Thesis of chromic oxido in gelatine capsules for the assay of digestibility in Leghorn cockerels

Abstract

In the work, the author studied the chromic oxide method for determining dry matter digestibility, administering the index substance in gelatine capsules and in the ration. The 105- days old Leghorn cockerels were divided into four lots, two of which consumed 200 mg of chromic oxide, daily, and the ethers received it in the ration at 0,26% on dry weight basis. The faeces were collected twice a day according to the following scheme: 1) faeces collected at 7 A.M. - equivalent to 1/3 of the total excretion; 2) faeces collected at 18 P.M. — equivalent at 1/3 of the total excretion; 3) faeces collected during 24 hours periods — 1/3 of the two collection made at 7 A.M. and 18 P.M.; 4) total faeces: 1/3 of each collection made at 7 A.M. and 18 P.M. during 5 days.
1) The differences found between methods — conventional and chromic oxide — were highly significant.
2) On the other hand, the two ways of chromic oxide administration in mixture with the ration and in gelatine capsules —were highly significant as well.
3) In spite of the indicator method showed higher variation —about 15% — in comparison with the conventional one — about 8,5% — the digestibility coefficients exhibited more uniform values between replicate treatments.
4) The recovery tests were higher — 84% — in the two lots that received the index substance in the ration.
5) Since the recovery tests utilized were very much influenced by the errors inherent in the food intake and faeces collection control the low values obtained confirm some low results contained in the literature.
6) It appears, that is valid to conclude that the chromic oxide administration in gelatine capsules did not offer advantages in this kind of investigation.