State-of-the-art of the superstimulatory treatments utilized in bovine embryo transfer protocols and future perspectives for new improvements

Abstract

In the present article superstimulatory treatments based upon a protocol coined P-36,in which the time of ovulation is controlled by a progesterone source and exogenousadministration of LH, allowing the use of fixed-time artificial insemination (FTAI) inzebu (Bos indicus) and European breeds (Bos taurus), are briefly reviewed. Moreover,important recurrent topics such as the ideal semen concentration for fixed-time artificialinsemination (FTAI) of superstimulated donors, improvement of fertilization rate inembryo donors, and criteria to consider a donor refractory to superstimulatory treatments,were addressed. The discussion about the current obstacles for a wider use of multipleovulation and embryo transfer (MOET), in both dairy and beef cattle, may contribute tofuture research related to this topic. © 2009 Nova Science Publishers, Inc. All rights reserved.