Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: Ronald Fayer x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

The effects of coliform endotoxin (e) and recombinant bovine tumor necrosis factor α (tnf) were compared with respect to clinical signs of disease and changes in plasma metabolite and pituitary and pancreatic hormone concentrations in calves. In addition, changes in plasma tnf concentration during each challenge exposure were quantitated by use of radioimmunoassay. Healthy Holstein bull calves with mean body weight of 90 kg were each given, in order, on different days, saline solution (5.0 ml, iv, day 1, n = 4), e (type 055:B5, 1.0 μg/kg of body weight iv, day 2, n = 4) and tnf (5.0 μg/kg iv, day 9, n = 3). Jugular venous blood samples, rectal temperature reading, and pcv were obtained at hourly intervals before (2 hours) and after challenge exposure. The pcv increased (P < 0.05) after e and tnf administrations for the first 5 hours, then returned to normal in calves given E, but decreased and remained low in calves given tnf through 24 hours. Plasma triglyceride and nonesterified free fatty acids concentrations were increased through 10 hours (P < 0.05) after e administration, whereas triglyceride and nonesterified free fatty acids concentrations were not significantly affected by tnf administration. Increase in blood glucose concentration at 1 hour after administration of e and tnf was followed by prolonged hypoglycemia that lasted through 6 hours. Changes in plasma insulin concentration paralleled the observed changes in glucose concentration, initially increased at 2 hours after e and tnf (P < 0.05) administrations, but then tended to decrease below control values thereafter. Plasma growth hormone and luteinizing hormone concentrations decreased after e and tnf administrations to almost nondetectable values through 4 hours after dosing, returning to normal values by 8 hours. The data indicate similarities in physiologic response of calves to e and tnf and suggest a role for acute production of tnf as a mediator of e responses.

Free access
in American Journal of Veterinary Research

Objective

To evaluate effectiveness of an allicin-based product in neonatal calves inoculated with Cryptosporidium parvum.

Design

Randomized controlled study.

Animals

43 neonatal calves.

Procedure

Calves were inoculated with 1.5 × l06 or 7.5 × 105 C parvum oocysts within 2 days after birth. Calves were given an allicin-based product once after inoculation or daily for 7 days after inoculation or were not treated. Calves that developed diarrhea were treated by administration of the product. Fecal consistency scores and weight gains were statistically evaluated.

Results

Mean daily weight gain and severity of diarrhea in calves 4 to 21 days old were unaffected by prophylactic use of the product. However, intensive prophylactic administration may have delayed onset of C parvum-induced diarrhea in calves inoculated with the lower dose of oocysts.

Clinical Implications

Administration of an allicin-based product did not alter duration of C parvum-induced diarrhea or enhance weight gain in neonatal calves. However, intensive prophylactic administration of an allicin-based product may delay onset of diarrhea in calves exposed to C parvum oocysts. (J Am Vet Med Assoc 1998;212:987–990)

Free access
in Journal of the American Veterinary Medical Association