Effects of xylanase supplementation on the apparent digestibility and digestible content of energy, amino acids, phosphorus, and calcium in wheat and wheat by-products from dry milling fed to grower pigs1,2

Abstract

Wheat by-products are feedstuffs that vary in nutritional value, partly because of arabinoxylans that limit nutrient digestibility. Millrun is a byproduct from dry milling wheat into flour and contains varying amounts of the bran, middlings, screening, and shorts fractions. The digestible nutrient content of mill-run is not well known. Effects of xylanase supplementation (0 or 4,000 units/kg of diet) on energy, AA, P, and Ca digestibilities were studied in a wheat control diet and 5 diets containing 30% of a by-product (mill-run, middlings, shorts, screening, or bran) in a 2 x 6 factorial arrangement of treatments. The wheat control diet was formulated to contain 3.34 Mcal of DE/kg and 3.0 g of standardized ileal digestible Lys/Mcal of DE. Diets contained 0.4% chromic oxide. Each of 12 ileal-cannulated pigs (32.5 +/- 2.5 kg) was fed 6 or 7 of 12 diets at 3 times the DE requirement for maintenance in successive 10-d periods for 6 or 7 observations per diet. Feces and ileal digesta were each collected for 2 d. Xylanase tended to increase (P < 0.10) ileal energy digestibility by 2.2 percentage units and the DE content by 0.10 Mcal/kg of DM and increased (P < 0.05) ileal DM digestibility by 2.8 percentage units; a diet x xylanase interaction was not observed. Xylanase increased (P < 0.05) total tract energy and DM digestibilities and the DE content. A diet x xylanase interaction was observed; xylanase increased (P < 0.05) total tract energy digestibility of the millrun diet from 72.1 to 78.9%, DE content from 3.19 to 3.51 Mcal/kg of DM, and DM digestibility from 71.5 to 78.6%. Diet affected (P < 0.05) and xylanase improved (P < 0.05) digestibility and digestible contents of some AA in diets and by-products, including Lys, Thr, and Val. Xylanase increased (P < 0.05) Lys digestibility by 13.8, 5.0, 5.2, 6.0, and 14.1 percentage units in millrun, middlings, shorts, screening, and bran, respectively. Diet affected (P < 0.01) total tract P and Ca digestibilities. Xylanase increased (P < 0.05) digestible P and Ca contents. In summary, nutrient digestibility varies among wheat by-products. Millrun contained 2.65 Mcal of DE/kg of DM, which xylanase increased to 3.56 Mcal of DE/kg of DM. Xylanase improved nutrient digestibility and DE content in wheat by-products; and the extent of improvement depended on the by-product. Xylanase supplementation may maximize opportunities to include wheat byproducts in swine diets and ameliorate reductions in nutrient digestibility that may be associated with arabinoxylans.

Valor nutricional e energia metabolizável de subprodutos do trigo utilizados para alimentação de suínos em crescimento

“…Conforme o grau e as etapas da moagem aplicada, decorrentes do modelo de fluxograma empregado no beneficiamento, o farelo de trigo pode variar em composição e tamanho das partículas, o que é influenciado, principalmente, pela quantidade de farinha residual (Blas Beorlegui, 2003 (Nortey et al, 2008), PB, FDN e FDA (Gomes et al, 2007) são afetadas, negativamente, pelo aumento do conteúdo de fibra bruta na dieta de suínos em crescimento.…”

Nutritive value of wheat and wheat by-products in pig nutrition: A review

“…Arabinoxylans are linear polymers consisting of d-xylose joined with ␤ (1-4) linkages and residues of arabinose (Bedford, 1995). As arabinoxylans represent the major NSP fraction in wheat (McCann et al, 2006), the contents of arabinose and xylose follow the total NSP content (Nortey et al, 2008). Most likely, spring wheat has a lower bushel weight than winter wheat due to lower contents of starch, but higher contents of protein and total NSP, including soluble and insoluble NSP (Kim et al, 2003).…”

Meta-análise da digestibilidade ileal de aminoácidos e minerais em suínos alimentados com dietas contendo enzimas

“…As equações obtidas confirmam que a ação da xilanase aumenta a digestibilidade ileal dos aminoácidos essenciais e não essenciais em 2 a 3%. No entanto, os estudos indicam variações quanto aos aminoácidos que apresentam melhor digestibilidade ileal aparente (Yin et al, 2000a;Barrera et al, 2004;Nortey et al, 2008;Woyengo et al, 2008). Um dos mecanismos de ação da xilanase sobre a digestibilidade dos aminoácidos está relacionado à redução da barreira física entre enzimas e substrato (Yin et al, 2000b).…”

“…A base de dados totalizou 21 artigos, publicados em periódicos internacionais entre 1998 e 2009 (moda: 2008), dos quais 12 avaliaram fitase e 9 avaliaram xilanase (Valaja et al, 1998;Kemme et al, 1999;Selle et al, 2000;Yin et al, 2000aYin et al, , 2000bJondreville et al, 2001;Kies et al, 2001;Traylor et al, 2001;Barrera et al, 2004;Cervantes et al, 2004;Liao et al, 2005;Lyberg et al, 2006;Nyachoti et al, 2006;Radcliffe et al, 2006;Lindberg et al, 2007;Nortey et al, 2007Nortey et al, , 2008Pomar et al, 2008;Woyengo et al, 2008Woyengo et al, , 2009 A meta-análise constituiu-se de três análises sequenciais: gráfica, para controlar a qualidade da base e observar a coerência biológica dos dados; de correlação entre as diversas variáveis, para identificar os fatores relacionados na base; e de variância-covariância. Foram utilizados, nos modelos para as análises de variância-covariância, os fatores com coeficientes de correlação mais elevados e as codificações para os efeitos inter ou intraestudos (Lovatto et al, 2007).…”

“…Portanto, além de interferir na disponibilidade de fósforo, o fitato pode quelatar cátions de Ca, Mg, Fe, Zn e Cu e comprometer a digestibilidade dos aminoácidos (Kies et al, 2001). Assim, em suínos, a utilização de PNAs e de P fítico é limitada pela baixa produção de enzimas específicas pelo trato gastrintestinal (Nortey et al, 2007(Nortey et al, , 2008. A xilanase, por sua vez, atua sobre as frações de fibra da dieta, das quais a celulose e a hemicelulose são as principais fontes de substrato para esta enzima .…”