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Updated: Aug 8, 2026
06:01
Cortisol Extraction from Sturgeon Fin and Jawbone Matrices
Published on: September 10, 2019
Relationship between LH and cortisol in acutely stressed beef cows
1Roman L. Hruska U.S. Meat Animal Research Center U.S. Department of Agriculture Agricultural Research Service, Clay Center, NE 68933 USA.
Theriogenology
|September 1, 1984
Summary
Animal handling stress significantly impacts luteinizing hormone (LH) secretion in cows. Acclimation to procedures reduces cortisol and enhances LH release, highlighting stress management importance in reproductive studies.
Area of Science:
- Veterinary Science
- Reproductive Endocrinology
- Animal Physiology
Background:
- Handling stress is a significant factor affecting physiological responses in livestock.
- Understanding the impact of stress on reproductive hormones like luteinizing hormone (LH) is crucial for animal welfare and productivity.
Purpose of the Study:
- To evaluate the influence of handling stress on tonic LH secretion in ovariectomized Hereford cows.
- To determine the relationship between cortisol levels, stress adaptation, and LH secretion patterns.
Main Methods:
- Eight ovariectomized Hereford cows were divided into acclimated and unacclimated groups.
- Blood samples were collected every 10 minutes for 4 hours to measure cortisol, LH, and progesterone.
- Cortisol and LH concentrations were analyzed for correlations and effects on LH secretion.
Main Results:
- Acclimated cows exhibited lower mean cortisol (5.7 ng/ml) and higher mean LH (8.1 ng/ml) compared to unacclimated cows (66.1 ng/ml and 4.1 ng/ml, respectively).
- Plasma cortisol and LH concentrations were negatively correlated (r = -0.83).
- Intensive stress causing 10- to 20-fold cortisol increases suppressed tonic LH secretion, particularly pulsatile releases.
Conclusions:
- The impact of stress on gonadotropin secretion is dependent on the magnitude of the adrenal response and the animal's adaptation to stress.
- Minimizing and monitoring animal stress is essential when investigating LH secretion and reproductive function in cattle.
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