• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeito de diferentes estratégias nutricionais e da genética sobre a incidência de miopatias peitorais de frangos de corte / Effect of different nutritional strategies and genetics on the incidence of pectoral myopathies in broiler chickens

Fonseca, André Camêlo 12 April 2019 (has links)
A importância econômica da carne de aves conduziu extensivos esforços de seleção genética para aumentar o rendimento de peito de frangos de corte comerciais proporcionando músculos formados com o dobro de fibras musculares e com maior diâmetro. Esse aumento causou a incidências de alterações musculares peitorais denominadas de White Striping e Wooden Breast, conhecida respectivamente como estrias brancas e peito madeira. Foram utilizados 1.755 pintos de 3 linhagens (Cobb, Ross e Hubbard) distribuídos em delineamento inteiramente casualizado em arranjo fatorial 3X5 (três linhagens, cinco estratégias nutricionais) com nove repetições por tratamento, distribuídas em 135 boxes e densidade de 13 aves/m². Foram abatidas 1 ave por repetição aos 35, 42, 49 e 56 dias para as análises de desempenho, rendimento de carcaça e cortes, miopatias peitorais e composição nutricional do peito. As estratégias nutricionais (EN) foram: EN1 - desempenho regular, 500 FTU de fitase; EN2 - desempenho superior, 500 FTU de fitase; EN3 - desempenho superior, 1500 FTU; EN4 - desempenho superior, 500 FTU, complexo antioxidante; EN5 - desempenho superior, 1500 FTU, complexo antioxidante. Entre as linhagens, Ross predominou com o maior consumo de ração com 21, 49 e 56 dias e maior peso médio em todas as idades. A linhagem Hubbard que prevaleceu com a menor conversão alimentar aos 49 e 56 dias de idade. Para rendimento de carcaça Cobb e Ross foram superiores ao Hubbard com 35 dias e predominaram maior rendimento de peito entre as idades de abate. Hubbard obteve maior rendimento de pernas em todas as idades. Para consumo de ração, peso médio e conversão alimentar por EN, o consumo de ração só apresentou diferença significativa entre as EN nas fases iniciais (8-21 dias) e finais (50-56 dias). Quando observado o peso médio, a EN 5 teve o maior peso em todas as idades. O menor peso foi para as aves da EN 1 em todas as idades. Na análise de conversão percebe-se que a EN 1 teve a maior conversão nas fases: inicial (8-21 dias), crescimento (22-49 dias) e final (50-56 dias). EN 5 obteve a menor conversão alimentar na fase inicial e final. Não houve diferença significativa para incidência de White Striping em todas as idades entre linhagens. Para Wooden Breast (WB), houve diferença significativa entre as linhagens com 42, 49 e 56 dias de idade, onde Cobb prevaleceu com maior incidência nessas idades. Ross obteve junto ao Cobb as maiores incidências com 49 e 56 dias. Não houve diferença significativa entre White Striping e Wooden Breast entre as estratégias nutricionais. Para composição química do peito das aves entre as linhagens, observa-se que só houve diferença significativa para extra etéreo (EE) com 49 dias de idade, onde Cobb e Ross tiveram o maior percentual. Entre as estratégias nutricionais não houve diferença significativa para composição nutricional do peito. Há diferença significativa entre Cobb, Ross e Hubbard para desempenho e rendimento, o que afetam a incidência das miopatias peitorais. No entanto, entre as estratégias nutricionais não observou diferença significativa para incidências de White Striping e Wooden Breast. / The economic importance of poultry meat led extensive genetic selection efforts to increase breastfeeding of commercial broilers by providing muscles formed with twice the muscle fibers and with larger diameter. This increase caused incidences of pectoral muscle changes called White Striping and Wooden Breast, known respectively as white striations and chest wood. A total of 1,755 chicks (Cobb, Ross and Hubbard) were distributed in a completely randomized design in a 3X5 factorial arrangement (three lines, five nutritional strategies) with nine replicates per treatment, distributed in 135 boxes and density of 13 birds / m². One bird per replicate was slaughtered at 35, 42, 49 and 56 days for analyzes of performance, carcass yield and cuts, pectoral myopathies and nutritional composition of the breast. The nutritional strategies (EN) were: EN1 - regular performance, 500 FTU of phytase; EN2 - superior performance, 500 FTU of phytase; EN3 - superior performance, 1500 FTU; EN4 - superior performance, 500 FTU, antioxidant complex; EN5 - superior performance, 1500 FTU, antioxidant complex. Among the lineages, Ross predominated with the highest feed intake at 21, 49 and 56 days and highest mean weight at all ages. The Hubbard strain prevailed with the lowest feed conversion at 49 and 56 days of age. For carcass yield Cobb and Ross were superior to Hubbard with 35 days and had a higher breast yield between the slaughter ages. Hubbard obtained higher leg yield at all ages. For feed intake, mean weight and feed conversion by EN, feed intake only showed a significant difference between the early (8-21 days) and the late (50-56 days). When the average weight was observed, EN 5 had the highest weight in all ages. The lowest weight was for birds of EN 1 at all ages. In the conversion analysis, it was observed that EN 1 had the highest conversion in the phases: initial (8-21 days), growth (22-49 days) and final (50-56 days). EN 5 obtained the lowest feed conversion in the initial and final phases. There was no significant difference in the incidence of White Striping at all ages between strains. For Wooden Breast (WB), there was a significant difference between the 42, 49 and 56 days old strains, where Cobb prevailed with higher incidence at these ages. Ross obtained the highest incidences with Cobb at 49 and 56 days. There was no significant difference between White Striping and Wooden Breast between nutritional strategies. It was observed that there was only a significant difference for fat at 49 days of age, where Cobb and Ross had the highest percentage. Among nutritional strategies there was no significant difference in the nutritional composition of the breast. There is a significant difference between Cobb, Ross and Hubbard for performance and yield, which affect the incidence of pectoral myopathies. However, among the nutritional strategies did not observe significant difference for incidences of White Striping and Wooden Breast.

Page generated in 0.0442 seconds