ABSTRACT The objective of this study was to estimate the nutritional requirement of digestible methionine + cystine for Japanese quail during the growth phase and its residual effect on the laying phase. One experiment was conducted, including three phases: starter, from 1 to 14 days of age; grower, from 15 to 42 days of age; and laying, from 43 to 168 days of age. The experimental design was entirely randomized with five treatments (0.52, 0.64, 0.76, 0.88, and 1.00% of digestible methionine + cystine) and five replicates. In starter phase, 48 quail/experimental unit (box) were used; in grower phase, 31 quail/experimental unit (box) were used, which were reared until 14 days old, receiving conventional feed and, in laying phase, 12 quail/experimental unit were selected from grower phase to evaluate the residual effect. To evaluate animal performance, feed intake (g/bird), body weight (g), weight gain (g), feed conversion (g/g), and viability (%) were analyzed. At 14 and 42 days of age, the relative weight (%) of liver, spleen, and cloacal pouch organs, the birds’ warping (%) and body chemical composition (%) were evaluated. During laying, performance and egg quality were evaluated. In the starter and grower stages, quadratic effects were observed for all performance variables. Laying performance results confirmed the estimates obtained in the grower phase; however, there was no effect on egg quality. Considering the best feed conversion, the nutritional recommendation of digestible methionine + cystine for Japanese quail in the starter phase is 0.85% and in the grower phase, it is 0.77%, corresponding to daily intake of 50.43 and 158.5 mg of digestible methionine + cystine/day, respectively.

Abstract An experiment was carried out with Japanese quails in the initial laying phase, from 43 to 168 days of age, to determine the nutritional requirement of digestible methionine + cystine for this period. 375 quails were used, being fifteen quails used per experimental unit. A total of 5 treatments (0.60, 0.75, 0.90, 1.05 and 1.20% digestible methionine + cystine) were used in a completely randomized design with 5 replicates each. The performance parameters evaluated were feed intake (g / bird), body weight (g), egg weight (g), laying rate (%), egg mass (g eggs.bird.day-1), feed conversion by mass and dozen eggs (g.g-1 of eggs, g.dz-1 of eggs), viability (%) and the body chemical composition (%). The egg quality parameters were: % of component (yolk, albumen and shell relative to egg weight), specific gravity (g mL-1), Haugh unit, yolk index, shell weight per surface area and thickness of the shell (mm). Quadratic effect was found on the performance parameters evaluated (P<0.05), except for age at first egg and viability with linear effect. Regarding egg quality, no significant effect was observed on the variables tested (P>0.05). The nutritional recommendation of digestible methionine + cystine for Japanese quails at laying phase is 0.90% from the maximum point obtained for the egg mass, egg weight and laying rate, corresponding to daily intake of 241.54 mg of digestible methionine + cystine / day, respectively.

Resumo Foi desenvolvido um experimento com codornas japonesas na fase inicial de postura, de 43 a 168 dias de idade, com o objetivo de determinar a exigência nutricional de metionina + cistina digestível para este período. Foram utilizadas 375 codornas, sendo 15 aves por unidade experimental. O delineamento experimental foi inteiramente casualizado (DIC) totalizando 5 tratamentos (0,60; 0,75; 0,90; 1,05 e 1,20 % de metionina + cistina digestível) com 5 repetições cada. As variáveis de desempenho avaliadas foram, consumo de ração (g/ave), peso corporal (g), peso do ovo (g), taxa de postura (%), produção de massa de ovos (g ovos.ave. dia-1), conversão alimentar por massa e dúzia de ovos (g.g-1 de ovos, g.dz-1 de ovos), viabilidade (%) e a composição química corporal (%). As variáveis de qualidade dos ovos foram, percentagem do componente (gema, albúmen e casca em relação ao peso do ovo), gravidade específica (g mL.-1), unidade Haugh, índice de gema e peso da casca por superfície de área. Foi encontrado efeito quadrático sobre as variáveis de desempenho avaliadas (P<0,05), exceto para idade ao primeiro ovo e viabilidade que apresentaram efeito linear. Em relação à qualidade dos ovos, não foi observado efeito significativo sobre as variáveis testadas (P>0,05). A recomendação nutricional de metionina + cistina digestível para codornas japonesas na fase de postura é de 0,90% a partir do ponto de máxima obtido para as variáveis massa de ovos, peso de ovos e taxa de postura, correspondendo ao consumo diário de 241,54 mg de metionina + cistina digestível / dia, respectivamente.

