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 β-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.

This work studied the effect of supplementing commercially available amino acids in low-protein diets using different ratios of digestible (dig) glycine+serine:lysine (Gly+Ser:Lys) on performance, serum parameters, feathering, and litter characteristics of broiler chickens during the starter period. A total of one thousand fifty 1-d-old Cobb-Vantress male chicks were distributed in a completely randomized experimental design into 6 treatments with 5 replicates of 35 birds each. The treatments were as follows: T1, control diet based on corn and soybean meal formulated with 22% CP (dig Gly+Ser:Lys ratio of 147); T2, diet with a 2% CP reduction, supplemented with Val (dig Gly+Ser:Lys ratio of 137); T3, similar to T2 with the addition of Gly (dig Gly+Ser:Lys ratio of 147); T4, diet with a 3% CP reduction, supplemented with Val, Ile, and Arg (dig Gly+Ser:Lys ratio of 127); and T5 and T6, similar to T4 with the addition of Gly (dig Gly+Ser:Lys ratios of 137 and 147, respectively). At 7 and 21 d, broilers that had received diets with a 3% CP reduction (19% CP) and a Gly+Ser:Lys ratio that was equivalent to 127 had lower G:F (P < 0.05) and lower total protein and albumin serum concentrations (P < 0.05) than those broilers that received the control feed. However, these parameters were restored to the same level as the control diet with an increase in the dig Gly+Ser:Lys ratio from 127 to 137 and 147. Diets with a 3% CP reduction (19% CP) resulted in litter with reduced (P < 0.05) nitrogen content and lower ammonia emission than the litter of broilers receiving the control diet. The treatments did not influence (P > 0.05) the feather length or feathering scores at 21 or 28 d of age. The supplementation of essential amino acids while maintaining dig Gly+Ser:Lys ratios at and above 137 allowed for a reduction in the dietary CP of 3% without undermining the performance, feathering or serum parameters of early stage broilers.

Experimental power is a measure of the ability of an experiment to detect differences between treatment means. Researchers design experiments and then calculate the probability that differences are simply due to chance, the null hypothesis. The objective of the analyses reported here was to determine the appropriate number of samples to demonstrate significant differences of various magnitudes from broiler chicken blood constituents. Over 800 samples were taken for a study of the effects of sample storage time, serum vs. plasma, light intensity, and fed vs. fasted birds on blood cholesterol, triglycerides, uric acid, glucose, total protein (TP), albumin, globulin, alanine aminotransferase (ALT), aspartate aminotransferase, gammaGT, creatinine, alkaline phosphatase, Ca and P. Various transformations increased the QQ plot R2 values from 0.000 to 0.149 or 0.00 to 17.62%. Most of the QQ plot R2 values were at or above 0.90. The 1/x2 transformation of blood P data showed the biggest increase in QQ plot R2 (0.846 to 0.995). The different standard deviations and coefficients of variation (CVs) found for each variable resulted in widely different numbers of replicates needed to detect differences in 2 treatment means. The extremes were glucose with a CV of 6.9% and ALT with a CV of 39.7%. For glucose, 15 replicates are needed to find a 10% difference in 97% of experiments; for ALT, 15 replicates would detect a 50% difference 91% of the time. The use of parameters such as cholesterol, glucose, TP, albumin, and globulin showed low CVs, indicating they may be considered as stable parameters. The lower CVs make it possible to find differences with a smaller number of replicates used in studies. As reported, the phosphorus values did not have a normal distribution of the data, so a transformation of these data could be an alternative to better discuss the results found.

