Model of the biological flow of phosphorus from phosphate sources in pig, using 32P as marker

[摘要] - The experiment was designed to simulate the mathematical models that relate to the phophorus (P) flow, considering the hypotheses that the endogenous phosphorus from digestive tract was absorbed in the same proportion of the dietary phosphorus and that the input and output flow of this mineral in the compartments was constant. The variables absorption, retention, endogenous P that returns to the gastrointestinal tract (GIT), dietary absorbed P, accretion, reabsorption and balance of P in bone and in soft tissues and P from bone and soft tissue and from the total absorbed that returns to GIT, in growing pigs fed diets containing P from different phosphate sources were evaluate. The model was deterministic and compartmental, in which the GTI (C1), bones (C2) and soft tissues, liver heart, kidney and muscle, (C3) represented the compartments. The information on metabolism and kinetics of the P in tissues obtained by isotopic dilution technique was used. It was concluded that: the hypotheses established in the model were coherent and the obtained values were adjusted to the P flow in pigs; the variables P intake, endogenous P that return to the GIT, P retention, dietary absorbed P, accretion, reabsorption and balance of P from bone and soft tissues and P from total absorbed that returned to the GIT were not influenced by the P from the phosphates sources; the dietary phosphorus could interfere on P distribution in the tissues after the process of absorption of that mineral; the P from total absorbed that return to the GIT was proportional to P intake.

[学科分类] 兽医学

[关键词] endogenous losses;kinetics;mineral metabolism;phosphorus accretion;radiophosphorus;true absorption   IntroduçãoA despeito das óbvias diferenças entre espécies;muitos critérios são usados para avaliar a utilização de fósforo nos alimentos;incluindo ganho de peso;eficiência alimentar;resistência à quebra do osso;cinza no osso;fósforo no soro sangüíneo;anormalidades no esqueleto;densidade do osso;distribuição do fósforo em tecidos;atividade da fosfatase alcalina;tamanho da leitegada;balanço metabólico e a taxa de incorporação e a biodisponibilidade;por meio da técnica da diluição isotópica (KLEIBER et al