ABSTRACT The objective of this study was to evaluate the effect of the supplementation of two xylanases in the diet of meat-type quail on performance, morphology of the intestinal mucosa, metabolization of nutrients, and carcass yield. The experimental design was a completely randomized 2×3+1 factorial arrangement [two metabolisable energy reductions (70 and 140 kcal/kg), with or without the inclusion of two xylanases (A and B), plus a control treatment without xylanase), totalling seven treatments with five replicates and 42 quail each. Total excreta were collected at 28 days of age to determine the metabolisable coefficients of dry matter, crude protein (CP), neutral detergent fibre (NDF), and gross energy (GE). There was no interaction between the energetic reductions and inclusion of xylanases on performance variables of the birds. The 70 kcal/kg reduction led to better results for feed intake, weight gain, and feed conversion, while the 140 kcal/kg reduction led to worse results. In terms of jejunum morphometry, there was no interaction between energy reductions and inclusion of xylanases, although xylanases increased villi height and villus:crypt ratio. There was an interaction between energy reduction and inclusion of enzymes for the metabolisability coefficients of CP, NDF, and GE, leading to improvements in these coefficients. Xylanases A and B are effective in energy-reduced corn and soybean meal diets for 15 to 35-day-old quail.

ABSTRACT The objective of this study was to estimate the growth parameters of body weight and body nutrient deposition in males and females of one meat- (Coturnix coturnix coturnix) and two laying-type quail strains (Coturnix coturnix japonica), designated either yellow or red, using the Gompertz model. A total of 1350 quail from 1 to 42 days of age were used and they were distributed in a completely randomized design, with five replications for each strain. The parameters of body weight and body composition of the quail were analyzed weekly and evaluated using the Gompertz equation; growth rates and body nutrient deposition were evaluated through derivative equations. The three strains evaluated showed differences in their potential, growth rates, and body chemical composition. The composition up to 42 days of age was not sufficient to adjust the fat deposition data using Gompertz. Due to the period evaluated, the Gompertz model allowed to verify that females have higher body growth rates when compared with males of the same strains, with accelerated growth up to 14 and 21 days of age for males and females, respectively. Regarding the laying strain, the red has greater growth, with similar potential in depositing protein and water in the carcass, but they are more precocious in the deposition of these nutrients.

ABSTRACT The objective of this study was to determine the adjustment quality of non-linear models and estimate the growth parameters and body chemical composition of a meat-type quail strain (Coturnix coturnix coturnix) and two laying quail strains (Coturnix coturnix japonica), designated yellow and red. The study used 1500 quail, not sexed, distributed in a completely randomized design with three treatments and five repetitions. The experimental period was from 1-42 days of age. The birds were raised in a conventional system and fed ad libitum with a diet formulated to meet their nutritional requirements. Quail were weighed weekly, and a representative sample was slaughtered to evaluate their body chemical composition. The adjustment quality of the models was evaluated by means of the residual mean square (RMS), regression residue squares sum (SSRR), and number of iterations required for convergence. In evaluating the adjustment quality for the body weight of the three strains, the Gompertz, Logistic, and Von Bertalanffy models gave good fit, with Gompertz providing the best adjustment among them. For body composition, the Gompertz and Logistic models were the best, with Gompertz showing a slight superiority. Gompertz is the best model for describing growth curves and body chemical composition of body weight, protein, water, and ash in meat-type quail. In addition, it is the best model for describing growth curves and body chemical composition of body weight of yellow laying quail and of body weight, protein, and ash in red laying quail. Logistic was the best model for describing growth curves and body chemical composition of water, protein, and ash in yellow laying quail, and of water in red laying quail.

