Efeito da suplementação de arginina e lisina sobre o crescimento, imunidade e metabolismo muscular e ósseo de frangos de corte

• Autor(a) principal: Fernandes, Jovanir Inês Müller
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1539
• topic: Frango de corte; Qualidade óssea; Arginina; Lisina; Sistema imune; Células satélite; IGF-I; Brasil.; Broilers; Bone quality; Arginine; Lysine; Immune system; Satellite cells; IGF-I; Brazil.; Ciências Agrárias; Zootecnia

Effect of arginine (Arg) and lysine (Lys) supplementation was evaluated in two trails during the initial diet on the productive characteristics, metabolism and growth bone, muscle and lymphoid organ development and skin and intestine morphometrics of broiler chickens. The first trial evaluated the effect of antagonism between Arg and Lys on performance, skin morphometrics and plasma levels of IGF-I and its consequences on the metabolism and growth bone of broiler chickens. One thousand seven hundred and seventy-six male Cobb broilers were reared in a randomized factorial four x four design (Lys and Arg levels) with two replications of 55 birds each. Experimental diets were formulated to contain 1.189%; 1.427%; 1.665% and 1.902% digestible Lys levels and 1.217%; 1.416%; 1.615% and 1.814% digestible Arg levels. Arg level addition increased the diameter, density, bone.s total cortical thickness. However, extreme levels of Arg in the initial phase increased (p<0.05) the hypertrophic zone cartilage of growth plate and alkaline phosphatase activity on the 42nd day. On the other hand, the lysine positively affected (p<0.05) bone strength, although it may have also contributed negatively towards tibial dyschondroplasia. This positive effect of the lysine on bone tissue may be related to the production of collagen as seen by the increase (p<0.05) of IGF-I levels in Lys supplementation. Arg did not alter IGF-I, probably owing to Lys degradation, which inhibited their secretagogo role in mammals. Bone parameters evaluated at the finish of growth phase (22-42 days) were influenced by amino acids which supplemented the initial diet. There was an interaction (p<0.05) between Lys and Arg levels to weight gain and feed:gain ration, demonstrating that Lys levels above the recommended ones decreased broilers. weight. Such effect pay be lowered by the addition of extremely high Arg levels. The productive characteristics in the growth phase (22 - 42 days) were affected by supplementation in the initial diet. Mortality increased (p<0.05) in response to Lys and Arg supplementation. On the other hand, the addition of levels above the requirement of both amino acids in the initial phase contributed positively (p<0.05) towards the thickness of the 42-day-old broiler chickens. derpal skin layer. This is probably due to the involvement of Arg and Lys in collagen biosynthesis. Extreme amino acid levels may be harmful to performance owing to diet imbalance and highest energy expenditure in metabolism and excretion. Excess Lys may still be involved in Arg degradation in ornithine and urea, which modifies the nitric oxide synthesis. In the second trial, the effect of Arg supplementation in the initial diet on the behavior of productive characteristics, skeletal muscle fibers and lymphoid organ development and intestinal mucosa morphometrics of the broiler chickens was evaluated. Nine hundred and ninety male Cobb broilers were reared in a complete randomized design with five treatments and six replicates with 33 birds each. Dietary treatments consisted of one basal diet (Arg not supplemented) and four supplemental digestible Arg levels (1.390%; 1.490%; 1.590%; 1.690% and 1.790%), maintaining a relationship with Lys of 1.103; 1.183; 1.262; 1.341 and 1.421%, respectively. The addition of Arg levels improved (p<0.05) body weight and feed:gain ratio, without modifying the birds. consupption in the initial phase. However, this effect was not reported (p>0.05) till the end of the growth phase in which fowls did not receive Arg supplementation in the diet. Supplementation of recommended levels may be thus necessary so that the broiler chickens produce maximum performance. The positive effect (p<0.05) of Arg supplementation on lymphoid organ weight was more evident during the first week for spleen and Fabricius bursa, while the thymus still answered positively until the end of the initial phase. No effect (p>0.05) of Arg on the length and weight of the small intestine in any evaluated age was reported. However, relation vilo:cripta of the duodeno in the first week increased (p<0.05). These findings suggest that Arg supplementation improved these characteristics, probably by increasing ornithine levels, due to the extra substrate availability for polyamine synthesis. A positive effect (p<0.05) of dietary Arg supplementation was recorded on weight breast and breast fillet weight and diameter skeletal muscle fibers. There was, however, o significant effect on protein:DNA ratio which suggested that Arg levels did not activate the satellite cells via IGF-I. On the other hand, dietary Arg supplementation improved breast growth of chicks by the end of the initial phase. In the initial phase dietary Arg supplementation did not affect (p>0.05) carcass yield up to the 42nd day. Dietary Arg supplementation of the levels currently recommended for the growth phase may be required for the muscle development of broiler chickens.