Studies on Chromic Oxide-powder, Chromic Oxide-paper and Acid Insoluble Ash as Indicators in Digestion Trials with Pigs

Abstract

The present experiment was conducted to investigate the optimum length of the preliminary and collection periods when the chromic oxide-powder, chromic oxide-paper and 4 N-HCl insoluble ash (AIA) are used as indicators in digestion trials with pigs, and to compare the digestibility of total feces collection method with that of those indicator methods. Rations consisted of the following 3 diets: (A) commercial diet for young pigs; (B) diet generally used for the performance test for meat production in Japan; (C) diet B with 20% beet-pulp. Eight Landrace barrows were divided equally into two groups: pigs of one group were given diets A, B and C for 10, 14 and 14 days, respectively; and pigs of the other group were given diets A, C and B for 10, 14 and 14 days, respectively, in serial order. Four animals of each group were split into two lots. A pair of them was given the diet added chromic oxide-powder and another chromic oxide-paper contained approximately 40% chromic oxide, in which 0.2% of either chromic oxide-powder or chromic oxide-paper had been added to formula feed of diet B or diet C. The chromic oxide component in the feces for chromic oxide-powder or chromic oxide-paper method attained a steady state within 4 days after the ration was replaced. The days needed for a steady state of the AIA component in the feces was 4 days after the ration was replaced by diet B. By contrast, feeding diet C a case was observed that the AIA component in the feces did not come into equilibrium in less than 14 days. The coefficients of variation of apparent digestibility for each component in total collection method after 4 days preliminary feeding period decreased greatly during the first 3 to 4 days, but those of the indicator methods decreased slightly and there was little advantage with the extension of the length of collection period. This suggested that the collection periods of 1-2 days is enough for digestion trial by indicator method. Feeding diet B and C the fecal recoveries of the chromic oxide-powder were 95.9 and 95.1%, and those of the chromic oxide-paper were 94.3 and 96.5%, respectively. The digestibilities of dry matter, crude protein and energy determined by those two indicator methods were about 1% lower than those determined by the total collection method and an error of this size should probably be acceptable to most investigators. Feeding diet B the fecal recovery of AIA was 99% and the digestibilities determined by this method were practically identical to those obtained by the total collection method. But the fecal recovery of AIA was poor by feeding diet C.Jpn. J. Zootech. Sci., 55 (12) : [924][925][926][927][928][929] 1984 Jpn. J. Zootech. Sci., 55 (12): 924-929 929 1984

Acid‐insoluble ash as a marker compound for use in digestibility studies with humans

“…A possible alternative marker compound is acid-insoluble ash. The latter occurs naturally in foods and has been shown to be highly recoverable in the faeces of simple stomached animals (Sugimoto 1984;Wunsche et a1 1984). Many refined foods contain only low levels of acid-insoluble ash but the concentration of the marker can be increased by adding celite.…”