RESUMO Objetivou-se avaliar a biometria das vísceras e os parâmetros sanguíneos de codornas de corte aos 14 e 35 dias de idade, suplementadas com diferentes níveis de selênio inorgânico e vitamina E. Utilizou-se um delineamento inteiramente casualizado, em esquema fatorial 4×4 (Se inorgânico = 0,1125; 0,2250; 0,3375 e 0,4500 mg/kg de ração x VE = 10; 23; 36 e 49 UI/kg de ração). No experimento de 0 a 14 dias, foram utilizadas 2.400 codornas recémnascidas, distribuídas em 16 tratamentos e três repetições de 50 aves cada. No experimento de 14 a 35 dias, sob os mesmos tratamentos, foram utilizadas 1.680 codornas com 14 dias de idade e três repetições de 35 aves cada. Aos 14 dias, o pesos relativo de baço (P=0,0203) aumentou linearmente em função dos níveis de VE, enquanto aos 35 dias, o peso relativo de bolsa cloacal (P=0,0390) aumentou linearmente em função do Se. Aos 14 dias, verificou-se interação (P=0,0097) vitamínica x mineral nas concentrações de colesterol total (CT), além de efeito quadrático (P=0,0138) relacionado aos níveis de Se e redução linear (P=0,0275) em função da VE. Aos 35 dias, as concentrações de CT (P=0,0055) e triglicerídeos (TGR, P=0,0220) apresentaram efeito quadrático para o Se. O aumento linear do peso do baço e bolsa cloacal aos 14 e 35 dias respectivamente, sugerem melhora na resposta imune em função da suplementação de VE e Se. Para a mínima concentração de CT e TGR aos 35 dias de idade, recomenda-se a suplementação de 0,26 e 0,29 mg/Se/kg/ração respectivamente.

SUMMARY This study aimed to evaluate biometric viscera and blood parameters of quails at 14 and 35 days of age, supplemented with different levels of inorganic selenium and vitamin E. A completely randomized design was used in a 4×4 factorial scheme (inorganic Se = 0.1125, 0.2250, 0.3375 and 0.4500 mg/kg diet x VE = 10, 23, 36 and 49 IU/kg feed). In the 0-14 days experiment, 2,400 newborn quail were used, distributed in 16 treatments and three replications of 50 birds each. In the 14-35 days experiment, 1,680 14 day-old quails were used with same treatments and three replicates of 35 birds each. At 14 days, the relative spleen weights (P=0.0203) increased linearly as a function of the VE level, while at 35 days, the relative weight of the bursa (P=0.0390) increased linearly as a function of Se concentration. At 14 days, there was a vitamin x mineral interaction (p=0.0097) affecting total cholesterol (TC), and a quadratic effect (P = 0.0138) related to Se and linear reduction levels (P=0.0275) as a function of VE. At 35 days, the TC concentrations (P=0.0055) and triglycerides (TG, P = 0.0220) showed a quadratic effect for Se. The linear increase in spleen weight and bursa after 14 and 35 days respectively suggests an improved immune response as a function of VE and Se supplementation. To achieve the lowest concentration of TC and TG at 35 days of age, supplementation of 0.26 and 0.29 mg/Se/kg/feed, respectively, is recommended.

