Leucine and valine supplementation of low-protein diets for broiler chickens from 21 to 42 days of age.

The objective of this study was to determine the requirements and interactions between the standardized ileal digestible (SID) Leu and Val levels in low-protein diets, and their effects on performance, serum characteristics, carcass yield and diameter of muscle fibers of broiler chickens from d 21 to 42 posthatch. A total of 1,500 21-day-old Cobb 500 male broiler chickens were distributed in a completely randomized design in a 5 × 5 factorial arrangement for a total of 25 treatments with 3 replicates of 20 birds each. Treatments consisted of 5 SID Leu levels (1.0, 1.2, 1.4, 1.6, or 1.8%) and 5 SID Val levels (0.52, 0.67, 0.82, 0.97, or 1.12%). At 42 d of age, there was interaction (P < 0.05) between the SID levels of Leu and Val on feed intake and weight gain. There was a quadratic effect (P < 0.05) of Leu and Val levels on feed conversion, with minimal point estimated at the levels of 1.19 and 0.86%, respectively. Dietary Leu supplementation reduced linearly (P < 0.05) serum concentrations of triglycerides and ß-hydroxybutyrate. Dietary Leu increased (P ≤ 0.05) the fiber diameters of the pectoralis major muscle and breast yield at the levels of 1.24 and 1.13%, respectively, while the thigh yield was improved with the level of 0.71% Val. Abdominal fat decreased linearly (P < 0.05) with increasing levels of dietary Leu and Val. The SID Leu and Val levels needed to optimize weight gain and feed conversion in low-CP diets for broiler chickens from d 21 to 42 posthatch were estimated at 1.15 and 0.86%, and 1.19 and 0.86%, respectively. The supplementation of Leu and Val can reduce the abdominal fat deposition in birds fed low-CP diets during the grower phase. Leu and Val interactions can influence the performance but not the serum characteristics, carcass yield and diameter of muscle fibers of broilers fed low-protein diets. Therefore, it is necessary to consider the dietary Leu content to estimate the ideal level of Val in low-CP diets for optimum broiler performance.

Physicochemical characteristics and lipid oxidation of chicken inner fillets subjected to different thermal processing types

The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments consisted in cooking in water bath, electric oven, microwave oven, deep frying, or grilling. The analyzed variables were: cooking weight loss (CWL) and lipid oxidation determined by thiobarbituric acid reactive substances (TBARS). In the second assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Each treatment consisted of the same cooking methods applied in the first assay, and storage for 48 hours under refrigeration and reheating in a microwave oven. The variable analyzed in the second assay was lipid oxidation (TBARS). In the third assay, 30 samples of chicken inner fillets were subjected to one, four and eight freeze-thaw cycles, after which meat pH, myofibrillar fragmentation index (MFI), water retention capacity (WRC), and lipid oxidation (TBARS) were determined. Chicken inner fillets submitted to deep frying and cooked in a microwave oven presented greater lipid oxidation than the other cooking methods, and deep frying resulted in the highest cooking weight loss. Reheating chicken inner fillets in a microwave oven caused the highest meat lipid oxidation. Increasing the number of freeze-thaw cycles increases the pH, MFI, WRC and TBARS values of chicken inner fillets.

Physicochemical characteristics and lipid oxidation of chicken inner fillets subjected to different thermal processing types

The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments consisted in cooking in water bath, electric oven, microwave oven, deep frying, or grilling. The analyzed variables were: cooking weight loss (CWL) and lipid oxidation determined by thiobarbituric acid reactive substances (TBARS). In the second assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Each treatment consisted of the same cooking methods applied in the first assay, and storage for 48 hours under refrigeration and reheating in a microwave oven. The variable analyzed in the second assay was lipid oxidation (TBARS). In the third assay, 30 samples of chicken inner fillets were subjected to one, four and eight freeze-thaw cycles, after which meat pH, myofibrillar fragmentation index (MFI), water retention capacity (WRC), and lipid oxidation (TBARS) were determined. Chicken inner fillets submitted to deep frying and cooked in a microwave oven presented greater lipid oxidation than the other cooking methods, and deep frying resulted in the highest cooking weight loss. Reheating chicken inner fillets in a microwave oven caused the highest meat lipid oxidation. Increasing the number of freeze-thaw cycles increases the pH, MFI, WRC and TBARS values of chicken inner fillets.(AU)

Minerais orgânicos e licopeno na alimentação de poedeiras: desempenho zootécnico e qualidade dos ovos / Organic minerals and lycopene in the diet of laying hens: production performance and egg quality