RESUMO. Objetivou-se com este trabalho avaliar o efeito de aditivos promotores de crescimento (prebiótico, probiótico e simbiótico) em substituição ao antibiótico sobre o desempenho e características de carcaça (cortes nobres, órgãos e gordura abdominal), em dietas para frangos de corte de um a 42 dias de idade. Foram utilizados 384 pintos de um dia de idade alojados sobre cama reutilizada. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro tratamentos e seis repetições, sendo: PROsuplementação com probiótico (2 kg t -1 ), ANT -suplementação com antibióticos (flavomicina 10% -4 ppm e halquinol 60% -15 ppm), PRE -suplementação com prebiótico (5 kg t -1 ), SIMB -suplementação com probiótico e prebiótico (2 e 5 kg t -1 , respectivamente). O probiótico utilizado era composto por Lactobacillus acidophillus; Streptococcus faecium e Bifidobacterium bifidum e o prebiótico utilizado foi inulina (extrato de raiz de chicória). Na fase inicial, os frangos alimentados com dietas contendo probiótico e simbiótico tiveram maior ganho de peso e peso total aos 21 dias. A suplementação na ração com antibiótico proporcionou menor consumo de ração de um a 21 dias de idade. Os promotores de crescimento não apresentaram efeito sobre as variáveis de desempenho, rendimento de carcaça e cortes nobres estudadas na fase de um a 42 dias de idade.Palavras-chave: antibiótico, desempenho, prebiótico, simbiótico.ABSTRACT. Evaluation of inulin and probiotic for broiler chickens. The objective of this work was to evaluate the effects of growth promoter additives (prebiotic, probiotic and symbiotic) as an antibiotic replacement on the performance and carcass characteristics (prime cuts, organs and abdominal fat) in diets for broiler chickens 1 to 42 days old. A total of 384 birds were used, one-day-old, on a reused bed. A completely randomized design was used, with four treatments and six replications, namely: PRO -supplementation with probiotic (2 kg t -1 ), ANT -supplementation with antibiotics (flavomycin 10% -4 ppm and halquinol 60% -15 ppm), PRE -supplementation with prebiotic (5 kg t -1 ), SIMBsupplementation with probiotic and prebiotic (2 and 5 kg t -1 , respectively). The probiotic used consisted of Lactobacillus acidophilus, Streptococcus faecium and Bifidobacterium bifidum, and the prebiotic used consisted of inulin (chicory root extract). In the initial phase, the chickens fed diets containing probiotic and symbiotic had higher weight gain and total weight at 21 days. Supplementation with antibiotics in feed provided a lower feed intake at 1 to 21 days old. The growth promoters did not show an effect on the variables of performance, carcass yield and prime cuts studied in the phase from 1 to 42 days of age.Key words: antibiotic, performance, prebiotic, symbiotic. IntroduçãoA avicultura vem buscando a excelência em produção animal, aliado ao baixo custo e excelente qualidade dos produtos reunindo os diversos conhecimentos nas áreas de sanidade, genética, manejo e nutrição, a fim de atender à demanda e às ex...

RESUMO -Um experimento foi conduzido com o objetivo de estabelecer a exigência nutricional de metionina + cistina (met + cist) para poedeiras semipesadas no segundo ciclo de produção. Utilizaram-se 180 poedeiras semipesadas no período de 79 a 95 semanas de idade alimentadas com uma ração basal deficiente em met + cist (0,490%) suplementada com 0,00; 0,053; 0,108; 0,161; e 0,214% de DL-metionina (98%), de forma a proporcionar 0,490; 0,542; 0,594; 0,648; e 0,698% de met + cist digestível. Os níveis de suplementação de met + cist obedeceram, respectivamente, às relações de 75, 83, 91, 99 e 107 com lisina. O delineamento experimental foi o inteiramente casualizado com cinco níveis de met + cist, seis repetições e seis aves por unidade experimental. Avaliaram-se os consumos de ração e de met + cist, a conversão alimentar por dúzia e por massa de ovos, o ganho de peso, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos. Os níveis de met + cist tiveram efeito linear positivo sobre a conversão alimentar por dúzia de ovos, efeito quadrático sobre o consumo de ração, o ganho de peso e a conversão alimentar. Os níveis de met + cist tiveram efeito linear positivo sobre a taxa de postura e efeito quadrático sobre o peso e a massa de ovos. Observaram-se ainda efeito quadrático sobre a unidade Haugh e efeito linear sobre o índice de gema. A exigência de met + cist é igual ou superior a 0,698%, que corresponde a consumo mínimo de 786 mg de met + cist digestível/ave.dia.Palavras-chave: aminoácido, produção de ovos, qualidade de ovos Nutrition levels of digestible methionine + cystine for brown-egg laying hens in the 2 nd production cycle ABSTRACT -An experiment study was carried out to establish the nutritional requirement of methionine + cystine (met + cyst) for brown-egg laying hens, in the second production cycle. One hundred and eighty Lohmann Brown birds from 79 and 95 weeks of age were used fed a base diet deficient in met + cyst, supplemented with 0.00; 0.053; 0.108; 0.161 and 0.214% DL-Methionine (98%), providing 0.490; 0.542; 0.594; 0.648 and 0.698% digestible met + cyst. The levels supplementation of met + cyst followed the lysine relations (0.653%) of 75, 83, 91, 99 and 107. A complete randomized design with five levels of met + cyst, six replications/treatment and six birds per experimental unit was used.The feed intake, met + cyst intake, feed conversion per dozen eggs and egg mass, weight gain, egg production, egg weight, egg mass, percentage of the egg components and the internal quality of the eggs were evaluated. A positive linear effect was obtained for food conversion per dozen eggs. A quadratic effect was observed of the met + cyst levels on diet intake, weight gain and food conversion. The met + cyst levels had a positive linear effect on the laying rate and quadratic effect on egg weight and mass. A quadratic effect was also observed of the on the Haugh unit and linear effect on yolk index.The requirement of met + cyst is higher or equal to 0.6...

