Fibra para cães: efeitos sobre o processo de extrusão, digestibilidade, fermentação microbiana, tempo de retenção intestinal e palatabilidade de rações para cães
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Data
2015-12-17
Autores
Monti, Mariana [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Existe um grande interesse atual no desenvolvimento de alimentos para cães com alta concentração de nutrientes e baixa densidade energética. A adição de fibra em rações para pet é uma maneira de controlar as calorias do alimento propiciando benefícios, e ao mesmo tempo, promover a utilização mais eficiente das fontes de fibra que não são destinadas à alimentação humana. Desta forma, foram formuladas 8 dietas experimentais: Controle (CO), sem adição de ingredientes fibrosos; dietas com fibra de goiaba (GF3, GF6, GF12), com níveis de inclusão de 3%, 6%, e 12%; dietas com fibra de cana (SC), com 9% de inclusão e dois diferentes tamanho de partícula (grande - SCL e pequeno- SCS) e dietas com farelo de trigo (WB), com 32% de inclusão e dois diferentes tamanhos de partícula (grande- WBL e pequeno- WBS). Objetivou-se neste trabalho avaliar os efeitos de inclusões crescentes de fibra de goiaba, bem como o efeito da fibra de cana e do farelo de trigo moídos em diferentes tamanhos sobre o processo de extrusão, digestibilidade dos nutrientes, fermentação no intestino, tempo de retenção gastrointestinal (TRGI) e palatabilidade das dietas. Foi utilizado o programa SAS para análise estatística e as médias foram comparadas por contrastes polinomiais e ortogonais (P<0,05). No Capítulo 2, a adição da fibra de goiaba resultou em aumento linear da amperagem (P<0,001), temperatura (P<0,001) e pressão (P<0,001) na saída da extrusora. Níveis crescentes de goiaba trouxeram maior implemnto de energia mecânica específica (EME) (P<0,001), redução na expansão radial (ER) (P<0,001), aumento na densidade aparente (DA) e menor cozimento do amido. A fibra de cana, em comparação com a fibra de trigo reduziu a amperagem (P<0,001), EME (P=0,013) e DA, mas aumentou o comprimento específico (P<0,001). A inclusão de fibra em menor tamanho reduziu a amperagem (P<0,001), EME (P<0,001) e DA, mas aumentou a ER (P=0,008). No capítulo 3, as rações CO, GF3, GF6 e GF12 foram fornecidas a 24 Beagles adultos por 15 dias de adaptação e após esse período os animais foram alojados em gaiolas metabólicas para acessar a digestibilidade e fermentação. Os animais receberam por via oral uma pílula contendo 10 marcadores radiopacos para determinação do TRGI. O teste de palatabilidade foi realizado com 38 cães utilizando-se teste versus por comparação. A adição da fibra de goiaba não alterou a ingestão de nutrientes, exceto para fibra dietética total (FDT) (P<0,001). A inclusão de fibra resultou em menor digestibilidade para matéria seca (MS) (P<0,001), matéria orgânica (MO) (P<0,001), proteína (PB) (P<0,001), energia bruta (EB) (P<0,001) e energia metabolizável do alimento (EM) (P<0,001). A fibra de goiaba não alterou a concentração fecal de amônia, ácido láctico, pH fecal e ácidos graxos de cadeia ramificada (AGCR), porém, reduziu a concentração dos ácidos graxos de cadeia curta (AGCC) acético e propiônico (P=0,007 e P=0,006). A inclusão de 6% de goiaba não alterou o TRGI, mas 12% de inclusão resultou em menor TRGI (P=0,046) comparado com a dieta CO. No capítulo 4, as dietas CO, SCL, SCS, WBL e WBS foram fornecidas a 30 Beagles adultos seguindo as mesmas metodologias do estudo com fibra de goiaba. Em comparação com a dieta CO, as dietas com fibra de cana e trigo aumentaram a ingestão de todos os nutrientes (P<0,001) e diminuíram a digestibilidade da MS, MO e ME (P<0,001), sem diferenças para PB, gordura, FDT e amido. Cães alimentados com farelo de trigo, em relação aos alimentados com fibra de cana, obtiveram aumento na concentração de ácido láctico (P<0,001) e diminuição da amônia (P<0,001) e pH (P<0,001) fecal, ácido isovalérico e ACCR total (P<0,001). A inclusão de ambas as fontes de fibra reduziram o TRGI comparado com a dieta CO (P<0,001). Os cães apresentaram preferência alimentar pela dieta sem fibra (P<0,01) sem efeitos claros quanto ao tamanho de partícula. No geral, concluiu-se que a adição de fibras limita o cozimento do amido e aumenta o gasto de energia na extrusão; torna as dietas duras, densas e exigem mais cautela para serem recobertas. A fibra de goiaba, por sua vez não causa alterações na fermentação intestinal e no TRGI de cães até 12% de inclusão. A fibra de cana e trigo com pequenos tamanhos de partículas utilizado nesse estudo não resultaram em melhoras quanto à digestibilidade de dietas com alta fibra e não alteraram o TRGI; entretanto, interferiram na formação de AGCC e preferência alimentar dos animais.
