Níveis de triptofano e piridoxina em dietas com redução de proteína bruta para suínos nas fases de crescimento e terminação

• Ano de defesa: 2015
• Autor(a) principal: Castilha, Leandro Dalcin
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Zootecnia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Suínos; Características de carcaça; Aminoácido aromático; Qualidade de carne; Comportamento animal; Brasil.; Aromatic amino acid; Animal behavior; Carcass traits; Meat quality; Brazil.; Ciências Agrárias; Zootecnia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1594

Two experiments were conducted to evaluate levels of digestible tryptophan and pyridoxine on performance,blood parameters and behaviorof barrows and gilts in the growing phase, and two experiments were conducted to evaluate levels of digestible tryptophan and pyridoxine on performance, blood parameters, behavior, quantitative and qualitative carcass characteristics of barrows and gilts in the finishing phase.Experiment I:sixty four crossbred barrows with an average initial weight of 50.08 ± 1.82kg were distributed in a randomized complete block design in a 2 X 4 factorial design, with two levels of pyridoxine (1 and 5 mg / kg) and four levels of digestible tryptophan (0.142, 0.169, 0.196 and 0.223%), with eight replications and one animal per experimental unit.There was a quadratic effect (P=0.024) of digestible tryptophan levels on backfat thickness (BT) and the regression (R²=0.78) pointed to the lower value of BT (0.98cm) at the level of 0.195% digestibletryptophan. There was a quadratic effect (P=0.024) of tryptophan levels of plasma triglycerides which higher value (42.42 mg/dL) was estimated (R²=0.77) at the level of 0.184% digestible tryptophan. Plasma urea was positively influenced (P=0.019), while total protein levels were negatively influenced (P=0.002) by the additional level of pyridoxine. The level of 0.142% tryptophan met the requirements of barrows, from 50 to 70 kg, based on performance, carcass characteristics, blood parameters and behaviour, resulting in a daily requirement of 3.14 g of digestible tryptophan. Moreover, the additional pyridoxine did not influence the tryptophan requirements.Experiment II: sixty four crossbred gilts with an average initial weight of 49.17 ± 1.86kg were distributed in a randomized complete block design in a 2 X 4 factorial design, with two levels of pyridoxine (1 and 5 mg / kg) and four levels of digestible tryptophan (0.150, 0.178, 0.206 and 0.234%), with eight replications and one animal per experimental unit. The longissimus dorsi muscledepth (MD) had a positive effect (P=0.020) of the additional level of pyridoxine (5 mg/kg). In addition, there was an interaction (P=0.005) between the levels of tryptophan and pyridoxine for MD, wherein the additional pyridoxine provided to the higher MD at 0.178% digestible tryptophan. The supplemental pyridoxine also increased (P=0.038) plasma creatinine. Tryptophan levels influenced quadratically (P=0.033) plasma urea, with estimates (R²=0.64) of lower value for the level of 0.181%. The pyridoxine levels did not affect the digestible tryptophan requirement for gilts from 50 to 70 kg, which is a maximum of 0.150%; resulting in a daily requirement of 3.11 g.Experiment III:sixty four crossbred barrows with an average initial weight of 70.77 ± 2.07kg were distributed in a randomized complete block design in a 2 X 4 factorial design, with two levels of pyridoxine (1 and 5 mg / kg) and four levels of digestible tryptophan (0.130, 0.155, 0.180 and 0.205%), with eight replications and one animal per experimental unit. The behavioral evaluation revealed decreased linearly effect (P=0.003) of tryptophan levels on the behavior of sleep and and quadratic effect (P=0.008) on eating behavior, both in nighttime.For quantitative variables of carcass, although pyridoxine has shown positive effect (P <0.05) on yield of hot and cold carcass, resulted in a negative effect (P <0.05) on the ham weight and yield. For qualitative variables of longissimus dorsi, although pyridoxine has shown positive effect (P <0.05) on pH 24h, it increasedthe loss of drip and cookingfluid. The dietary digestible tryptophan requirement for barrows from 70 to 100 kg was not higher than 0.130%(4.07 g/day) and did not change due pyridoxine.Experiment IV: sixty four crossbred gilts with average initial weight of 70.52 ± 2.95kg were distributed in a randomized complete block design in a 2 X 4 factorial design, with two levels of pyridoxine (1 and 5 mg / kg) and four levels of digestible tryptophan (0.140, 0.167, 0.194 and 0.221%), with eight replications and one animal per experimental unit. The eating behavior in daytime was negatively influenced (P=0.003) by the additional level of pyridoxine. For behavioral evaluation in nighttime increasing levels of tryptophan influenced (P=0.001) linearlydecreasing the sleeping behavior. The pyridoxine supplementation increased (P<0.05)the relative weight of heart but decreasedthe plasma urea, the pH measured 24 h after slaughter and the liquid loss by boiling. Pyridoxine levels did not affect digestible tryptophan requirement for sows, from 70 to 100kg, which is less than 0.140% or 3.53 g/day.