Manure production and mineral excretion in feces of gilts fed ractopamine/Producao de dejetos e excrecao mineral nas fezes de femeas suinas alimentadas com ractopamina

A study was conducted to evaluate the feces +urine produced per animal (FUPA), dry matter, mineral matter, organic matter, nitrogen, phosphorus, potassium and sulfur in feces of gilts fed diets with increasing levels of ractopamine (0, 5, 10 and 15 mg [kg.sup.-1] of diet). A total of 468 finishing gilts were allotted into 36 pens. In two days of each week, feces and urine were daily sampled in four pens per treatment, quantifying the feces + urine. To determine the characterization of feces, two samples per week were taken daily, in nine pens per treatment. It was used a split plot design, considering the ractopamine level as the plot and the weeks as the subplots. There was no reduction in nitrogen amount in feces. An interaction was detected between ractopamine concentrations and weeks for FUPA and phosphorus, potassium and sulfur in feces. Ractopamine addition in diets for gilts has reduced the feces+urine production and nitrogen and phosphorus excretion. Higher values estimated for potassium content in feces of animals fed diets with 10 and 15 mg of ractopamine [kg.sup.-1] were found between the second and third week. Increasing levels of ractopamine from 5 to 15 mg [kg.sup.-1] promoted higher excretion of sulfur over the weeks of supply. Keywords: additive, environmental impact, finishing, mineral, Sus scrofa. Objetivou-se avaliar a producao de fezes + urina por animal e teores de materia seca, materia mineral, materia organica, nitrogenio, fosforo, potassio e enxofre nas fezes de suinos alimentados com dietas contendo concentracoes crescentes (0, 5, 10 e 15 mg [kg.sup.-1] de dieta) de ractopamina. Foram utilizadas 468 femeas suinas, alojadas em 36 baias de piso compacto. A cada semana foram realizadas duas colheitas diarias de fezes e urina, de quatro baias por tratamento e duas colheitas semanais, de nove baias por tratamento, para determinacao da composicao fecal. Utilizou-se o delineamento em blocos, em esquema de parcelas subdivididas, sendo as parcelas as concentracoes de ractopamina e as semanas como subparcelas. Nao houve reducao na quantidade de nitrogenio excretado. Observou-se interacao entre concentracao de ractopamina e semana, para a producao de fezes + urina por animal e para os teores de fosforo, potassio e enxofre nas fezes. A ractopamina na dieta reduz a producao de fezes + urina e a excrecao de nitrogenio e fosforo nas duas semanas iniciais. Foram encontrados maiores valores estimados para o teor de potassio nas fezes de animais ali