Objetivou-se avaliar o efeito da utilização de minerais orgânicos e do licopeno em rações para poedeiras sobre o desempenho zootécnico e a qualidade dos ovos. Utilizaram-se 288 poedeiras, distribuídas em DIC em esquema fatorial 2 x 3 (fontes de minerais x níveis de licopeno), com seis tratamentos, seis repetições e oito aves por unidade experimental. As rações experimentais foram: minerais inorgânicos (MI) sem a adição de licopeno; MI com a adição de licopeno (400mg/kg); MI com a adição de licopeno (800mg/kg); minerais orgânicos (MOR) sem a adição de licopeno; MOR com a adição de licopeno (400mg/kg); MOR com a adição de licopeno (800mg/kg). Foram avaliados: consumo de ração, porcentagem de postura, massa dos ovos, conversão alimentar (kg/kg e kg/dz), peso do ovo, porcentagens de casca, albúmen e gema, espessura da casca, gravidade específica, unidade Haugh, índice e coloração de gema, pH do albúmen e da gema. Os minerais orgânicos aumentam o consumo de ração quando associados a níveis de 0 e 800mg de licopeno. A associação de 400mg de licopeno com minerais inorgânicos aumenta o consumo de ração. A adição de minerais orgânicos ou de 400mg de licopeno às rações melhora a porcentagem de postura e massa dos ovos de poedeiras com 58 semanas de idade. A coloração de gema é mais acentuada para as fontes inorgânicas em relação às orgânicas e mais acentuada em rações com 800mg de licopeno. A unidade Haugh é maior em rações sem licopeno e com minerais inorgânicos e em rações com 400mg de licopeno e com minerais orgânicos. Rações com fonte orgânica associada a 800mg de licopeno proporcionam maior unidade Haugh em relação a fonte orgânica sem licopeno(AU)

This study aimed to evaluate the effect of the use of organic minerals and lycopene in the diet of laying hens on performance and egg quality. 288 hens were used, distributed in DIC in a factorial 2 x 3 (mineral sources x lycopene levels) with six treatments and six replicates of eight birds per experimental unit. The experimental diets were: inorganic minerals (MI) without the addition of lycopene; MI with the addition of lycopene (400mg/kg); MI with the addition of lycopene (800mg/kg); minerals organic (MOR) without addition lycopene; MOR with the addition of lycopene (400mg/kg); MOR with the addition of lycopene (800mg/kg). The following parameters were evaluated: feed intake, egg production, egg mass, feed conversion (kg/kg and kg/dz), egg weight, percentage shell, albumen and yolk, shell thickness specific gravity, unit Haugh, index and yolk color, pH of albumen and yolk. The organic minerals increase the feed intake when combined at levels of 0 and 800mg of lycopene. The combination of 400mg of lycopene with inorganic minerals increases feed intake. The addition of organic or mineral 400mg lycopene in diets improves egg production and egg weight of hens at 58 weeks of age. The yolk color is more pronounced for inorganic sources in relation to organic and more pronounced in diets with 800mg of lycopene. The Haugh unit is higher in lycopene free diets and diets with inorganic mineral and 400mg of lycopene and organic minerals. Diets with organic source associated with 800mg of lycopene provide higher Haugh units for organic source without lycopene(AU)

Minerais orgânicos e licopeno na alimentação de poedeiras: desempenho zootécnico e qualidade dos ovos / Organic minerals and lycopene in the diet of laying hens: production performance and egg quality

Objetivou-se avaliar o efeito da utilização de minerais orgânicos e do licopeno em rações para poedeiras sobre o desempenho zootécnico e a qualidade dos ovos. Utilizaram-se 288 poedeiras, distribuídas em DIC em esquema fatorial 2 x 3 (fontes de minerais x níveis de licopeno), com seis tratamentos, seis repetições e oito aves por unidade experimental. As rações experimentais foram: minerais inorgânicos (MI) sem a adição de licopeno; MI com a adição de licopeno (400mg/kg); MI com a adição de licopeno (800mg/kg); minerais orgânicos (MOR) sem a adição de licopeno; MOR com a adição de licopeno (400mg/kg); MOR com a adição de licopeno (800mg/kg). Foram avaliados: consumo de ração, porcentagem de postura, massa dos ovos, conversão alimentar (kg/kg e kg/dz), peso do ovo, porcentagens de casca, albúmen e gema, espessura da casca, gravidade específica, unidade Haugh, índice e coloração de gema, pH do albúmen e da gema. Os minerais orgânicos aumentam o consumo de ração quando associados a níveis de 0 e 800mg de licopeno. A associação de 400mg de licopeno com minerais inorgânicos aumenta o consumo de ração. A adição de minerais orgânicos ou de 400mg de licopeno às rações melhora a porcentagem de postura e massa dos ovos de poedeiras com 58 semanas de idade. A coloração de gema é mais acentuada para as fontes inorgânicas em relação às orgânicas e mais acentuada em rações com 800mg de licopeno. A unidade Haugh é maior em rações sem licopeno e com minerais inorgânicos e em rações com 400mg de licopeno e com minerais orgânicos. Rações com fonte orgânica associada a 800mg de licopeno proporcionam maior unidade Haugh em relação a fonte orgânica sem licopeno.

