as MCG dietary levels increased (p 0.05), while -linoleic acid, polyunsaturated fatty acids (PUFA) and -6/-3 ratio linearly increased. Excreta moisture linearly increased with increasing levels of MCG inclusion (p 0.05). MCG may be included in up to 7.5% in layer feeds without impairing performance or egg quality, but levels up to 5.54% reduce SFA egg content. However, the inclusion of MCG in layer diets increases -6/-3 ratio in the eggs.(AU)

Effect of different vitamin D sources and calcium levels in the diet of layers in the second laying cycle

This study evaluated the effects of different sources of vitamin D and calcium levels on performance, egg quality and bone strength of hens in the second production cycle. A total of 384 Hy-Line W36 birds with 80 weeks of age were used, alloted into 3 x 4 factorial design (sources of vitamin D: cholecalciferol; 25(OH)D3 and 1.25(OH)2D3 x calcium levels: 2.85, 3.65; 4.45 and 5.25%) with four replicates and eight birds each. The performance was evaluated for three cycles of 28 days each, egg quality was evaluated in the last four days of each cycle and bone strength on the last day of the experimental period. There was no interaction (p > 0.05) between the different sources of vitamin D and calcium levels in all parameters evaluated. There was a quadratic effect (p < 0.05) of calcium levels in egg production and feed conversion (kg/kg and kg/dz), with better results at levels of 4.12%, 4.09% and 4.14%, respectively. Calcium levels had no effect (p > 0.05) in the egg weight and Haugh unit, but there was a linear increase (p < 0.05) in the percentage and eggshell thickness, in specific gravity and bone strength. The different sources of vitamin D influenced (p < 0.05) the egg production rate, feed conversion, egg weight and Haugh unit. Thus, the results of this study suggest that the recommended calcium level for laying on second cycle is between 4.09% and 4.14% and that the metabolites cholecalciferol and 25(OH)D3 improved the performance and egg quality. Regarding bone strength was improved as the calcium levels were increased in diets.(AU)

Desempenho produtivo e reprodutivo de matrizes de frangos de corte com dietas suplementadas com vitamina E, óleo de soja e óleo de peixe / Productive and reproductive performance of broiler breeders with diets supplemented with vitamin E and soybean and fish oil

No experimento, foram avaliados duas fontes de óleo (soja e peixe) e quatro níveis suplementares de vitamina E (0, 150, 250 e 350 mg/kg de ração) em dietas de matrizes de frangos de corte da linhagem Ross, entre a 42ª e a 56ª semana de idade. A adição de óleo de soja teve efeito no peso de ovos, quando não houve inclusão de vitamina E. A suplementação de 215,96 mg de vitamina E/kg de dieta em dietas com óleo de soja aumentou o percentual de postura. A adição de níveis crescentes de vitamina E acima das exigências, independentemente da fonte de óleo utilizada, melhorou a fertilidade. Não houve efeito para peso dos pintos, eclodibilidade, mortalidade e número de espermatozoides na membrana vitelínica ou em valores métricos de testículos.(AU)

Two sources of oil (soybean and fish) and four supplemental levels of vitamin E (0, 150, 250 and 350 mg/kg diet) in diets of Ross broilers breeders, between the 42 and 56 weeks of age, were evaluated. The addition of soybean oil had an effect on egg weight, when there was no inclusion of vitamin E. Supplementation of 215.96 mg vitamin E/kg diet in diets with soybean oil increased the laying percentage. The increasing levels of vitamin E above requirements, regardless of source of oil used, improved fertility. There was no effect on chick weight, hatchability, mortality and number of spermatozoidsin the vitelline membrane or metric values of testicles.(AU)

Desempenho produtivo e reprodutivo de matrizes de frangos de corte com dietas suplementadas com vitamina E, óleo de soja e óleo de peixe / Productive and reproductive performance of broiler breeders with diets supplemented with vitamin E and soybean and fish oil

No experimento, foram avaliados duas fontes de óleo (soja e peixe) e quatro níveis suplementares de vitamina E (0, 150, 250 e 350 mg/kg de ração) em dietas de matrizes de frangos de corte da linhagem Ross, entre a 42ª e a 56ª semana de idade. A adição de óleo de soja teve efeito no peso de ovos, quando não houve inclusão de vitamina E. A suplementação de 215,96 mg de vitamina E/kg de dieta em dietas com óleo de soja aumentou o percentual de postura. A adição de níveis crescentes de vitamina E acima das exigências, independentemente da fonte de óleo utilizada, melhorou a fertilidade. Não houve efeito para peso dos pintos, eclodibilidade, mortalidade e número de espermatozoides na membrana vitelínica ou em valores métricos de testículos.

