Nilva Kazue Sakomura

Estudo do crescimento, desempenho, rendimento de carcaça e qualidade de carne de três linhagens de frango de corte

This is study aimed to compare growth performance, meat quality, and carcass yield of three broiler chicken strains: Cobb, Paraiso Pedres and ISA Label. The experiment was analyzed according to a randomized design, with five replicates of 29 birds per treatment. Weight gain, feed intake, and feed conversion were evaluated weekly. Adjustments performed according to Gompertz model to describe the birds growth were based on mean weight gain. The birds growth rate was obtained by the Gompertz derivative model. When the males of each strain reached body weight of 2.5 kg, three broilers of replicate were slaughtered for carcass analyses. Samples of breast samples of two birds were taken for physical-chemical characteristics analyses. Cobb birds had higher weight gain and feed intake, followed by Paraiso Pedres and ISA Label. Cobb birds exhibited higher values of growth potential, according to Gompertz equation. Cobb birds showed higher values of carcass yield, breast, drumstick, liver, intestines, and proventricule than the other strains, that did not differ between them. Cobb birds presented higher values of pH and water retention capacity of breast meat. Paraiso Pedres and ISA Label exhibited stronger red color intensity. Sex did not influence meat quality but influenced feet, drumisticks + upper drumstick, and heart, that were higher in males. Females exhibited higher values of breast, abdominal fat, liver, gizzard, and proventricule yield. Therefore, Cobb strain showed greater capacity to reach higher growth rates and meat quality, and Paraiso Pedres and ISA Label birds exhibited colors that satisfy consumers demand.

Comparison of free range broiler chicken strains raised in confined or semi-confined systems

The present study was carried out to compare the growth curve, performance and carcass yield of two broiler strains, Paraiso Pedres (PP) and ISA Label (ISA), raised in confined or semi-confined systems. It was used a completely randomized design with five replicates, consisting of 20 and 29 birds in semi-confined and confined systems, respectively. Semi-confined birds had free access to pasture at 28 days of age. Performance data were recorded weekly by building growth curves as well as calculating the growth rate. After reaching the recommended body weight (2.5 kg), male birds were slaughtered for physicochemical analysis of carcass, parts and organs. Semi-confined PP and ISA birds showed higher growth potential, higher weight gain, lower feed intake and better feed-to-gain ratio than confined birds. No interactions were observed for carcass yield and meat quality characteristics. Males presented higher yields of feet, drumstick, thigh, drumstick + thigh, and heart, while females presented higher breast and abdominal fat yield. Breast meat from ISA Label birds was more yellowish than from PP, whereas less soft meat was observed in semi-confined birds.

Modeling Energy Utilization in Broiler Breeders, Laying Hens and Broilers

The factorial approach has been used to partition the energy requirements into maintenance, growth, and production. The coefficients determined for these purposes can be used to elaborate energy requirement models. These models consider the body weight, weight gain, egg production, and environmental temperature to determine the energy requirements for poultry. Predicting daily energy requirement models can help to establish better and more profitable feeding programs for poultry. Studies were conducted at UNESP-Jaboticabal to determine metabolizable energy (ME) requirement models for broiler breeders, laying hens, and broilers. These models were evaluated in performance trials and provided good adjustments. Therefore, they could be used to establish nutritional programs. This review aims to outline the results found at UNESP studies and to show the application of models in nutritional programs for broiler breeders, laying hens, and broilers.