ABSTRACT An experiment was conducted to estimate the parameters of the Gompertz, Brody, Logistic, and Von Bertalanffy equations through Bayesian inference and evaluate the potential for growth in terms of weight and body composition of laying female quail (Coturnix coturnix japonica). The weights and body compositions of the birds were obtained weekly (1-119 days), allowing the adjustment of the four equations by Bayesian inference. The parameters mature weight (β1), integration constant (β2), maturity rate (β3), and their credibility intervals in four models on body weight and body components were properly estimated by Bayesian inference to describe the body growth in laying quail. The inflection point was determined by the 1st and 2nd derivatives of the Gompertz equation for body weight and body components (fat, protein, ash, and water). Based on Deviance Information Criterion (DIC) for the studied and analyzed variables, there is a model that fits best as a result of its better performance to achieve the DIC value. The Von Bertalanffy model proved to be very versatile, not obtaining good fit of data only for fat. The study shows that other models can also be used in several data sets as an alternative to Gompertz, which, due to its adequate biological interpretation and desirable characteristics in a curve growth, is generally the most used.

ABSTRACT An experiment was conducted to determine the required levels of supplementary vitamin D and calcium in meat-type quail (Coturnix coturnix sp) between 15 and 35 days old. The experiment was a 4 × 4 factorial design with four levels of calcium: 0.42, 0.58, 0.74, and 0.90% and four levels of vitamin D: 1,000; 2,000; 3,000; and 4,000 IU. Body weight and body weight gain increased linearly and feed conversion showed some linear improvement due to increased levels of Ca and vitamin D. The increased vitamin D levels resulted in a linear increase in feed intake. Calcium and vitamin D requirements in meat-type quail between 15 and 35 days of age is greater or equal to 0.90% Ca and greater or equal to 4,000 IU of vitamin D, probably because the experiment was conducted during the pre-laying phase.

RESUMO Objetivou-se com este estudo, determinar a composição química, a energia metabolizável aparente (EMA), energia metabolizável aparente corrigida para o nitrogênio (EMAn) e a metabolizabilidade da matéria seca (MS), proteína bruta (PB), extrato etéreo (EE) e fibra em detergente neutro (FDN) do farelo da semente de maracujá (FSM) para codornas. Foram utilizadas 100 codornas de corte (Coturnix coturnix japonica) com 21 dias de idade, distribuídos em um delineamento inteiramente casualizado, com quatro tratamentos, cinco repetições e quatro aves por unidade experimental. Os tratamentos constituíram de diferentes níveis de FSM (4,0; 8,0; 12,0; 16,0%) em substituição a ração referência. Valores metabolizáveis foram determinados por ajuste de equações lineares. O FSM pode ser caracterizado como um alimento alternativo para codornas de corte e seus principais compostos são a energia bruta (5.569 kcal kg-1), PB (11,34%), EE (18,84%) e FDN (50,22%), na matéria natural. Foram ajustadas as equações EMA = 2.976 + 5,877 x (r2 = 0,94) e EMAn = 2.939 + 4,864 x (r2 = 0,95), assim, a EMA e EMAn foram estimadas em 2.976 e 2.939 kcal kg-1, respectivamente. Adicionalmente, foram ajustadas equações para PB, EE, FDN e MS resultando em valores metabolizáveis de 6,35, 17,9, 12,48 e 45,66%, respectivamente. Conclui-se que os principais componentes do farelo da semente de maracujá são a energia bruta, proteína bruta, extrato etéreo e fibra em detergente neutro, e a EMA e EMAn para codornas de corte é de 2.976 e 2.939 kcal kg-1, respectivamente.

