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Title:Relationship Between Physical Activity, Stage of Estrous Cycle, Sexual Behavior and Plasma Luteinizing Hormone in Dairy Cattle (Electronic Pedometers)
Author(s):Vasquez, Luis Alberto
Department / Program:Veterinary Medical Science
Discipline:Veterinary Medical Science
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Biology, Veterinary Science
Abstract:Detection of estrus remains as one of the major factors affecting reproductive performance in dairy cattle. Use of electronic equipment such as programmable electronic pedometers may assist detecting changes in physical activity that occur during the day of estrus in cattle.
A series of 3 experiments was performed to evaluate hourly physical activity during the estrous cycle cows and heifers, to compare the activity pattern during natural and Prostaglandin F-2alpha induced estrus and to study the relationship between the increase in physical activity, sexual behavior and preovulatory LH surge. One electronic pedometer was attached to the right rear leg of each animal to monitor the physical activity pattern during a breeding period. Ovarian function and estrous cycles were monitored by plasma progesterone determinations and sexual behavior.
The 24-hour activity pattern showed a 2-fold increase during the day of estrus. Diurnal cycles were established by 6-hour activity intervals. Pedometer counts during the night were significantly lower than pedometer counts during the day. Animals, days, quarters of day and their interactions were identified as significant sources of variation on pedometer counts. There were no differences in the activity pattern during natural or Prostaglandin F-2alpha induced estrus. Time of day when estrus was first observed appeared to affect the duration of the increase in activity during estrus. The increase in activity was longer in duration (16 vs 10 h) among the animals showing estrus in the morning than among these showing estrus during the afternoon.
Calculation of activity rates between the same 12-hour interval of 3 consecutive days, every 6 hours, was highly efficient (> 80%) in detecting 2- or 3-fold increases in activity during estrus. Short intervals (6- or 3-hours) were less accurate than the 12-hour interval to calculate activity rates. Periodicity of the activity cycles showed a shift from low-frequency cycles (24-hours/cycle) during diestrus to high-frequency cycles (4-, 8-, 12-hours/cycle) during the estrous period. A relationship between the increase in activity, sexual behavior and preovulatory LH surge was evident during the period of standing estrus in heifers.
These results demonstrated a significant increase in physical activity during the day of estrus in dairy cattle. There was an association between physical activity, sexual behavior and hormonal changes during estrus. Programmable electronic pedometers can be used as efficient aids for detection of estrus in dairy cattle.
Issue Date:1985
Description:166 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
Other Identifier(s):(UMI)AAI8511686
Date Available in IDEALS:2014-12-16
Date Deposited:1985

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