Japanese Journal of Veterinary Research;Volume 6, Number 1

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BIOCHEMICAL STUDIES ON SO-CALLED OSTEOMALACIA (OSTEODYSTROPHIA FIBROSA) IN HORSES III. : SOME FACTORS RELATING TO CHANGES IN THE COMPOSITION OF THE BONE

USHIJIMA, Jun-ichi

Permalink : http://hdl.handle.net/2115/1723
JaLCDOI : 10.14943/jjvr.6.1.11

Abstract

Few biochemical studies on the bone of domestic animals have so far been made, and fundamental figures which are necessary for this kind of study are difficult to be found in literature. Even though the bone is apparently seen as normal, its chemical composition may be physiologically changed by various conditions. The present report deals with investigations on some influential conditions respecting the bone composition. 1. The Age of the Animal and Bone Composition (Table 1) The analytical results of 44 samples from each of os nasale and metacarpus, which are divided into 4 age groups by origin, 1〜3,4〜8,9〜14 and over 15 years, indicated the reduction of water, the increase of bone ash, and the slight increase of phosphorus, calcium, calcium/nitrogen ratio and specific gravity of dried bones. However, the content of total nitrogen, magnesium and the ratio of calcium/phosphorus did not show any changes in company with ages of animals. It may be considered that the growth of organic matrix takes place in relatively young years and that the degree of calcification increases with the age of animals. 2. Different Districts as Growth Environment and Bone Composition (Table 2) Comparison was made employing 30 cases of horses which had been kept in rice-paddy areas and field-crop areas. From the results of analyses, it might be said that the degree of calcification of the bones in animals kept in field-crop areas is somewhat higher than in cases from rice-paddy areas, but without showing statistically significant differences except for calcium in metacarpus. 3. Comparison of Bone Composition between Os nasale and Metacarpus (Tables 1,2 and 3 ; Figs. 1,2,3 and 4) The contents of mineral substances, except magnesium, are markedly higher in metacarpus than in os nasale. However, the content of total nitrogen indicates scarcely any differences between the two bones. As shown in calcium/nitrogen ratios, the degree of calcification in metacarpus seems to be markedly higher than that in os nasale. Further comparisons were made between bone composition of these two parts of the diseased bone affected by osteodystrophia fibrosa. The degree of compositional changes in this disease is distinctly different in these two bones even though the general tendency of the changes is similar. In spite of the severe reduction of bone salt in os nasale, the reduction in metacarpus remains slight. These facts may indicate that the degree of calcification in metacarpus is markedly higher than that in os nasale ; moreover, in comparison with os nasale, this disease does not manifest itself as distinctly in metacarpus.

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