Balanços eletrolíticos da ração sobre características ósseas de frangos de corte

• Autor(a) principal: Müller, Elisa Sialino
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/300
• topic: Frangos de corte; Balanço eletrolítico; Característica óssea; Broilers; Electrolite balance; Bone characteristic; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::METABOLISMO E BIOENERGETICA

The aim of this study was to evaluate femur quality of broiler chicks fed different dietary electrolite balance (EB). Two experiments were conducted. In the first, 936 day old chicks, male, Cobb, were used and fed with corn and soybean meal rations. The experimental design was randomized blocks with six treatments, six replicates with 26 chicks per experimental unit. The dietary treatments were obtained by the addition of NH4Cl to the basic ration in order to have five EB levels (-50; 0; 50; 100 and 150 mEq/kg). In the second experiment, 720 day old chicks, male, Cobb, were used and fed with basal ration with adition of K2CO3 and NaHCO3 to obtain five EB levels (200; 250; 300; 350 e 400 mEq/kg). The experimental design was in randomized blocks with five dietary treatments, six replicates and 24 chicks per experimental unit. At seven, 14, 21 and 42 days of age one chick from each box was sacrificed and both femurs were removed. The levels of collagenous (CP) and noncollagenous proteins (NCP), ash and ash minerals (Ca, P, Mg, K and Na) were determined. Also some geometrical and mechanics aspects were studied. Chicks, at seven days of age fed 200 mEq/kg of EB had femurs with the highest weight of fat-free dried bone and transversal section area (P<0.05). Also, in the same age, Ca and P contents were similar (P>0.05) in femurs of chicks fed 150 mEq/kg and 200 mEq/kg of EB and they were higher than those from chicks fed the other EB levels (P<0.05). Mg content were higher in chicks femur fed 200 mEq/kg of EB that the other levels (P<0.05). The highest Ca:P ratios were observed in femur from chicks fed 0 and 50 mEq/kg and the lowest ash content was oberved in chicks femur fed 200 mEq/kg of EB (P<0.05). Feeding the chicks with 200 mEq/kg of EB resulted in femurs with the lowest Ca content at 42 days of age (P<0.05). Also in this age, femur Ca:P ratios were similar in chicks fed 150 mEq/kg and 200 mEq/kg of EB and these results were higher than those observed with chciks fed the others EB levels (P<0.05). Femur CP contents were similar (P>0.05) in chicks with 21 days of age and fed 150 and 200 mEq/kg of EB and higher than the others treatments (P<0.05). Femur chicks fed 200 mEq/kg of EB with seven days of age had the highest bending strenght value in the flection (P<0.05). Femur chicks fed 50 mEq/kg of EB with 21 days of age had the highest modulus of elasticity (P<0.05). Chicks at seven days of age were more sensible by dietary EB variation than those older. The animals at 14, 21 and 42 days old in experiment 1 and in all ages of experiment 2 were less affected by EB levels tested. Then, its possible to infer that the optimal levels of EB include a range and not a specific value for these ages. However, for animals at seven days is safest to use 200 mEq/kg of EB.