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Biomedical subjects

R L Kirkpatrick

Publications and source records attributed to R L Kirkpatrick.

35 records · Page 2Linked to original sources

Ectopic fetuses in two cottontail rabbits.

Mummified fetuses were discovered in the abdominal cavities of two cottontail rabbits (Sylvilagus floridanus) collected during separate years from the same geographical location in Virginia. One of these rabbits had a patent opening through the vaginal wall to the abdominal cavity. The uterus and vagina of the second rabbit appeared normal.

Animals↗

Effects of a polychlorinated biphenyl (PCB) on sleeping times, plasma corticosteroids, and testicular activity of white-footed mice.

Forty adult male white-footed mice (Peromyscus leucopus) were divided into four equal groups and fed diets containing 0, 100, 200 or 400 p.p.m. of a polychlorinated biphenyl (PCB) for 2 weeks. PCB ingestion increased liver weights and reduced pentobarbital-induced sleeping times at all levels tested, indicating increased hepatic microsomal enzyme activity. Plasma corticoid levels, seminal vesicle weights and testicular spermatozoa numbers were reduced at the 400 p.p.m. level.

Adrenal Cortex Hormones↗

Effect of tannins on galliform cecal partitioning.

Winter diets of ruffed grouse (Bonasa umbellus) and other galliformes are high in tannins. We fed quebracho, a condensed tannin, to ruffed grouse and found no effect on dry matter intake or body mass at levels up to 6% of the diet. However, a high-fiber diet with 8% quebracho resulted in reduced dry matter intake and body mass loss. Grouse could not tolerate a diet with 8% tannic acid, a hydrolyzable tannin, which caused a large reduction in dry matter intake and body mass. Northern bobwhite (Colinus virginianus) and ruffed grouse responded to dietary quebracho tannin by increasing the proportion of digesta that was excreted from the ceca. In the northern bobwhite, 59%-76% of the tannin recovered from the feces was in cecal feces. There was no difference in average passage rates of liquid and fiber digesta, although variation was high in tannin-fed birds. The role of the ceca in handling tannin requires further investigation.

Animals↗

Effects of tannins on digestion and detoxification activity in gray squirrels (Sciurus carolinensis).

Acorn tannins may affect food preferences and foraging strategies of squirrels through effects on acorn palatability and digestibility and squirrel physiology. Captive eastern gray squirrels (Sciurus carolinensis) were fed 100% red oak (Quercus rubra) or white oak (Quercus alba) acorn diets to determine effects on intake, digestion, and detoxification activity. Red oak acorns had higher phenol and tannin levels, which may explain the lower dry matter intakes and apparent protein digestibilities and the higher glucuronidation activities observed in squirrels. Although the white oak acorn diet had lower apparent protein digestibilities than the reference diet, it did not suppress dry matter intake for a prolonged period or stimulate glucuronidation. Negative physiological effects of a 100% red oak acorn diet suggest gray squirrels may require other foods to dilute tannin intake and provide additional nutrients. To distinguish the roles of different tannin types in the observed effects of acorn diets on squirrels, squirrels were fed rat chow containing no tannins, 4% or 8% tannic acid (hydrolyzable tannin), or 3% or 6% quebracho (condensed tannin). Apparent protein digestibilities were reduced by tannic acid and quebracho diets. Only the 8% tannic acid diet tended to increase glucuronidation. Specific effects of tannins may largely depend on tannin type, composition, and source and on other nutritional and physiological factors.

Animals↗