This study aimed to evaluate the effect of the use of organic minerals and lycopene in the diet of laying hens on performance and egg quality. 288 hens were used, distributed in DIC in a factorial 2 x 3 (mineral sources x lycopene levels) with six treatments and six replicates of eight birds per experimental unit. The experimental diets were: inorganic minerals (MI) without the addition of lycopene; MI with the addition of lycopene (400mg/kg); MI with the addition of lycopene (800mg/kg); minerals organic (MOR) without addition lycopene; MOR with the addition of lycopene (400mg/kg); MOR with the addition of lycopene (800mg/kg). The following parameters were evaluated: feed intake, egg production, egg mass, feed conversion (kg/kg and kg/dz), egg weight, percentage shell, albumen and yolk, shell thickness specific gravity, unit Haugh, index and yolk color, pH of albumen and yolk. The organic minerals increase the feed intake when combined at levels of 0 and 800mg of lycopene. The combination of 400mg of lycopene with inorganic minerals increases feed intake. The addition of organic or mineral 400mg lycopene in diets improves egg production and egg weight of hens at 58 weeks of age. The yolk color is more pronounced for inorganic sources in relation to organic and more pronounced in diets with 800mg of lycopene. The Haugh unit is higher in lycopene free diets and diets with inorganic mineral and 400mg of lycopene and organic minerals. Diets with organic source associated with 800mg of lycopene provide higher Haugh units for organic source without lycopene.

Lisina digestível em dietas de baixa proteína para frangos de corte tipo caipira de um aos 28 dias / Digestible lysine in diets containing low protein concentrations for broiler type redneck from 1 to 28 days

Avaliou-se a inclusão de diferentes porcentagens de lisina digestível em dietas de baixa proteína para frangos de corte tipo caipira, machos e fêmeas, com idade entre um e 28 dias. Utilizaram-se 792 machos e 792 fêmeas de linhagem comercial, de um dia de idade, distribuídos em delineamento inteiramente ao acaso, em esquema fatorial 2x6 (sexo x porcentagem de lisina digestível: 0,85; 0,90; 0,95; 1,00; 1,05 e 1,10%) com seis repetições de 22 aves. Não foi constatada interação (P>0,05) de sexo versus inclusão de lisina. Observou-se superioridade (P<0,05) dos machos em relação às fêmeas para todas as variáveis avaliadas. O ganho de peso dos frangos diminuiu linearmente (P<0,05) em função do aumento da porcentagem de lisina digestível na dieta e observou-se redução linear (P<0,01) nos consumos de ração e de proteína. O consumo de lisina digestível aumentou linearmente (P<0,01) em função do aumento de sua concentração na dieta. Não houve diferença (P>0,05) para conversão alimentar. Da composição centesimal da carcaça, apenas o percentual de matéria mineral foi influenciada (P<0,05) pela porcentagem de lisina digestível. Conclui-se que 0,85% de lisina para frangos tipo caipira de pescoço pelado atende à exigência nutricional de lisina digestível em dietas com baixa concentração proteica.

The inclusion of different percentages of digestible lysine in low-protein diets was evaluated for male and female free-range broiler chickens, from 1 to 28 days. We used 792 female and 792 male naked neck chickens a day in a completely randomized 2x6 factorial scheme (sex x percentages of digestible lysine: 0.85, 0.90, 0.95, 1.00, 1.05 and1.10%) with six replicates of 22 broilers. No interaction of sex versus lysine was found. Superiority was observed (P<0.05) in males compared to females for all variables.Weight gainof chickens decreased linearly(P<0.05) with increasing levels of digestible lysine in the diet. There was a linear reduction (P<0.01) in feed intake, protein and metabolizable energy. On the other hand, the consumption of digestible lysine increased linearly (P<0.01) with the increase of its concentration in the diet. There was nodifference (P>0.05) in food conversion.In the chemical composition of the carcass, only thepercentage of mineral matter was influenced (P<0.05) bydigestible lysine levels.It was concluded that the level of 0.85% for type redneck broiler meets the nutritional requirement of digestible lysine in diets containing lower protein concentrations.

