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Biomedical subjects

D L Kolstad

Publications and source records attributed to D L Kolstad.

6 recordsLinked to original sources
PubMed1984

Fluoride tolerance of the young chick and turkey poult.

Duplicate groups of Strain-Cross White Leghorn chicks, White Rock Cross broiler chicks, and Large White Turkey poults were fed from 0 to 800 ppm fluoride as NaF for 1 day to 6 weeks. Based on growth rate, the dietary fluoride tolerances were at least 400 ppm for Leghorn chicks, 300 ppm for broiler chicks, and 200 ppm for turkey poults. Fluoride ingestion did not affect bone morphology or breaking strength. Increases in fluoride content of bone ash, plasma, and other soft tissues were related to dietary fluoride level but not to type of bird. Bone ash fluoride content was relatively constant at a given fluoride intake level over exposure periods of from 2 to 6 weeks.

Aging↗
PubMed1978

Bovine dental fluorosis: histologic and physical characteristics.

Incisor teeth from 5- to 6-year-old Holstein-Friesian cattle maintained on a ration averaging 40 ppm F annually from 4 months of age were analyzed by a variety of histologic techniques. These techniques included photomicroscopy, microradiography, protein staining, and microhardness testing. The features of fluorotic enamel that were noted were: hypomineralized outer enamel, coronal cementum hyperplasia, disrupted subsurface pigment band, hypoplastic pits, puckered incremental lines, periodic radiolucent regions, positive protein staining, and decreased microhardness of the outer enamel. These results were similar to the lesions of dental fluorosis observed in other species, and explain the external appearance of fluorotic bovine teeth observed under field conditions.

Animals↗
PubMed1978

Electron probe microanalysis of fluorotic bovine teeth.

Incisor teeth were obtained from adult cattle which since 4 months of age to 5 or 6 years were maintained on rations containing a yearly average of 40 ppm F in the forage. Microchemical analyses were performed on the fluorotic bovine incisors. The microdistribution of fluoride varied markedly at different sites within the same tooth. Fluoride concentrations varied with the depth from the tooth surface and were influenced by the concentrations of fluoride present in the forage during amelogenesis, and the presence of hypoplastic pits and hyperplastic coronal cementum in enamel. The cementum in these lesions contained remarkably high concentrations of fluoride, and it was less calcified and more porous than adjacent enamel.

Animals↗
PubMed1977

Effects of dietary fluoride ingestion on ration intake and milk production.

The influence of 1-mo ingestion of a ration containing 50, 100, 150, or 200 ppm fluoride (as sodium fluoride) on milk production and ration intake of Holstein cows was studied. The total amount of fluoride administered was mixed into the grain mix and fed twice each day. The concentrations of fluoride in plasma and urine were related to the concentration of fluoride in the ration. There was no effect of fluoride on hay intake, but there was a decrease in intake of the grain mix at an intake of 200 ppm fluoride. The ingestion of 150 or 200 ppm fluoride for 1 mo had a slight adverse effect on milk production. From these results we suggest that rations containing less than 150 ppm fluoride will not influence ration intake or milk production adversely if they are fed for a short time to mature cattle not suffering from other long-term adverse effects of fluoride ingestion.

Animals↗
PubMed1976

Effect of dietary fat on fluoride absorption and tissue fluoride retention in rats.

The effect of dietary fat on fluoride toxicity was investigated in rats fed isoenergetic diets with graded levels of fat (0, 10%, 30% or 50% of energy) containing 400 ppm fluoride. Growth rate was depressed in all groups receiving fluoride but most severely in the 50% dietary fat group. Plasma, liver and femur fluoride concentrations were increased by increasing dietary fat. This was apparently due to increased absorption of fluoride, since urinary fluoride increased and fecal fluoride excretion decreased as fat intake was elevated. The enhancement of fluoride absorption by fat is believed to be due to the delaying effect of fat and fluoride on gastric emptying, thereby allowing more time for the fluoride to be absorbed from the stomach.

Absorption↗