Differential compensatory organ growthin young pigs after short-term rehabilitation from protein deficiency

Abstract

Our objective was to determine the changes in body composition and organ mass in response to severe dietary protein restriction and short-term rehabilitation. Six-week-old pigs were fed ad libitum either a nutritionally adequate (A, 21% protein, n=4) or a protein-deficient (D, 5% protein, n=4) diet for 8 week, then all pigs were fed the adequate diet for 5 week. Body weight remained less after the 5 week repletion period in D pigs than in A pigs; relative weights of cerebrum, heart, small intestine, and large intestine, but not of stomach, liver, kidneys or spleen, were greater in D than in A pigs. Plasma total protein, albumin, Ca, and inorganic P were depressed and plasma HDL-cholesterol and K were elevated by protein depletion, but restored to normal levels after 5 week of repletion. Percentage of body fat was greater and that of non-osseous lean was less in in D pigs after 8 week of depletion than in A pigs (dual energy x-ray absorptiometry, DXA), but values for D pigs after 5 week of repletion were similar to those of A pigs; whole body chemical analysis after repletion corroborated the terminal DXA data. Our results suggest that changes in body composition induced by 8 week of severe protein restriction are restored after 5 week of rehabilitation to values similar to those of age-matched, adequately fed pigs, and that non-allometric growth of selected organs occurs during repletion as a compensatory response in young, growing animals.