English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

One thousand eight hundred and ninety male broilers of two strain crosses (fast and slow initial growth) were fed different ideal protein profiles in four-phase feed programs: 1 to 7, 8 to 21, 22 to 34 and 35 to 40 days of age. All vegetable, corn-soybean meal feeds were formulated to maintain the Met+Cys:Lys and Thr:Lys relationships at 75 and 65%, respectively, on true digestible basis. Three ideal protein profiles were used: low, medium and high. From 1 to 21 days of age, half of the birds fed low and high diets were changed to high and low diets, respectively. Birds on the medium diet were kept on the same diet until the end of the study. A 3 × 2 (ideal protein profile x strain cross) factorial design was used for the period from 1 to 21 days and a 5 × 2 design thereafter. Carcass and commercial cuts were performed at 34 and 40 days of age to determine corresponding live weight and carcass yields. In general, the fast strain growth was superior in comparison to the low one when live performance and carcass and commercial cuts were evaluated. Live performance was positively affected by the increases in the dietary protein profiles; however, processing yield parameters could not be related with the dietary parameters. The low diets, which have similar protein contents to those used in some integrations, were shown to produce poor responses and, therefore are not recommended for broilers from 1 to 40 days of age. Alternating low and high ideal protein profiles at 21 days could result in similar feed conversions, and therefore, can lead to production cost reduction. Mil oitocentos e noventa frangos de corte machos de duas linhagens comerciais (de crescimento inicial rápido e lento) receberam dietas com diferentes perfis de proteína ideal em programas alimentares de quatro fases: 1 a 7; 8 a 21; 22 a 34; e 35 a 40 dias de idade. Dietas exclusivamente vegetais, à base de milho e farelo de soja, foram formuladas de modo a manter as relações Met+Cis:Lis e Ter:Lis em 75 e 65%, respectivamente, em base digestível verdadeira. Foram utilizados três perfis de proteína ideal: baixo, médio e alto. Aos 21 dias de idade, metade das aves consumindo dieta de perfil baixo passou a receber perfil alto e metade daquelas que receberam perfil alto passaram a receber dieta de perfil baixo. As aves que recebiam dieta de perfil médio permaneceram sem alteração até o final do estudo. Utilizou-se esquema fatorial 3 × 2 (perfil de proteína ideal × linhagem) para o período de 1 a 21 dias e 5 × 2 para o período de 21 a 40 dias de idade. Além das respostas de desempenho zootécnico, foram realizados abates aos 34 e 40 dias de idade para determinação dos rendimentos de carcaça e de cortes. De modo geral, a linhagem de crescimento rápido foi superior à de crescimento lento para as respostas de crescimento e rendimentos de carcaça e cortes. As aves responderam significativamente ao aumento no conteúdo proteico das rações, independentemente da linhagem utilizada para características de desempenho zootécnico; entretanto, as respostas de rendimento pós-abate não puderam ser relacionadas da mesma forma. A alternância de perfis proteicos aos 21 dias pode levar a conversões alimentares similares e, portanto, reduzir o custo de produção

Responses of fast and slow growth broilers fed all vegetable diets with variable ideal protein profiles