ObjectiveThis study was to evaluate the sunflower cake and enzymatic complex fed to broilers from 22 to 42 d of age.MethodsIn a completely randomized design, a total of 850 birds were allotted in a 2×5 factorial scheme (with and without enzymatic complex) and five inclusion levels (0%, 5%, 10%, 15%, 20%) of sunflower cake. There were 5 replications and 17 birds in each experimental unit. Data from performance, carcass yield and intestinal morphology were evaluated.ResultsFeed intake, weight gain, final weight and feed:gain ratio linearly worsened as sunflower cake increased. For weight gain, final weight and feed:gain ratio, the birds whose diets contained levels of 15% and 20% of sunflower cake showed worse values (p<0.05) than the birds fed the control diet. When fed the enzymatic complex, birds improved (p<0.05) crypt depth and villus:crypt ratio in the jejunum. As inclusion levels of sunflower cake increased, villus depth and villus:crypt ratio in duodenum, jejunum and ileum linearly reduced and the crypt depth linearly increased. Carcass yield linearly reduced as sunflower cake increased.ConclusionBased on performance, sunflower cake can be used up to 10% in broilers feeding from 21 to 42 days of age.

-This study was carried out to evaluate the effect of supplementation of probiotics (Lactobacillus acidophilus, Enterococcus faecium and Bifidubacterium bifidum) and antibiotics (flavomicina and staquinol) on diets for broilers from 1 to 42 days of age, reared in clean (new litter) and challenged (reused litter) environments. A total of 768 one-day-old male broilers of the Cobb 500 strain were distributed in a completely randomized design in a 2 × 4 factorial arrangement (2 litter types × 4 diets), totaling eight treatments with eight replications and 16 poultry per experimental unit. The results of performance and carcass characteristics were submitted to analysis of variance using the Studen Newman Keuls test at 0.05 probability. In the period of 1-21 days of age, the supplementation with probiotics for poultry raised in the new litter reduced feed intake, whereas in those raised in reused litter, the diet free of growth promoter showed a lower consumption. Poultry from 1 to 42 days raised in new litter had lower feed intake when supplemented with probiotics. Other results of performance and carcass yield were not affected. For the poultry raised in reused litter, the use of probiotics resulted in lower thigh yield and higher liver yield. The use of different growth promoters in feed for broilers does not influence the performance of poultry raised in new or reused litter. The use of probiotic promotes lower feed intake without compromising the performance, regardless of the type of litter used, demonstrating the feasibility of using this product as substitute for antibiotics.

The objective of this study was to evaluate the inclusion of dry residue of cassava (DRC) with or without supplementation of carbohydrases on performance, carcass yield, cuts and organs, blood parameters and meat quality of broiler chickens. Birds were distributed in a completely randomised design in a 2 x 5 factorial scheme, with or without addition of carbohydrases and five levels of DRC inclusion, resulting in 10 treatments with 5 replicates of 22 birds each. At 21 days of age, two birds of each treatment were fasted for 6 hours for blood brachial puncture. At 42 days, four birds per pen were slaughtered to determine carcass yield, cuts, organs, percentage of abdominal fat and meat quality. Between 1-21 days of age, there was an interaction (P < 0.05) between carbohydrase and DRC supplementation on weight gain (WG) and feed intake, which showed a decreasing linear effect without the inclusion of carbohydrases. In the period from 1 to 42 days, there was an interaction (P < 0.05) between carbohydrase supplementation and DRC inclusion on the variables WG and feed conversion. Carbohydrase inclusion provided an increase (P < 0.05) in the concentrations of cholesterol, triglycerides, creatinine, gamma GT and blood glucose. Concentrations of gamma GT were increased and levels of alanine aminotransferase and creatinine were decreased (P < 0.05) with DRC inclusion. At 24 hours post mortem, there was a significant interaction (P < 0.05) for breast meat between carbohydrase supplementation and DRC inclusion for the variable L. The analysed values of pH, water holding capacity and shear force of the breast meat were not affected (P > 0.05) by DRC inclusion and carbohydrase addition. However, cooking loss was influenced (P < 0.05) by levels of inclusion of DRC. The L and a* variable and the feet of broiler chickens were not affected (P > 0.05) by DRC levels and carbohydrase addition. The colour variable b* showed a decrease (P < 0.05) from 5% level of inclusion. The results of this study show that DRC can be used in the diets of broiler chickens from 1 to 21 days old to the assessed level of 10%, provided that carbohydrase is added. ResumoO objetivo do trabalho foi avaliar a inclusão do resíduo seco de fecularia (RSF) com ou sem a suplementação de carboidrases sobre o desempenho, o rendimento de carcaça, cortes e órgãos, parâmetros sanguíneos e qualidade da carne de frangos de corte. As aves foram distribuídas em um delineamento inteiramente casualizado, em esquema fatorial 2x5, constituído da combinação da adição ou não de carboidrases e cinco níveis de inclusão de RSF, resultando em 10 tratamentos, com cinco repetições de 22 aves cada. Aos 21 dias de idade, duas aves por unidade experimental foram mantidas em jejum por 6 horas, para coleta de sangue via punção braquial. Aos 42 dias de idade, quatro aves por unidade experimental foram abatidas para determinação do rendimento de carcaça, cortes, órgãos, porcentagem de gordura abdominal e avaliação da qualidade da carne. No período de 1 a 21 dias de idade houve in...