Suplementação de diferentes fontes e níveis de cobre e seus efeitos para frangos de corte

Abstract

In this study, we used 1,440 broiler chicks from Cobb lineage housed in experimental avian, adopting a DIC in factorial 2x2 + 2 with six repetitions per treatment to evaluate the effects of supplementation of two sources of copper (Cu) (copper sulfate (CuSO4) and copper complexed to 2-Hydroxy-4- methylthiobutanoic acid (Cu(HMTBa)2)) associated with two levels (30 and 100mg/kg) plus two additional treatments: positive control (CP enramycin , 10mg/kg) and negative control (CN - free improver performance additive). In both additional treatments (CP and CN), copper was included in the diets at levels considered normal (10 mg / kg) to meet the nutritional needs of this element. Performance characteristics were evaluated: bone mineralization, biometrics and intestinal morphology as well as immunological characteristics of broilers. Performance results in the initial phase demonstrated that there was interaction (P<0.05) between the sources and levels of Cu studied indicating that when using a lower dose of Cu, the CuSO4 source provided higher feed intake (CR, 1- 10 and 1-22 days) and weight gain (GP, 1-10 days). Performance results in the initial stage demonstrated that there was interaction (P<0.05) between the sources and levels of Cu studied indicating that when using a lower dose of Cu, the CuSO4 source provided higher feed intake (CR, 1- 10 and 1-22 days) and weight gain (GP, 1-10 days). On the other hand, when using (Cu(HMTBa)2) as a source of Cu, the birds subjected to diets supplemented with 100mg/kg Cu showed higher CR (days 1-10 and 1-22) and PG (1-10 days) compared to those submitted to the lowest evaluated level. The feed conversion (FC) of the birds in the pre-initial stage, was only influenced (P<0.05) by the copper level with the best response observed in higher level (100mg / kg) of copper. Considering the final stage of breeding (1-38 days), the highest level of Cu in the diets increased (P<0.05) the CR of broilers. Birds supplemented with Cu at higher levels (30 and 100 mg/kg) showed a higher GP and better FC compared to birds of the additional treatments. There was no effect of treatments carried out on bone mineralization (ash content, calcium and phosphorus in tibia) and length of tibia of broiler chicks (P>0.05). There was interaction between source and level of Cu for the weight of the tibia and the Seedor index indicating that broiler fed with the highest level of Cu from the source Cu(HMTBa)2 tibias showed a lower weight and density. The relative length and weight for the duodenum and ileum, respectively, were higher (P<0.05) in birds fed (Cu(HMTBa)2). The use of 30mg/kg of Cu provided higher (P<0.05) relative weight to the jejunum. Supplementation of Cu at higher levels (30 and 100 mg/kg) caused an increase (P <0.05) in villus height and ileum compared to the birds of the additional treatments impacting on the increase of the ileal absorptive surface, and the same happened to jejunum. Broilers fed with high Cu levels feed showed greater depth of jejunum and ileum crypt in relation to those of the additional treatments. The production of nitric oxide (ON) at the 23th day was affected (P<0.05) for the sources and Cu levels. With higher production (P>0,05) of the metabolite in groups at level 30 mg/kg Cu supplementation, the same occured with the source CuSO4 compared to the source (Cu(HMTBa)2). After 38 days, the production of ON and mitochondrial metabolism (MTT) were higher in the groups supplemented with lower levels of Cu (30mg/kg) compared to those with higher levels of Cu. The average production of nitrous oxide, as well as MTT, for birds at 38 days using Cu were higher compared to those observed in birds of additional treatments. Broilers supplemented with a lower level of CuSO4 source had lower (P<0.05) MTT after 38 days. The results demonstrate the efficiency of Cu use on the performance of broiler chickens showing that the level of supplementation and the source of Cu used may generate different answers on performance, biometrics and intestinal morphometry, as well as in the production of ON and MTT mononuclear cells from peripheral blood.