SUMMARY The objective of this study was to determine the chemical composition, apparent metabolizable energy (AME), apparent metabolizable energy corrected for nitrogen balance (AMEn) and the metabolizability of dry matter (DM), crude protein (CP), ether extract (EE) and neutral detergent fiber (NDF) of passion fruit seed meal (PFM) for quails. One hundred meat quails (Coturnix coturnix japonica), with 21 days old, allotted in a completely randomized design, with four treatments, five replicates and four animals per experimental unit. The treatments consisted of different levels PFM (4.0, 8.0, 12.0 and 16.0%) that replaced the basal diet (w/w). Metabolizable values were determined by fitting linear equations the PFM can be characterized as an alternative feedstuff for meat quails and the main chemical compounds are gross energy (5,569 kcal kg-1), CP (11.34%), EE (18.84%) and NDF (50.22%), as fed basis. Linear equations were fitted as follow: AME = 2,976 x + 5.877 (r2 = 0.94) and AMEn = 2,939 x + 4.864 (r2 = 0.95), thus AME and AMEn were estimated at 2,976 and 2,939 kcal kg-1, respectively. Additionaly, equations were adjusted for CP, EE, NFD and DM, respectively resulting in a metabolization of 6.35, 17.9, 12.48 and 45.66%. It is concluded that main components of the passion fruit seed meal are gross energy, crude protein, ether extract and neutral detergent fiber and its AME and AMEn for meat quails are 2,976 and 2,939 kcal kg-1, respectively.

El objetivo de este experimento fue evaluar la calidad interna del huevo de las gallinas ponedoras (Hy-line W36), en dos edades diferentes (37 y 69 semanas), con 6 periodos de almacenamiento (1, 7, 14, 21, 28 y 35 día), dos condiciones de almacenamiento (habitación y refrigerador) y dos tipos de embalaje de huevos (con y sin película plástica); asignado a un estudio aleatorizado en un factorial (2 x 6 x 2 x 2). Los parámetros analizados fueron: altura de la albúmina, la pérdida de peso relativo del huevo, la gravedad específica y Haugh unidad (UH). Los huevos almacenados en una nevera y una menor edad de las gallinas ponedoras dieron lugar a una mejor preservación de la calidad interna del huevo. El tipo de embalaje no ha aportado ningún cambio en la calidad interna en los distintos tipos de almacenamiento.

Quality of eggs of laying hens in two ages under different storage conditions and type of egg carton

O objetivo deste experimento foi de avaliar a qualidade interna de ovos de poedeiras comerciais (Hy- line W36), em duas idades diferentes (37 e 69 semanas), com 6 períodos de estocagem (1, 7, 14, 21, 28 e 35 dias), duas condições de armazenamento (ambiente e geladeira) e dois tipos de embalagem de ovos ( com e sem plástico filme); distribuídos em delineamento ao acaso em esquema fatorial (2 x 6 x 2 x 2). Os parâmetros analisados foram: altura de albúmen, perda de peso relativo dos ovos, gravidade específica e unidade Haugh (UH). O armazenamento dos ovos em geladeira e a menor idade das poedeiras proporcionaram melhor conservação da qualidade interna dos ovos. O tipo de embalagem não proporcionou nenhuma alteração na qualidade interna nos diferentes tipos de armazenamento.

Desempeño y rendimiento en carcasa y piezas de tres diferentes líneas de codornices

The objective of this study was to evaluate the performance and yield of the carcass and parts (wing, thigh and drumstick, back and chest) of males and females of a meat-type quail strain (Coturnix coturnix sp.) and two strains of laying quails (Coturnix coturnix japonica) called yellow and red. 1350 birds were used, one to 42 days of age, distributed in a completely randomized design, with five repetitions for each line. The birds were fed ad libitum with diets formulated to meet its nutritional requirements. The performance was evaluated weekly and the parts and carcass yield at 35 and 42 days of age. The meat-type strain showed higher body weight, average weight gain, feed conversion, biomass accumulated body of a 14 day of age carcass yield at 35 days and chest at 35 and 42 days. Among the laying quails, red obtained better results for weight gain, feed conversion and yield wing after 42 days of age. The gender effect was observed for yield wing and back to 35 days of age to 42 days and breast. It is verifi ed that the three evaluated quail strains showed higher body accumulated biomass and better feed conversion within one to 14 days of age demonstrating higher growth effi ciency during this period. Higher if there meat-type strain development capability, with better carcass yield at 35 days of age.

