Abstract: Selection and cloning methods are disclosed that are effective for the selective multiplication of desired animals, for instance livestock animals. These methods can be used to expand populations of animals, and are particularly useful for duplicating animals selected based on traits that are measured after the animal is deceased. Certain embodiments include techniques useful for selecting a desirable bovine animal (e.g., a desirable steer) based at least in part on a measurable carcass trait. Also described are specific cloning techniques that involve repetitive (for instance, two) cycles of cloning, such as nuclear transfer cloning. In specific embodiments, a two-step cloning system is described, in which the nuclear donor of the first cloning cycle is an adult fibroblast cell and the nuclear donor of the second cloning cycle is a fetal fibroblast harvested from a fetus that arose from the first cloning cycle.

Abstract: Provided herein are methods of managing embryo transfer programs, for instance bovine embryo transfer programs. Examples of such methods are referred to as “bred recipient transfer” programs, in which embryos (e.g., clonal embryos) are transferred to recipients that have been impregnated. Also provided are methods of enhancing survival of clonal embryos, in which the clonal embryos are transferred to bred recipients, and methods of increasing delivery success rates for cloned animals. Methods of serial transfer of embryos to a recipient, when that recipient returns to heat after an unsuccessful transfer, are provided. Finally, specific methods are provided for cloning male mammals, using diploid differentiated cells taken from a semen sample.