Two sources of oil (soybean and fish) and four supplemental levels of vitamin E (0, 150, 250 and 350 mg/kg diet) in diets of Ross broilers breeders, between the 42 and 56 weeks of age, were evaluated. The addition of soybean oil had an effect on egg weight, when there was no inclusion of vitamin E. Supplementation of 215.96 mg vitamin E/kg diet in diets with soybean oil increased the laying percentage. The increasing levels of vitamin E above requirements, regardless of source of oil used, improved fertility. There was no effect on chick weight, hatchability, mortality and number of spermatozoidsin the vitelline membrane or metric values of testicles.

Effects of dietary arginine supplementation on broiler breeder egg production and hatchability

This study investigated the effects of arginine (Arg) supplementation on broiler breeder egg production and egg quality. Male (30) and female (360) Ross® breeders, totaling 390 birds, were studied. A completely randomized design with five Arg levels (0.943%, 1.093%, 1.243%, 1.393%, 1.543% digestible Arg) and six replicates of 12 females and one male per experimental unit was applied. The following performance and egg quality were evaluated: lay percentage, albumen and yolk contents, average egg weight, egg specific gravity, and eggshell percentage and thickness. Hatchability and and embryo mortality were also determined. The applied dietary digestible Arg levels quadratically influenced egg production (p<0.05), with the highest production obtained when 1.262% digestible Arg was supplemented. Egg weight linearly increased (p<0.05) with digestible Arg dietary level; however, egg specific gravity linearly decreased (p<0.05). Hatchability was not affected (p<0.05) by digestible Arg level. The supplementation of broiler breeder diets with Arg improved egg production and egg weight without any effect on hatchability. Further research is needed to determine the effect of dietary Arg supplementation on the performance of the progeny.(AU)

Quantidade de metionina+cistina digestível para poedeiras semipesadas de 75 a 91 semanas de idade / Nutritional requirement of digestible methionine + cystine for brown-egg laying hens from 75 to 91weeks of age

Determinaram-se as exigências nutricionais de metionina+cistina digestível para poedeiras de linhagem comercial no segundo ciclo de produção de 75 a 91 semanas de idade, utilizando-se 150 aves semipesadas em delineamento inteiramente ao acaso. Estas foram distribuídas em cinco tratamentos, seis repetições e cinco aves por unidade experimental, alimentadas com uma dieta basal contendo 2.859kcal/kg de energia metabolizável e 16,30% de proteína bruta, suplementada com 0,132; 0,173; 0,215; 0,256 e 0,298% de DL-metionina (98%), de forma a proporcionar 0,588; 0,628; 0,669; 0,709 e 0,750% de metionina+cistina digestível na dieta. A inclusão de metionina+cistina obedeceu, respectivamente, às proporções de 67, 72, 77, 81 e 86% com a lisina fixada em 0,872%. Avaliaram-se os consumos de ração e de metionina+cistina, a conversão alimentar por dúzia e por massa de ovos, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos e o ganho de peso. A inclusão de metionina+cistina digestível nas quantidades indicadas não exerceu efeito (P>0,05) sobre as características de produção e qualidade interna e externa dos ovos. A exigência estimada foi de 0,588% de metionina+cistina digestível, correspondendo ao consumo de 654,73mg/ave/dia.(AU)

This work determined the nutritional requirements for methionine + cystine for commercial hens in the second production cycle from 75 to 91 weeks of age, using 150 brown-egg layer hens in a completely randomized design, distributed in five treatments, six replicates of five hens each and fed a basal diet containing 2859kcal/kg of metobolizable energy, 16.30% crude protein supplemented with 0.132, 0.173, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.588, 0.628, 0.669, 0.709 and 0.750% methionine + cystine in the diet. The inclusion of methionine + cystine followed, respectively, the proportions of 67, 72, 77, 81 and 86% with lysine fixed at 0.872%. The feed intake, methionine + cystine intake, feed conversion per dozen eggs and egg mass, percentage of the eggs, egg weight, egg mass, percentage of egg components and internal quality of eggs and weight gain were evaluated. The inclusion methionine + cystine in the amounts indicated had no effect (P> 0.05) on the production characteristics and internal and external quality of eggs. The requirement was estimated at 0.588% methionine + cystine intake corresponding to 654.73mg/hen/day.(AU)