O objetivo deste trabalho foi avaliar o desempenho e o rendimento da carcaça e partes (asa, coxa e sobrecoxa, dorso e peito) de machos e fêmeas de uma linhagem de codornas de corte (Coturnix coturnix sp.) e duas linhagens de codornas de postura (Coturnix coturnix japonica) denominadas amarela e vermelha. Foram utilizadas 1.350 aves, de um a 42 dias de idade, distribuídas em delineamento inteiramente ao acaso, com cinco repetições para cada linhagem. As aves foram alimentadas ad libitum com dietas formuladas para atender as suas exigências nutricionais. O desempenho foi avaliado semanalmente e o rendimento da carcaça e partes aos 35 e 42 dias de idade. A linhagem de corte apresentou maior peso vivo, ganho médio de peso, conversão alimentar, biomassa corporal acumulada de um a 14 dias de idade, rendimento de carcaça aos 35 dias e de peito aos 35 e 42 dias de idade. Dentre as codornas de postura, a vermelha obteve melhores resultados para ganho de peso, conversão alimentar e rendimento de asa aos 42 dias de idade. O efeito do sexo foi observado para o rendimento de asa e dorso aos 35 dias de idade e peito aos 42 dias. Foi verificado que as três linhagens de codornas avaliadas apresentaram maior biomassa corporal acumulada e melhor conversão alimentar no período de um a 14 dias de idade demonstrando maior eficiência de crescimento durante este período. Verificou-se maior capacidade de desenvolvimento da linhagem de corte, com melhor rendimento de carcaça aos 35 dias de idade.

O objetivo deste trabalho foi avaliar o efeito de dietas com glicerol no desempenho produtivo de codornas japonesas de corte e na expressão do mRNA de genes mitocondriais da proteína adenina nucleotídeo translocase (ANT) e da proteína desacopladora (UCP), envolvidas no metabolismo energético e na resposta ao estresse oxidativo. As codornas foram alimentadas com dietas contendo 0, 8 e 12% de glicerol, em substituição parcial ao milho. Aos 28 dias de idade, o RNA total foi extraído de amostras do músculo do peito e a síntese do cDNA foi feita por meio de qRT‑PCR com iniciadores específicos para genes da ANT e UCP, obtidos de Gallus gallus. A conversão alimentar e o consumo de ração foram avaliados para as três dietas testadas. A adição de 8% de glicerol não afetou o desempenho dos animais. No entanto, a adição de 12% aumentou o consumo de ração e piorou a conversão alimentar. O ganho de peso não foi afetado pela inclusão de glicerol na dieta. No grupo alimentado com 8% de glicerol, a expressão da UCP aumentou, mas a da ANT não variou, em comparação ao controle. A expressão da UCP foi menor e a da ANT foi maior no grupo alimentado com 12% de glicerol. A inclusão de 8% de glicerol na dieta não afeta o desempenho de codornas de corte, embora aumente a expressão da UCP. A inclusão de 12% de glicerol piora o desempenho e aumenta a expressão da ANT.

The objective of this work was to evaluate the effect of diets containing glycerol on the productive performance of Japanese meat quails and on the mRNA expression of the mitochondrial genes of the adenine nucleotide translocase (ANT) and uncoupling protein (UCP), involved in energy metabolism and oxidative stress response. The quail were fed diets containing 0, 8, and 12% glycerol in partial substitution of corn. At 28 days of age, total RNA was extracted from samples of breast muscle and cDNA synthesis was done with qRT‑PCR using specific primers for ANT and UCP genes, obtained from Gallus gallus. Feed conversion and feed intake were evaluated for the three tested diets. The addition of 8% glycerol did not affect performance. However, the addition of 12% glycerol increased feed intake and worsen feed conversion. Animal weight gain was not affected by glycerol inclusion in the diet. In the group fed with 8% glycerol, UCP expression increased, but that of ANT did not vary in comparison to the control. The expression of UCP was lower and that of ANT was higher in the group fed with 12% glycerol. The inclusion of 8% glycerol in the diet does not affect the performance of meat quails, although it increases the expression of UCP. The inclusion of 12% glycerol decreases performance and increases the expression of ANT.

