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Description:
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The equine breeding industry continues to be somewhat inefficient , even with existing technology . On average , foaling rates are low when compared with that of other livestock . One major contributor is the inability to accurately predict ovulation in mares , which ovulate before the end of estrus , leaving much variability in coordinating insemination . A more efficient , less invasive method that could replace or reduce the need for constant teasing and ultrasonography to evaluate follicular activity is needed . In both dairy cattle and women , a change in body temperature has been shown to occur immediately prior to ovulation . Research on horses has been limited , although one study reported no useable relationship between body temperature and ovulation in mares (Ammons , 1989 ) . The current study utilized thirty -eight mature cycling American Quarter Horse mares , and was conducted from March -August 2004 . Each mare was implanted in the nuchal ligament with a microchip that can be used for identification purposes , but is also capable of reporting body temperature . Once an ovulatory follicle ( >35mm ) was detected using ultrasonography and the mare was exhibiting signs of estrus , the mare's follicle size and temperature were recorded approximately every six hours until ovulation . Not only was the temperature collected using the microchips , but the corresponding rectal temperature was also recorded using a digital thermometer . A significant effect (p <0 .05 ) on body temperature was noted in relation to the presence or absence of an ovulatory follicle ( >35mm ) under different circumstances . When evaluating the rectal temperatures , no significant difference was found in temperature in relation to the presence or absence of a follicle . However , in the temperatures obtained using the microchip , temperature was higher (p <0 .05 ) with the presence of a follicle of greater than 35mm . This may be due to the extreme sensitivity of the microchip implant and its ability to more closely reflect minute changes in body temperature . |