Ractopamina e ácido linoléico conjugado em dietas de suínos em terminação
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2013-12-13
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Universidade Federal de Goiás
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Aimed to evaluate the effect of ractopamine (RAC) and conjugated linoleic acid (CLA) in the diet on growth performance, digestibility of nutrients, blood parameters, carcass traits and fatty acid profile in pigs in the finishing phase . The experiments were carried out on Swine Industry, Department of Animal Production, School of Veterinary and Animal Science, Federal University of Goiás The digestibility experiment used 12 animals, 78 ± 3,6 kg (finishing phase). The design was a randomized block design with three treatments and four replicates per block, totaling 12 units. The treatments were: control diet , 8 ppm and 20 ppm of ractopamine conjugated linoleic acid. In the performance variables considered were weight gain , feed intake and feed conversion. The design was a randomized block design with three treatments and five replicates, totaling 15 experimental units, totaling 60 males castrated animals with approximate weights of 70 ± 2,9 kg. Data were subjected to analysis of variance and means of blocks submitted to the Student t test. The experimental period was 28 days until animals reached an average weight of 100 kg. The treatments were the same for the digestibility trial. A study was conducted of viability was observed taking into account economic indicators such as gross margin and profitability index. The evaluation of meat quality and fatty acid profile was performed from the longissimus muscle. For this, were slaughtered at random at the end of the performance experiment, one animal per treatment and per block, totaling 15 animals, these blood samples for analysis of hematological and biochemical profiles were performed. Found differences in digestibility of gross energy, with the highest level found in the control lies, the ration with ractopamine had higher rates found in the treatment with conjugated linoleic acid. Indices metabolization was no difference in coefficient metabozabilidade gross energy, coefficient metabozabilidade coefficient of dry matter and crude protein of metabozabilidade. The coefficient of gross energy metabozabilidade no difference between the control treatment and treatment with ractopamine, which are higher than the coefficient of gross energy metabozabilidade the clan. Metabozabilidade coefficient of dry matter was higher in the control diet compared to the other treatments and the coefficient of crude protein had metabozabilidade differences among treatments, being higher in the control treatment and the use of conjugated linoleic acid increased the metabolizable CP compared ractopamine. No differences in the variables, initial weight (IW ), final weight (FW), average daily gain (ADG), total weight gain (TWG) and feed conversion (FC) were observed in the different treatments tested. Food with 8 ppm of ractopamine decreased by 4,71 % in costs compared to the control diet and the diet with 20 ppm of CLA obtained an increase of 42,45% for ration with 8 ppm of ractopamine. In hematological parameters was observed (P> 0,05 ) for concentrations of leukocytes, with the reduction in the number of leukocytes with the use of ractopamine. Regarding the biochemical profile of blood plasma, it was found that the concentrations of AST were higher (P <0.05) than the reference value for pigs. Found no difference between treatments for the proximate composition of meat in moisture, crude protein and ether extract. There was difference among treatments for yield palette, being higher in the treatment with 8 ppm of ractopamine (4,31%), followed by the control diet (4,03%), and treatment with 20 ppm CLA (3,90%) the lowest income compared to others. Pigs had greater fat thickness at the 1st rib with 8 ppm of ractopamine, followed by treatment with 20 ppm of CLA, higher rates than control treatment. No significant differences were observed in the treatments with respect to the area of loin eye, moreover, the calculation of the ratio between area of loin eye/fat thickness and loin eye area/weight of half carcass showed no increase in the different treatments . both the initial pH and the final pH remained at levels greater than 6,0; suggesting condition meat (DFD meat dar, firm and dry) in all treatments. The profile of stearic acid (C18:00) had lower concentrations when used additives, and results in higher levels in the control diet. Since eicosapentaenoic acid (20:5 n -3) which are precursors of the series of leukotrienes 4 , 5 and 6 was obtained with the highest concentration in the diet ractopamine. To increase performance in pigs in the finishing phase ractopamine and CLA is not indicated, even ractopamine reducing diet cost . Diets with ractopamine and conjugated linoleic acid did not alter the carcass characteristics, both physical, sensory or proximate meat from barrows. The profile of stearic acid (C18:00) had lower concentrations when used CLA, and eicosapentaenoic acid (20:5 n -3) had the highest concentration in the diet with ractopamine. The ratio of saturated fatty acids:unsaturated lower levels when the diet contained the additives, with the lowest ratio when we used ractopamine.
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Rodrigues, Cláudia Paula de Freitas. Ractopamina e ácido linoléico conjugado em dietas de suínos em terminação. 2013. 93 f. Tese (Doutorado em Ciência Animal), Universidade Federal de Goiás, Goiânia, 2013.