Growth and body nutrient deposition of two broiler commercial genetic lines

The objective of this work was to study growth and body nutrient deposition profiles of male and female Cobb and Ross broilers using Gompertz equations. A total number of 1,920 one- to 56-day-old broilers were used. A randomized experimental design in a factorial arrangement (2 strains x 2 sex), with 4 replicates of 120 birds each, was applied. Diets were formulated to supply the nutrient requirements recommended by the genetic companies. A sample of birds was weekly weighed and sacrificed after 24 hours fasting. Carcasses were defeathered and weighed again. The parameters of the Gompertz equation for body weight and its components (water, ashes, protein, and fat) were estimated. An interaction (p<0.05) between sex and breed was observed for mature weight (Wm) (kg), growth rate (b) (daily) and time at maximum growth rate (t*) (day) of body weight, and body water and ash. Cobb was presented earlier growth and body protein and ash deposition. Ross strain was superior in body water deposition.

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

The growth curves of egg pullets of semi heavy: Hy Line Brown (HLB) and Hisex Brown (HSB) and light strains: Hy Line W36 (HLW36) and Hisex White (HSW) were evaluated. Three hundred birds of each strain were assigned to a completely randomized design with four replicates of 75 birds. Body weight (BW), feather weight (FW) and body depositions of protein, fat, ash and water were weekly measured. The growth curves were determined by Gompertz function with data collections. The semi heavy birds were later than the light ones for BW, with greater body growth rates and weights at maturity. The HLW36 were 64.23 g lighter at maturity than the HSW. Data obtained for feather growth and protein deposition were similar, but the semi heavy birds showed greater weight at maturity (WM) than the light ones. However, for these components, the birds Hy Line had larger depositions than Hisex. HLW36 strain had smaller feather rate at maturity, making it three days later than HSW. The lowest protein deposition in the end of growth period caused the deviation of energy ingested for fat deposition in HSB birds and overestimated the WM in relation to HLB birds. Hy Line birds had later body ash composition and showed greater WM than Hisex. Among the studied variables, Hy Line birds had always heavier WM, however, the body water content of Hisex birds was greater and the maximum rates at maturity were later. This fact explains the similarity in the weight gain among the studied strains, once other body components were greater for Hy Line birds.

Comparação de métodos de determinação da gravidade específica de ovos de poedeiras comerciais

O objetivo deste trabalho foi avaliar um aparelho desenvolvido para a determinacao da gravidade especifica (GE) do ovo em agua, comparando-o ao metodo de imersao em solucao salina. Foram coletados 200 ovos de duas linhagens de poedeiras comerciais, divididos ao acaso em dois grupos de 50 ovos por linhagem e submetidos a duas sequencias de determinacao da GE. Nao foram observadas diferencas significativas entre os metodos utilizados. A determinacao da GE dos ovos utilizando o aparelho desenvolvido pode ser realizada com a mesma precisao da determinacao em solucao salina.

Efeito da Idade dos Frangos de Corte sobre a Atividade Enzimática e Digestibilidade dos Nutrientes do Farelo de Soja e da Soja Integral

This work aimed to investigate the effect of broilers age in the digestibility of nutrients in extruded and toasted full fat soybean (EFFS and TFFS) and soybean meal plus oil (SMO), and in the production of digestive pancreatic enzymes. Five digestibility assays were carried out with broilers of one, two, three, four , and six weeks of age. Total collected excreta methodology was applied. The activities of amylase and pancreatic trypsin enzymes increased linearly with the broilers age, as well as the allometric growth of the pancreas. The highest allometric growth ratio occurred in the second week, coincidentally with the period of increasing activity of the digestive enzymes. However, for lipase activity, distinct age affect was found for each feeds. For birds fed on TFFS, the enzyme activity increased linearly with age, while those fed on EFFS, SMO, and concentrate a quadratic effect was observed. The digestibility coefficients for dry matter and ether extract and the soybeans metabolizable energy (ME) varied at different proportions by age. A positive correlation between ether extract digestibility and lipase activity was also observed. The results of corrected apparent and actual metabolizable energy for EFFS presented a quadratic profile in function of age, increasing ME up to the third week and decreasing after this period. However, ME of TFFS, SMO and concentrate was not affected by chicks age. The nutrient digestibility of feedstuffs varies with chicks age, due to the different enzymatic activities.

