US Patent Number
A method and composition are provided for extending the gestation period of a sow so as to increase the live birth and survival rates of a swine litter without adversely affecting the sow. The method includes the step of administering an effective dosage of estrogen to the sow 21/2-7 days prior to the end of the expected gestation period for the sow. The composition administered includes from 0.5-10 mg of an estrogen selected from a group consisting of estradiol benzoate, estradiol valerate, estrone, estradiol 17β and effective mixtures thereof. The composition is adapted for administration parenterally by including a carrier such as corn oil. A method is also provided for synchronizing farrowing in a herd of swine bred following synchronized weaning so as to shorten the target period during which all the sows of the herd begin farrowing. This method involves the administration of a farrowing delaying composition including estrogen as an active ingredient in combination with the administration of an effective dosage of a farrowing inducing composition that may include a prostaglandin as the active ingredient.
University of Kentucky Research Foundation, Lexington, Ky.
Edgerton, Lee A. and Eckerle, Bruce T., "Method and Composition for Safely Delaying Parturition and Synchronizing Farrowing in Swine" (1989). Animal and Food Sciences Faculty Patents. Paper 9.