O objetivo neste trabalho foi estudar o perfil de crescimento e a deposição de nutrientes nos órgãos (coração, fígado, moela, intestino e proventrículo) de frangos de corte das linhagens Ross e Cobb de ambos os sexos. Foram utilizados 1.920 pintos de 1 dia alojados em boxes de galpão experimental em piso. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 × 2, composto de dois sexos (machos e fêmeas) e duas linhagens (Ross e Cobb), com quatro repetições de 120 aves. As aves foram alimentadas com rações formuladas de acordo com suas exigências nutricionais em cada fase de criação. Os pesos dos órgãos e de seus componentes (água, cinzas, proteína e gordura) foram obtidos semanalmente, com os parâmetros estimados pela equação de Gompertz e as taxas de crescimento determinadas por meio das derivadas das equações. Não houve influência da linhagem nas taxas de crescimento e deposição de nutrientes no coração. As aves Ross foram mais precoces no crescimento e na deposição de água e cinzas no fígado, portanto apresenta maior atividade metabólica na digestão e síntese de nutrientes. A linhagem Cobb foi mais precoce no desenvolvimento do intestino e crescimento e na deposição de nutrientes no proventrículo. Os machos são mais precoces que as fêmeas na taxa de crescimento e deposição de proteína, gordura e água na moela.

This work was carried out with the objective of studying the growth profile and the nutrients deposition on organs (heart, liver, gizzard, intestine and proventricle) of male and female broiler chickens from Ross and Cobb lineages. It was used 1,920 chicks at the age of one day placed in experimental shed boxes on the floor. The experimental design was completely randomized in a 2 × 2 factorial model composed of 2 sexes (mates and females) and two strains with 4 repetitions of 120 broilers each. The broilers were fed formulated diets to supply the nutrient requirements according to each breeding phase. After 24 hours of fasting, the broilers were weighed and slaughtered (1 to 56 days) every week. The weight and components of the organs (water, ash, protein and fat) were weekly obtained, with parameters estimated by the equation of Gompertz and the growth rates were determined by the derived of the equations. There was no influence of the strains on the deposition of nutrients on the heart. Ross chicks were more precocious on growth and on the deposition of water and ashes in the liver, therefore it presents a greater metabolic activity in digestion and nutrient synthesis. Cobb strain was more precocious in the development of the intestine and the growth and deposition of nutrients on the proventricle. Males are more precocious than females on the growth rate and on the protein, fat and water deposition in the gizzard.

Conduziu-se este trabalho, com o objetivo de avaliar o perfil de crescimento e de deposição de nutrientes nas penas, nos músculos, nos ossos e na pele de machos e fêmeas de frangos de corte das linhagens Ross e Cobb, no período de 1 a 56 dias de idade. Foram utilizados 1920 pintos, alojados em boxes de um galpão experimental, em piso. O delineamento experimental foi inteiramente casualizado, fatorial (2 x 2), sendo 2 linhagens e 2 sexos, 4 repetições de 120 aves cada. As aves foram alimentadas com ração, formuladas para atender às exigências nutricionais das aves nas diferentes fases de criação. As aves foram abatidas semanalmente, após um jejum de 24 horas e, em seguida, foram depenadas, evisceradas e realizadas a separação dos ossos, da pele e dos músculos, estes foram pesados e armazenados em câmara fria. Após, foram moídos e liofilizados para realizar as análises laboratoriais. Os parâmetros de peso e de deposição de nutrientes obtidos semanalmente foram estimados em função da equação de Gompertz, e as taxas de crescimento por meio das derivadas das equações. Houve interação (P<0,05) entre linhagens e sexo para peso à maturidade (Pm) e idade de máximo crescimento (t*) do peso e proteínas das penas e Pm, b (taxa de maturidade) e t* de peso do músculo. O crescimento das penas foi mais tardio para as aves Cobb, contudo, a ave Ross foi mais tardia na taxa de crescimento de proteína no músculo. Os parâmetros para peso dos ossos e pele, foram semelhantes entre as linhagens estudadas.