There is a great interest in developing dog food with high nutrient concentration and low energy density. The addition of fibers to commercial pet food is one way to moderate the energy density of these foods, provide health benefits to dogs and cats and, at the same time, to promote a more efficient utilization of feed resources that are not used in human foods. For this, a total of 8 fiber diets were manufactured: Control (CO), with no fibrous ingredient addition; guava fiber diets (GF3, GF6, GF12), at the inclusion levels of 3%, 6%, and 12%; sugarcane fiber diets (SC), with 9% inclusion and two different particle size (large - SCL and small - SCS) and wheat bran fiber diets (WB), with 32% inclusion and two different particle size (large - WBL and small - WBS). This study aimed to evaluate the effect of growing inclusion of guava fiber, as the effect of sugarcane and wheat bran with different particle size on extrusion processing, nutrients digestibility, intestinal fermentation, gastrointestinal retention time (GIRT) and palatability. The software SAS was utilized to statistical analysis and the meanings were compared by polynomial and orthogonal contrasts (P<0.05). In chapter 2, guava fiber inclusion resulted in linear increase of the amperage (P<0.001), temperature (P<0.001) and pressure (P<0.001) at the extruder die was verified. A higher implementation of specific mechanical energy (SME) (P<0.001), a reduction in radial expansion (P<0.001), and a greater specific piece density was verified for guava fiber supplemented diets. The sugarcane fiber in comparison with wheat bran reduced amperage (P<0.001), SME (P=0.013) and piece density, but increased specific length (P<0.001). The inclusion of fibers with smaller size, reduced the engine amperage (P<0.001), SME (P<0.001) and extruded piece density, but increased the radial expansion (P=0.008). In chapter 3, the diets CO, GF3, GF6 and GF12 were fed to 24 adult Beagle dogs during 15 days of adaptation and afterwards the dogs were housed in cages for fecal collection to assess digestibility and fermentation end products. The dogs received an oral pill containing radiopaque markers to determine gastrointestinal retention time (GIRT). Diet palatability was evaluated by the two-pan test using 38 dogs. The addition of guava fiber did not change nutrient intake except for dietary fiber (P<0.001). Fiber inclusion resulted in lower total tract apparent digestibility for dry matter (P<0.001), organic matter (P<0.001), crude protein (P<0.001), crude energy (P<0.001) and food ME (P<0.001). Guava fiber addition did not change the fecal concentration of ammonia, lactic acid, fecal pH, and branched chain fatty acids but it decreased short chain fatty acid concentrations for acetic and propionic acids (P=0.007 and P=0.006). The inclusion of 6% guava fiber did not alter the gastrointestinal transit time, but 12% inclusion did result in a reduced GIRT (P=0.046) compared to the control diet. The chapter 4, the Diets CO, SCL, SCS, WBL e WBS were offered to 30 adult Beagles following the same methodologies used in guava fiber study. In comparison with the CO diet, the diets with sugarcarne and wheat bran fiber increased the nutrient intake (P<0.001) and decreased the coefficients of total tract apparent digestibility (CTTAD) of DM, OM and food ME (P<0.001) without differences for CP, fat, TDF and starch. Dogs fed WB diets, comparing fiber sources, had greater lactic acid concentration (P<0.001) and lower fecal pH and fecal ammonia (P<0.001), isovaleric and total branched chain fatty acids concentration (P<0.001). The inclusion of both fibers decreased the gastrointestinal retention time compared to CO diet (P<0.001). Palatability testing results indicated that the CO treatment was preferred over the fiber diets without clear effects about particle size. In general, fibers addition limited the starch cooking, increases processing cost, turn the kibbles hard, and could bring difficulties for coating. The guava fiber not occasioned alterations in the intestinal fermentation and in the GIRT until 12% inclusion. The sugarcane and wheat bran with small particles did not result in improved digestibility of a high fiber diet and GIRT; however, may have interfered on BCFA and palatability.
