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Made available in DSpace on 2022-04-29T08:36:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Citrus pulp pellets (CPP) and orange fiber (OF) are coproducts of the citrus juice industry. OF is a novel fiber source that contains elevated amounts of soluble fiber and has not yet been studied in dog nutrition. The objectives of this study were to evaluate the inclusion of CPP and OF in dog foods and their effects on the extrusion parameters, the coefficient of total tract apparent digestibility (CTTAD) of nutrients, fermentation end products, and palatability. A control diet (CO) without an added fiber source tested was formulated, and the experimental diets were composed of 30 g/kg, 60 g/kg and 120 g/kg CPP or 60 g/kg OF inclusion (as-fed basis). Extrusion parameters were recorded to determine extruder energy balance and kibble macrostructure. Thirty beagle dogs (3.2 ± 0.7 years; 12.4 ± 1.5 kg body weight) were distributed in a randomized block design with 6 dogs per group to evaluate the CTTAD of nutrients and the fermentation products in feces. The results were analyzed by analysis of variance, and means were compared by polynomial and orthogonal contrasts. The inclusion of CPP and OF reduced motor amperage (P < 0.001), mass pressure (P = 0.002), and specific mechanical energy transference (P < 0.001). Kibble macrostructure was affected by a decrease in expansion and an increase in hardness by CPP and OF inclusions (P < 0.001). Starch gelatinization was reduced by CPP (P < 0.001) but not by OF inclusion (P > 0.05). Total dietary fiber (TDF) intake increased (P < 0.001) with the addition of CPP, with a linear reduction in CTTAD of nutrients and energy (P < 0.05). The OF treatment, however, presented similar CTTAD values of DM and CP to those of the CO diet (P > 0.05). The TDF CTTAD was higher for 60 g/kg OF than for 60 g/kg CPP (P = 0.028). The fecal pH decreased, and total short-chain fatty acids (SCFA), acetic acid, butyric acid, and lactate concentrations increased with CPP and OF inclusion (P < 0.05). However, the diet supplemented with OF induced the production of feces with a lower pH and higher total SCFA concentrations than those of feces produced from CPP inclusion (P < 0.001). The OF diet presented a higher preference (65%) than the CO diet (35%) by dogs (P < 0.05). The CPP and OF were fermentable fiber sources, increasing SCFA and butyric acid concentrations in feces. The OF was more fermentable than CPP, with a limited impact on kibble formation, starch cooking, and CTTAD of nutrients and showing good acceptance on diets by dogs. Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias Departamento de Clínica e Cirurgia Veterinária Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias Departamento de Clínica e Cirurgia Veterinária CNPq: 142191/2016-7

Made available in DSpace on 2019-10-06T16:52:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-12-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Water addition is required for proper extrusion, improving dough flow, starch hydration and swelling, viscosity generation, and extrudate cellular formation. The implications of changing in-barrel moisture, however, is little studied for cat foods. Using a nutritionally balanced cat food recipe, the present study evaluated the application of six amounts of water at the extruder barrel, obtaining the following mass in-barrel moistures: 220 g/kg, 270 g/kg, 300 g/kg, 320 g/kg, 350 g/kg, and 370 g/kg. Treatments were processed in a single screw extruder; after stabilization (45 min), extrusion parameters was recorded at each 15 min, with four samplings per moisture level (considered the experimental unit). Treatments were evaluated in a sequential addition of moisture, and results submitted to variance analysis and compared by polynomial contrasts (P < 0.05). The specific mechanical energy application, temperature and pressure of extrusion, starch gelatinization, and in vitro digestibility of organic matter decreased with increasing in-barrel moisture (P < 0.01). The difference between reactive to total lysine decreased with increased in-barrel moisture, showing less lysine complexation with higher moisture contents (P < 0.05). Kibble expansion and lipid complexation showed a quadratic response (P < 0.01), with higher values for in-barrel moistures between 280 g/kg to 320 g/kg. Cat preferences to foods did not change due to water addition during extrusion. In-barrel moistures between 280 g/kg and 320 g/kg is suggested to improve extrudate formation, allow high starch gelatinization, and control mechanical energy application to the mass. Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias

Made available in DSpace on 2018-12-11T17:37:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 The aim of this study was to evaluate the effects of specific thermal energy (STE) application at the extrusion preconditioning stage on the processing parameters, starch gelatinization, kibble macrostructure, nutrient digestibility, feces characteristics, and palatability of a dog food formulation. Two experiments were conducted, and both used the same dog food recipe. In the first experiment, six amounts of STE were applied by changing steam infusion in the preconditioner to obtain the following discharge mass temperatures: 45 °C, 55 °C, 65 °C, 75 °C, 85 °C, and 95 °C. After evaluating the processing and kibble characteristics, the diets were fed to 36 dogs (six dogs per diet), and nutrient digestibility was determined by total feces collection. Palatability comparisons were carried out with 36 dogs using the two-pan method. Results were analyzed by analysis of variance (ANOVA), and means evaluated by polynomial contrasts according to the STE application (P < 0.05). In the second experiment, three treatments were produced. The extruder was operated with preconditioner mass temperature of 45 °C, and the amperage documented. On the sequence, the preconditioner mass temperature was increased to 95 °C, and the reduction on amperage was recorded. The extruder feed rate was them increased until a motor amperage equivalent to that of treatment 45 °C was observed but keeping constant preconditioner mass temperature at 95 °C. Processing and kibble characteristics were evaluated. Results were analyzed by ANOVA with means separated by Tukey's test (P < 0.05). In experiment one, a quadratic reduction of specific mechanical energy (SME) implementation with increasing STE was verified (P = 0.004), with a linear increase in total specific energy application to mass (P < 0.001). Regarding the relationship of starch gelatinization with increasing STE, a quadratic increase after preconditioning and a linear increase in kibbles after drying were verified (P < 0.001). Kibble expansion increased (bulk density, expansion rate, specific length), and hardness decreased with increasing STE (P < 0.001). Apparent nutrient digestibility and food palatability did not change according to STE application. Feces dry matter increased (P = 0.003), but pH and fermentation product content did not change. In experiment two, increasing STE was able to substantially elevate the mass production of the extrusion system while keeping the electric energy consumption constant. In conclusion, an increase in STE application decreased the SME required to process the food and increased the kibble expansion, starch gelatinization and in vitro digestibility of organic matter (OM), allowing a substantial increase in extruder productivity without increasing electric energy consumption, an important economic consideration for dog food production efficiency. Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal