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Exposure to endotoxin during estrus alters the timing of ovulation and hormonal concentrations in cows
Year:
2008
Source of publication :
Theriogenology
Authors :
Braw-Tal, Ruth
;
.
Jacoby, Shamay
;
.
Volume :
70
Co-Authors:
Lavon, Y., Department of Animal Science, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Leitner, G., National Mastitis Laboratory, The Veterinary Institute, Bet Dagan, 50250, Israel
Goshen, T., School of Veterinary Medicine, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Braw-Tal, R., Institute of Animal Science, Agricultural Research Organization, Bet Dagan, 50250, Israel
Jacoby, S., Institute of Animal Science, Agricultural Research Organization, Bet Dagan, 50250, Israel
Wolfenson, D., Department of Animal Science, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Facilitators :
From page:
956
To page:
967
(
Total pages:
12
)
Abstract:
The effect of intramammary (IMM) or intravenous (IV) administration of E. coli endotoxin (LPS), at the onset of estrus, at the time of ovulation was examined. Steroid and gonadotropin concentrations around ovulation were also determined. Lactating Holstein cows (n = 33) were assigned to saline-controls (n = 12) and treated with LPS-IV (0.5 μg/kg; n = 13) or LPS-IMM (10 μg; n = 8). Synchronized cows were observed continuously for estrus. LPS (or saline) was injected within 30 min from the onset of standing estrus, at peak estradiol concentrations. The typical rise of body temperature, somatic cell count, cortisol, and NAGase activity was noted. One-third of both LPS-IV- and LPS-IMM-treated cows were manifested by an extended estrus to ovulation (E-O) interval of around 75 h or did not ovulate, compared with about 30 h in the other 2/3 of LPS cows and all controls. Estradiol concentrations 24 h before and after LPS did not differ between groups. However, LPS-IV cows with extended intervals exhibited another estrus and an additional rise of estradiol followed by delayed ovulation. LPS-treated cows with a delayed E-O interval had low or delayed LH surge; two LPS-treated cows did not exhibit LH surge and did not ovulate. All control cows exhibited normal hormone levels. Delayed ovulation was associated with a delayed rise of luteal progesterone. The results indicated that exposing cows to endotoxin during estrus induced a decreased and delayed LH surge in one-third of the cows. This was associated with delayed ovulation, which reduces the chances of successful fertilization. © 2008 Elsevier Inc. All rights reserved.
Note:
Related Files :
Animal
Animals
Blood
cattle
cows
drug effect
Female
hormones
intradermal drug administration
intravenous drug administration
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More details
DOI :
10.1016/j.theriogenology.2008.05.058
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
29926
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:50
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Scientific Publication
Exposure to endotoxin during estrus alters the timing of ovulation and hormonal concentrations in cows
70
Lavon, Y., Department of Animal Science, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Leitner, G., National Mastitis Laboratory, The Veterinary Institute, Bet Dagan, 50250, Israel
Goshen, T., School of Veterinary Medicine, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Braw-Tal, R., Institute of Animal Science, Agricultural Research Organization, Bet Dagan, 50250, Israel
Jacoby, S., Institute of Animal Science, Agricultural Research Organization, Bet Dagan, 50250, Israel
Wolfenson, D., Department of Animal Science, The Faculty of Agriculture, The Hebrew University, Rehovot, 76100, Israel
Exposure to endotoxin during estrus alters the timing of ovulation and hormonal concentrations in cows
The effect of intramammary (IMM) or intravenous (IV) administration of E. coli endotoxin (LPS), at the onset of estrus, at the time of ovulation was examined. Steroid and gonadotropin concentrations around ovulation were also determined. Lactating Holstein cows (n = 33) were assigned to saline-controls (n = 12) and treated with LPS-IV (0.5 μg/kg; n = 13) or LPS-IMM (10 μg; n = 8). Synchronized cows were observed continuously for estrus. LPS (or saline) was injected within 30 min from the onset of standing estrus, at peak estradiol concentrations. The typical rise of body temperature, somatic cell count, cortisol, and NAGase activity was noted. One-third of both LPS-IV- and LPS-IMM-treated cows were manifested by an extended estrus to ovulation (E-O) interval of around 75 h or did not ovulate, compared with about 30 h in the other 2/3 of LPS cows and all controls. Estradiol concentrations 24 h before and after LPS did not differ between groups. However, LPS-IV cows with extended intervals exhibited another estrus and an additional rise of estradiol followed by delayed ovulation. LPS-treated cows with a delayed E-O interval had low or delayed LH surge; two LPS-treated cows did not exhibit LH surge and did not ovulate. All control cows exhibited normal hormone levels. Delayed ovulation was associated with a delayed rise of luteal progesterone. The results indicated that exposing cows to endotoxin during estrus induced a decreased and delayed LH surge in one-third of the cows. This was associated with delayed ovulation, which reduces the chances of successful fertilization. © 2008 Elsevier Inc. All rights reserved.
Scientific Publication
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