Efeito da ractopamina e fitase sobre o desempenho e características de carcaça de suínos em terminação

• Autor(a) principal: Corassa, Anderson
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1909
• topic: Ractopamina; Fitase; Suíno; Terminação; Ractopamine; Phytase; Finishing pigs; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

Two experiments were conducted to evaluate the effects of the ractopamine and phytase on the performance and carcasses characteristics of finishing pigs. In the first experiment were used 354 barrows with high genetic potential of only one origin and with initial weight of 94,1± 5,7 kg, in a randomized experimental block design, with six treatments, and five replications, four containing twelve and one with eleven animals for experimental unit. The treatments were: (C) control diet based on tables of nutritional requirements; (A) same C with nutritional adjustment for ractopamine; (AF) same A with phytase without considering values of liberation of phytic calcium and phosphorus by enzyme (valorization); (AR) same A with ractopamine; (ARF) same A wit ractopamine and phytase without valorization; and (ARFV) same A with ractopamine and phytase with valorization. After 21 days the animals were abated for evaluation of carcasses. Analysis of the treatments was realized through orthogonal contrasts. Feed intake was not influenced by the diets. The increase of the proteic and amino acidic levels of the diet harmed performance from 14 to 21 days but it didn't alter the carcasses. There was effect of the ractopamine in average daily gain and feed:gain at the end of the period of 21 days, besides the pre-slaughter weight, hot carcass weight, carcass yield, total fat-free lean and payment index. Larger levels than the requirements of the animal category of calcium and phosphorus available match by phytase inclusion didn't present effect in diets containing ractopamine. Ractopamine improved performance and carcass characteristics. Performance and carcass characteristics were maintained when values of liberation of phytic minerals were used by the fitase in diets with ractopamine. In the second experiment were used 240 barrows with initial weight of 100,7± 3,9 kg, distributed in 2 x 3 factorial arrangement, with two ractopamine levels (5 and 10 ppm) and three phytase levels (0, 500 and 750 FU). The experiment had duration of three weeks and at the end the animals were slaughter for carcass evaluation. There was not interaction between ractopamine and phytase levels in none of the variables. Corporal weight, feed intake, farm to slaughter shrink and fat free lean percentile were not influenced by the treatments. Pigs fed with diet containing 10 ppm of ractopamine present better results of daily gain, feed:gain, hot carcass weight, total fat free lean, payment index and revenue that those fed with 5 ppm. Phytase levels didn't influence performance and carcass characteristics, except better carcass yield of 500 UF that without phytase. The conclusion was that ractopamine improved performance and carcass characteristics, diets with ractopamine formulated with inorganic phosphate or fitase with valorization haven t differences in performance and carcass characteristics, diets with ractopamine containing fitase with or without valorization don't influence performance and carcass characteristics, except the payment index. Diets with 10 ppm of ractopamine present better performance and carcass characteristics that diets with 5 ppm, and the substitution of inorganic source for phytase with 500 or 750 UF didn t influence performance and characteristics of carcasses of pigs fed with ractopamine.