Avaliação da matriz nutricional da enzima fitase em rações contendo sorgo para poedeiras comerciais

Abstract

RESUMO -Avaliaram-se os efeitos da inclusão de fitase e de sua matriz nutricional em rações contendo sorgo sobre o desempenho das aves, a qualidade dos ovos, a ingestão e a excreção e retenção de fósforo e nitrogênio em poedeiras comerciais.Utilizaram-se 180 poedeiras comerciais, distribuídas em delineamento inteiramente ao acaso em esquema fatorial 2 × 2 + 1, com dois níveis de fitase (0 e 500 FTU/kg de ração) e dois níveis de substituição do milho pelo sorgo (50 e 100%) e uma ração testemunha (isenta de sorgo e fitase), constituindo cinco tratamentos com seis repetições de seis aves. As rações foram à base de milho e farelo de soja, sem fitase e sorgo, considerando a matriz nutricional da fitase. O desempenho e a qualidade dos ovos foram avaliados em quatro períodos de 28 dias. Ao final do experimento, um ensaio de metabolismo foi realizado para quantificar a ingestão, excreção e retenção aparente de fósforo e nitrogênio e avaliar a viabilidade econômica das rações. Ao considerar a matriz nutricional da fitase, as exigências em energia, cálcio, fósforo, proteína e aminoácidos foram atendidas, mesmo com a redução dos níveis nutricionais da dieta, e o desempenho e a qualidade dos ovos não foram comprometidos. A adição de fitase nas rações possibilitou reduzir todos os parâmetros econômicos avaliados. O sorgo pode substituir totalmente o milho e ser o único grão energético da dieta.Palavras-chave: alimentos alternativos, avaliação econômica, aves, retenção aparente de fósforo e nitrogênio Evaluation of the nutritional matrix values for phytase enzyme in laying hens diets with sorghum ABSTRACT -The effects were assessed of including phytase and its nutritional matrix in diets containing sorghum on the performance of the birds, egg quality, intake and phosphorus excretion and retention in laying hens. One hundred and eighty laying hens were arranged in a randomized complete design in a 2 × 2 + 1 factorial arrangement with two phytase levels (0 and 500 FTU/kg diet), two levels of corn replacement for sorghum (50 and 100%) and a control diet (without phytase and sorghum) forming five treatments and six replications of six birds. The diets were based on corn and soybean meal, without phytase and sorghum, considering the phytase nutritional matrix. Performance and egg quality were determined in four 28-day periods. At the end of the experiment, a metabolism trial was carried out to quantify intake, excretion and apparent retention of phosphorus and nitrogen and to assess the economic viability of the diets. When the phytase nutritional matrix was considered, the energy, calcium phosphorus, protein and amino acid requirements were met, even with a reduction in the nutritional levels of the diet, and performance and egg quality were not affected. Adding phytase to the diets decreased all the economic parameters. Sorghum can be used to totally replace corn, and can be the only energy grain in the diet.Key Words: alternative foods, apparent phosphorus and nitrogen retention, birds, economic assessment IntroduçãoAtualmente ...

Complete replacement of corn by white or red sorghum in japanese quail feeds

“…The results of the present study are consistent with the findings with laying chickens (Costa et al, 2006;Moreno et al, 2007;Assuena et al, 2008;Ligeiro et al, 2009), indicating that sorghum may completely replace corn in the feed with no detrimental effects on performance. However, yolk pigmentation is impaired.…”

“…Among alternative feedstuffs, sorghum presents adequate nutritional characteristics and it is often used to replace corn, particularly in semi-arid and tropical regions, where sorghum crops present better nutritional yield per area and its price is lower compared with corn (Ligeiro et al, 2009). In terms of nutritional composition, sorghum contains 5% lower metabolizable energy lower digestibility than corn, but its crude protein content is higher (NRC, 1994).…”

“…Tannins can form carbohydrate and protein complexes, thereby reducing diet their digestibility and palatability (Rostagno et al, 2005). However, the development of low-tannin sorghum varieties has allowed their increasing inclusion in non-ruminant diets (Moreno et al, 2007), including in layer feeds (Costa et al, 2006;Moreno et al, 2007;Assuena et al, 2008;Ligeiro et al, 2009). To date, the low level of carotenoid pigments in sorghum has been the main limitation for its inclusion in layer diets.…”

“…To date, the low level of carotenoid pigments in sorghum has been the main limitation for its inclusion in layer diets. When sorghum replaces corn, there is a proportional reduction in the intensity of yellow of the yolks, demanding the dietary inclusion of pigments (Costa et al, 2006;Moreno et al, 2007;Assuena et al, 2008;Ligeiro et al, 2009). Faquinello et al (2004) evaluated the replacement of corn by graded Complete Replacement of Corn by White or Red Sorghum in Japanese Quail Feeds levels of high-tannin sorghum in Japanese quail diets and concluded that up to 80% corn can be replaced by sorghum, despite the observed worse feed conversion ratio, egg production and paler egg yolks as dietary sorghum levels increased.…”

Níveis de fósforo e fitase para poedeiras comerciais leves

“…CASARTELLI et al (2005) não detectaram alterações significativas de níveis de fós-foro das dietas, sobre a gravidade específica dos ovos de poedeiras em pós pico de postura. LIGEIRO et al (2009), avaliando a inclusão de fitase em dietas contendo farelo de girassol para poedeiras, não encontrou diferença significativa para gravidade especifica do ovo.…”