Efeito do nível de energia metabolizável da dieta no desempenho e metabolismo energético de frangos de corte

Objetivou-se, nesta pesquisa, estudar o efeito dos niveis de energia metabolizavel (EM) da dieta sobre o desempenho e o metabolismo energetico de frangos de corte machos na fase de crescimento (22 a 43 dias de idade) em condicoes de temperatura ambiente. Foram utilizadas 288 aves distribuidas aleatoriamente por tres niveis de energia da dieta (3.050, 3.200 e 3.350 kcal/kg) e tres niveis de alimentacao (ad libitum, 75 e 50% do ad libitum), com quatro repeticoes de oito aves, para determinacao das exigencias de mantenca e das eficiencias energeticas. Foi utilizado o metodo do abate comparativo, sendo que 12 aves foram abatidas no inicio do ensaio experimental, para determinacao da composicao corporal inicial, e 144 aves foram usadas para determinacao da energia metabolizavel das dietas experimentais. Os niveis de energia influenciaram na ingestao de energia metabolizavel (IEM) e, consequentemente, a retencao de energia na carcaca (ER) e a producao de calor (PC). As exigencias de energia metabolizavel de mantenca (EMm) determinadas foram 131,12; 140,96 e 131,78 kcal/kg0,75/dia para os niveis de energia alto, medio e baixo, respectivamente. O nivel de energia mais alto (3.350 kcal/kg) na dieta dos frangos de corte proporcionou melhores resultados de desempenho, enquanto o medio (3.200 kcal/kg), melhor equilibrio na eficiencia de utilizacao de energia para deposicao de proteina e gordura, consequentemente, melhor qualidade da carcaca, em decorrencia da menor deposicao de gordura.

Níveis protéicos na ração de frangos de corte na fase de crescimento

O objetivo deste trabalho foi determinar o nivel minimo de proteina bruta para atender as exigencias nutricionais de frangos de corte Hubbard, machos e femeas, na fase de crescimento. Oitocentos e oitenta pintos machos e femeas de 22 a 42 dias de idade foram distribuidos ao acaso em esquema fatorial 5x2 (niveis de proteina bruta x sexos), com quatro repeticoes de 22 aves. Os niveis de proteina testados foram 15%, 17%, 19%, 21% e 23%. Houve efeito quadratico dos niveis de proteina no ganho de peso e na conversao alimentar dos machos. Em relacao as femeas, o efeito foi quadratico no ganho de peso e linear na conversao. A relacao entre o rendimento de carcaca e o nivel de proteina bruta da racao foi linear e independente do sexo. O consumo de racao, a gordura abdominal e o rendimento de peito foram influenciados apenas pelo sexo. Recomenda-se 21,70% de proteina bruta para os machos e 19,00% para as femeas, na fase de crescimento.

Efeito de diferentes níveis de sódio e fósforo sobre o desempenho e a qualidade da casca dos ovos de poedeiras comerciais

The objective of this experiment was to evaluate the different levels of manganese and phosphorus (P) on the performance and eggshell quality and on determined blood constituents of 96 laying hens Hy-Line W36, with 60 weeks of age, distributed in 24 lots with four hens each. A completely randomized experimental design was used in a factorial arrangement (3 x 2), manganese levels (70, 140 and 210 ppm) and total phosphorus levels (.35 and .55%), totalizing six treatments with four replicates each. The experimental diets were isoproteic (16.0% CP), isocaloric (2800 kcal ME/kg), isocalcium (4.0% Ca) and isosodium (.16% Na). The manganese levels did not alter the production and eggshell quality. However, when hens were fed diets containing .35% of total P, there were observed decreases in the egg production, egg weight and egg mass, without alterations in eggshell quality characteristics. The supplemental manganese levels were not effective to improve eggshell quality at the final phase of production. The total phosphorus level of .35% was inadequate for the laying hens to express the normal production characteristics