Lisina digestível em dietas de baixa proteína para frangos de corte tipo caipira de um aos 28 dias / Digestible lysine in diets containing low protein concentrations for broiler type redneck from 1 to 28 days

Avaliou-se a inclusão de diferentes porcentagens de lisina digestível em dietas de baixa proteína para frangos de corte tipo caipira, machos e fêmeas, com idade entre um e 28 dias. Utilizaram-se 792 machos e 792 fêmeas de linhagem comercial, de um dia de idade, distribuídos em delineamento inteiramente ao acaso, em esquema fatorial 2x6 (sexo x porcentagem de lisina digestível: 0,85; 0,90; 0,95; 1,00; 1,05 e 1,10%) com seis repetições de 22 aves. Não foi constatada interação (P>0,05) de sexo versus inclusão de lisina. Observou-se superioridade (P<0,05) dos machos em relação às fêmeas para todas as variáveis avaliadas. O ganho de peso dos frangos diminuiu linearmente (P<0,05) em função do aumento da porcentagem de lisina digestível na dieta e observou-se redução linear (P<0,01) nos consumos de ração e de proteína. O consumo de lisina digestível aumentou linearmente (P<0,01) em função do aumento de sua concentração na dieta. Não houve diferença (P>0,05) para conversão alimentar. Da composição centesimal da carcaça, apenas o percentual de matéria mineral foi influenciada (P<0,05) pela porcentagem de lisina digestível. Conclui-se que 0,85% de lisina para frangos tipo caipira de pescoço pelado atende à exigência nutricional de lisina digestível em dietas com baixa concentração proteica.(AU)

The inclusion of different percentages of digestible lysine in low-protein diets was evaluated for male and female free-range broiler chickens, from 1 to 28 days. We used 792 female and 792 male naked neck chickens a day in a completely randomized 2x6 factorial scheme (sex x percentages of digestible lysine: 0.85, 0.90, 0.95, 1.00, 1.05 and1.10%) with six replicates of 22 broilers. No interaction of sex versus lysine was found. Superiority was observed (P<0.05) in males compared to females for all variables.Weight gainof chickens decreased linearly(P<0.05) with increasing levels of digestible lysine in the diet. There was a linear reduction (P<0.01) in feed intake, protein and metabolizable energy. On the other hand, the consumption of digestible lysine increased linearly (P<0.01) with the increase of its concentration in the diet. There was nodifference (P>0.05) in food conversion.In the chemical composition of the carcass, only thepercentage of mineral matter was influenced (P<0.05) bydigestible lysine levels.It was concluded that the level of 0.85% for type redneck broiler meets the nutritional requirement of digestible lysine in diets containing lower protein concentrations.(AU)

Effect of arginine on the development of the pectoralis muscle and the diameter and the protein:deoxyribonucleic acid rate of its skeletal myofibers in broilers.

This work aimed at evaluating the effects of the supplementation of starter diet with Arg on breast muscle development in broilers and the activation of satellite cells and the aggregation of myofibrillar protein. Male Cobb chicks (n = 990) were randomly assigned to 1 of 5 treatments in a complete random design. Measurements of 33 chicks per treatment were made in 6 repetitions. The treatments consisted of a basal diet with 1.390% digestible Arg (without supplementation) and 4 dietary levels of Arg (1.490, 1.590, 1.690, and 1.790%) with Arg:Lys ratios of 1.103, 1.183, 1.262, 1.341, and 1.421, respectively. Arginine supplementation was used only in the starter phase (1 to 21 d). Dietary supplementation with Arg had a positive effect (P < 0.05) on breast and breast fillet weight on d 7 and 21 and on myofiber diameter on d 14 and 21. However, no effect was observed (P > 0.05) on the protein:DNA ratio, which demonstrates that Arg does not interfere with the mitotic activity of the satellite cells. Independently from mechanism, Arg affected muscle growth in the starter phase positively. Dietary supplementation with Arg in the starter phase had no effect (P > 0.05) on the carcass yield of broilers on d 42. Diet supplementation with Arg at levels above the ones recommended for the starter phase may be necessary for improved muscle development in broilers.