The objective of this work was to study the profile of growth and nutrient deposition on muscles, bones and skin of Ross and Cobb male and female broiler chicken from the age of one day to 56 days. We used 1920 chicks raised in experimental boxes. The experimental design was randomized in a factorial model (2 x 2), with 4 replications of 120 birds each. The birds were fed with diets formulated to supply the nutrient requirements according to each breeding phase. The birds were slaughtered weekly, after 24 hours of fasting, then they were completely plucked and feather samples were collected. The birds were eviscerated and after separating the skin and muscles from the bones, they were weighed, identified and stored in a cold chamber. Thereafter, the samples were ground and freeze-dried to be analyzed in laboratory. There was an interaction (P<0.05) between strains and gender for the parameters Pm and t* of the weight of plucked and fasting birds, water and body ashes, weight and feather proteins and Pm and t* for the muscle weight. Cobb strain was more precocious regarding growth and deposition of protein. The Pm of the muscle did not differ between the studied strains, however, Ross strain presented late growth rate of protein in the muscle and was precocious in the fat deposition rate. The parameters of the Gompertz equation were similar between strains for protein and skin weight.

Este trabalho foi realizado para avaliar o crescimento e desempenho de duas linhagens de aves pescoço pelado. Foram utilizadas 400 aves, distribuídas em um delineamento inteiramente casualizado, os tratamentos consistiram de um esquema fatorial 2 x 2 (linhagens x sexo), com cinco repetições de 20 aves cada. Foram utilizadas aves Pescoço Pelado das linhagens Sasso e ISA Label. As aves receberam rações formuladas à base de milho e de farelo de soja para atender às exigências nutricionais. Foi determinado o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA) aos 28, 56 e 84 dias de idade e o rendimento de carcaça e de partes aos 84 dias de idade. Não foi observada interação entre sexo e linhagem (P>0,05) para nenhuma das variáveis de desempenho analisadas. Para CR e GP houve diferenças significativas (P<0,05) entre as linhagens e entre os sexos nos três períodos. As aves da linhagem Sasso apresentaram desempenho superior à ISA Label. Em relação aos parâmetros descritos da equação de Gompertz, as aves da linhagem Sasso apresentaram maior peso à maturidade (Pm) e tempo em que a taxa de crescimento é máxima (t*) e menor taxa de maturidade (b), indicando que as aves da linhagem ISA Label foram mais precoces para atingir a idade de máximo crescimento. As fêmeas demonstraram melhor aptidão para rendimento de peito e os machos para o rendimento de coxa e de sobra-coxa.

A trial was carried out to evaluate the growth and performance of naked neck birds. Four hundred birds were distributed into four treatments in factorial arrangement (2 strains x 2 genders), with five replicates of 20 birds each. The naked neck strains evaluated were Sasso and ISA Label. The birds were fed a diet formulated with corn and soybean meal according to the nutritional requirements. Food intake, body weight gain and food conversion were determined at 28, 56, and 84 days as well as the yield of carcass and cuts at 84 days. No interaction was observed between gender and strain (P>0.05). Food intake and body weight gain were different (P <0.05) between the strains and between the genders. Sasso strain presented higher performance than ISA Label. The parameters estimated for Gompertz equation, the weigh at maturity (Wm) and time that the growth rate is maximum (t*) were higher and maturity rate (b) was lower for Sasso strain than those of Isa Label strain. These results indicated that the Isa Label was more precocious than Sasso strain. The females showed better breast yield while the males showed better thigh and drumstick yield.