Effect of bovine interferon-tau on body temperature and plasma progesterone concentrations in cyclic dairy cows.
We examined the effect of intramuscular injections of recombinant bovine interferon-tau on basal body temperature and plasma concentrations of progesterone in cows. Six mature, nonlactating Holstein cows were synchronized for estrus and assigned randomly to a replicated 3 x 3 Latin square design to receive 0, 1, or 5 mg of recombinant bovine interferon-tau intramuscularly on d 9, 12, or 15 of the estrous cycle. Rectal temperatures were measured, and blood was collected just prior to injection, at hourly intervals for 8 h, and at 10 and 12 h after injection. Treatment with 1 and 5 mg of recombinant bovine interferon-tau caused a rise in body temperature that peaked at 6 h (39.5 +/- .13 degrees C) and 4 h (40.3 +/- .13 degrees C), respectively. Analysis of homogeneity of regression for response curves indicated that 5 mg of recombinant bovine interferon-tau decreased plasma progesterone concentrations. This effect was not detected for the 1-mg dose of recombinant bovine interferon-tau. Intramuscular administration of 5 mg of recombinant bovine interferon-tau caused a hyperthermic response that was temporally associated with the decrease in plasma progesterone. Intramuscular administration of 1 mg of recombinant bovine interferon-tau caused a slight rise in temperature occurring 4 h later than that caused by 5 mg of recombinant bovine interferon-tau, and no decrease in plasma progesterone was detected. Recombinant bovine interferon-tau, administered at a 1-mg dose, warrants further study to determine whether it will alter survival rate of cattle embryos.
Meyer
M D
MD
Department of Dairy and Poultry Sciences, University of Florida, Gainesville 32611-0920, USA.
Hansen
P J
PJ
Thatcher
W W
WW
Drost
M
M
Roberts
R M
RM
D000818:Animals; D001831:Body Temperature; D002417:Cattle / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004971:Estrus; D005260:Female; D007273:Injections, Intramuscular; D007370:Interferon Type I / Q000008:administration & dosage / Q000494:pharmacology*; D011257:Pregnancy Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood*; D011994:Recombinant Proteins / Q000494:pharmacology; D012044:Regression Analysis
D007370:Interferon Type I; D011257:Pregnancy Proteins; D011994:Recombinant Proteins; C020947:interferon tau; D011374:Progesterone