Date of Award:

1967

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Animal, Dairy, and Veterinary Sciences

Department name when degree awarded

Toxicology

Advisor/Chair:

Joseph Blake

Abstract

It was hypothesized that the hypocalcemia, hyperphosphoremia, hyperkalemia and the mild hypochromic microcytic anemia which existed in cattle afflicted with brisket disease could be due, at least in part, to nutritional disturbances. A chemical composition study was made of seven monocotyledonous plant species that comprise a major part of the diet and nine dicotyledonous plant species consumed by cattle and known or suspected of being poisonous. The plants analyzed we re collected from two cattle grazing allotments, 7-mile and UM, in the Fishlake District, Fishlake National Forest, Utah, where brisket disease incidence is high. In each species the percentages on dry matter basis, of calcium, magnesium, potassium, sodium, copper, cobalt, iron, manganese, molybdenum, zinc, chloride, phosphorus and oxalate were determined.

The first ten elements listed were measured by atomic absorption spectrophotometry by modifications of the methods used by Allan (1961 ) and David (1962). Oxalate content was determined by a modification of the method used by Dye (1959). Phosphorus content was determined colorimetrically by a modification of the method used by Fiske and SubbaRow (1925).

Chloride content was determined by a micro-titration method used at U.S. Salinity Laboratories.

Results obtained showed that the monocotyledonous plant species were low in calcium content when compared to values reported in the literature for grass and legume species and when compared to calcium requirement for beef cattle. The hypothesis that hypocalcemia in cattle afflicted with brisket disease is due to inadequate dietary intake gains support. The quantities of oxalates in the plant species studied were substantial enough to depress an already low dietary calcium level. It was not determined if oxalate ingested was of sufficient magnitude to cause renal and nervous lesions and erythrocyte destruction.

Potassium content of the monocot species in the plant study was high compared to plants that normally comprise cattle diets and hyperkalemia in cattle afflicted with brisket disease could be of dietary origin. Sodium content of each of the plants studied was below the level required to satisfy body needs and could not be responsible or contributary to the edema that occurs in brisket disease.

The plant species contained large quantities of iron, manganese and copper, much in excess of nutritional requirements. The anemia that accompanies brisket disease could be related to dietary excesses of these elements. Zinc requirement in cattle is not known, but if the requirement is comparable to that of swine, the plants studied provide an adequate quantity of this element. The contents of cobalt and molybdenum were too little to be measured by atomic absorption spectrophotometry. There may be a cobalt deficiency in cattle grazing these forages.

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Toxicology Commons

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