Avaliação nutricional do gérmen integral de milho para frangos de corte

• Autor(a) principal: LOPES, Elainy Cristina
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8099
• topic: Frango de corte; Nutrição animal; Gérmen integral de milho; CIENCIAS AGRARIAS::ZOOTECNIA

The objective of this study was to evaluate the chemical composition, energy values, performance, carcass characteristics and meat quality of broilers fed with increasing levels of corn germ meal (CGM). For this, two experiments were carried out by the Ethics Committee on the Use of Animals in the Research Laboratory with birds of the Department of Animal Science of the Federal Rural University of Pernambuco The first experiment was a metabolism test using 720 broiler chickens (Cobb 500) of one day of age, distributed in a completely randomized design, consisting of six treatments and six replicates of 10 (pre-initial phase - 1 to 8 days), 6 (initial phase – 15 to 22 days) and 4 birds (growth - 28 to 35 days) per plot. Experimental treatments consisted of a reference diet which was partially replaced by CGM in the 10, 15, 20, 25 and 30% portions. Partial excreta collection using the insoluble acidic indicator was used to determine the apparent metabolizable energy (AME) and corrected by the nitrogen balance (AMEn), apparent metabolizable coefficients of crude energy (AMCCE), dry matter (AMCDM), crude protein (AMCCP) and ethereal extract (AMCEE). The ileal content was also collected for the determination of ileal digestibility coefficients dry mater (IDCDM) and crude protein (IDCCP), digestible dry matter (DDM) and digestible crude protein (DCP). The second experiment was conducted with 648 chicks (Cobb 500) distributed in a completely randomized design with six treatments and six replicates, 18 birds per experimental unit. The treatments consisted of a control diet based on corn and soybean meal (0% CGM), and five diets tests with inclusion of CGM at 4, 8, 12, 16 and 20%. The birds and the feeds were weighed every seven days to define the feed intake (FI), weight gain (WG) and feed conversion ratio (FCR). At 42 days of age two birds per experimental plot were euthanized for evaluation of carcass weight and yield and commercial parts, viscera, abdominal fat and meat quality (pH, weight loss cooking, shear force, capacity water retention, color and peroxide index). The values of AME, AMEn, AMCCE, AMCDM, AMCCP and AMCEE were determined using the partial excreta collection methodology. The data from experiment 1 were analyzed using the response surface model and those from experiment 2 were submitted to analysis of variance (ANOVA) and adjusted for the regression of the broken line model and applied to the multivariate analysis in meat quality data. The stationary point for AME and AMEn was 4173 kcal/kg (AME = 1781.167 + 52.446 age + 203.455 level - 1.570 level x age - 4.119 level2), and 3591kcal/kg (AMEn= 1551.255 + 68.422 age + 196.686 level – 1.819 level x age -3.849 level2). To AMCCE, AMCDM, AMCEE the stationary point was 49.3, 40.4, 72.6 and 61.3%, respectively. The stationary point for IDCCP, IDCCM, DCP and DDM 78.88, 57.96, 8.50 and 56.17%, respectively. There was a difference for weight gain and feed conversion ratio for the total period (1 to 42 days), where the optimal weight gain for this phase was estimated at 2921 g/bird with inclusion level of 11.8% of CGM. There was no difference for the AME, AMEn and AMCCP of the diets. That increasing levels of CGM did not influence carcass weight and yield and cuts, and meat quality, however, they increased the weight and yield of gizzard and proventriculus. Increasing levels of CGM and the age of the birds influenced the energy utilization of the rations. The results of this research indicate that the inclusion of CGM in the broiler diet reduced performance at the highest levels. Low level CGM can be used in feeds for broiler chickens without jeopardizing zootechnical indexes.