There is a great interest in developing dog food with high nutrient concentration and low energy density. The addition of fibers to commercial pet food is one way to moderate the energy density of these foods, provide health benefits to dogs and cats and, at the same time, to promote a more efficient utilization of feed resources that are not used in human foods. For this, a total of 8 fiber diets were manufactured: Control (CO), with no fibrous ingredient addition; guava fiber diets (GF3, GF6, GF12), at the inclusion levels of 3%, 6%, and 12%; sugarcane fiber diets (SC), with 9% inclusion and two different particle size (large - SCL and small - SCS) and wheat bran fiber diets (WB), with 32% inclusion and two different particle size (large - WBL and small - WBS). This study aimed to evaluate the effect of growing inclusion of guava fiber, as the effect of sugarcane and wheat bran with different particle size on extrusion processing, nutrients digestibility, intestinal fermentation, gastrointestinal retention time (GIRT) and palatability. The software SAS was utilized to statistical analysis and the meanings were compared by polynomial and orthogonal contrasts (P<0.05). In chapter 2, guava fiber inclusion resulted in linear increase of the amperage (P<0.001), temperature (P<0.001) and pressure (P<0.001) at the extruder die was verified. A higher implementation of specific mechanical energy (SME) (P<0.001), a reduction in radial expansion (P<0.001), and a greater specific piece density was verified for guava fiber supplemented diets. The sugarcane fiber in comparison with wheat bran reduced amperage (P<0.001), SME (P=0.013) and piece density, but increased specific length (P<0.001). The inclusion of fibers with smaller size, reduced the engine amperage (P<0.001), SME (P<0.001) and extruded piece density, but increased the radial expansion (P=0.008). In chapter 3, the diets CO, GF3, GF6 and GF12 were fed to 24 adult Beagle dogs during 15 days of adaptation and afterwards the dogs were housed in cages for fecal collection to assess digestibility and fermentation end products. The dogs received an oral pill containing radiopaque markers to determine gastrointestinal retention time (GIRT). Diet palatability was evaluated by the two-pan test using 38 dogs. The addition of guava fiber did not change nutrient intake except for dietary fiber (P<0.001). Fiber inclusion resulted in lower total tract apparent digestibility for dry matter (P<0.001), organic matter (P<0.001), crude protein (P<0.001), crude energy (P<0.001) and food ME (P<0.001). Guava fiber addition did not change the fecal concentration of ammonia, lactic acid, fecal pH, and branched chain fatty acids but it decreased short chain fatty acid concentrations for acetic and propionic acids (P=0.007 and P=0.006). The inclusion of 6% guava fiber did not alter the gastrointestinal transit time, but 12% inclusion did result in a reduced GIRT (P=0.046) compared to the control diet. The chapter 4, the Diets CO, SCL, SCS, WBL e WBS were offered to 30 adult Beagles following the same methodologies used in guava fiber study. In comparison with the CO diet, the diets with sugarcarne and wheat bran fiber increased the nutrient intake (P<0.001) and decreased the coefficients of total tract apparent digestibility (CTTAD) of DM, OM and food ME (P<0.001) without differences for CP, fat, TDF and starch. Dogs fed WB diets, comparing fiber sources, had greater lactic acid concentration (P<0.001) and lower fecal pH and fecal ammonia (P<0.001), isovaleric and total branched chain fatty acids concentration (P<0.001). The inclusion of both fibers decreased the gastrointestinal retention time compared to CO diet (P<0.001). Palatability testing results indicated that the CO treatment was preferred over the fiber diets without clear effects about particle size. In general, fibers addition limited the starch cooking, increases processing cost, turn the kibbles hard, and could bring difficulties for coating. The guava fiber not occasioned alterations in the intestinal fermentation and in the GIRT until 12% inclusion. The sugarcane and wheat bran with small particles did not result in improved digestibility of a high fiber diet and GIRT; however, may have interfered on BCFA and palatability.
Descrição
Palavras-chave
Fibras, Nutrição de cães, Preferência alimentar, Resposta fermentativa, Tamanho de partícula, Tempo de retenção intestinal, Fiber, Fermentative response, Food preference, Gastrointestinal retention time, Particle size