Two experiments were carried out to study the role of gender category in evaluations of face distinctiveness. In Experiment 1, participants had to evaluate the distinctiveness and the femininity-masculinity of real or artificial composite faces. The composite faces were created by blending either faces of the same gender (sexed composite faces, approximating the sexed prototypes) or faces of bo...

Obtaining sexed sperm from previously frozen doses (reverse-sorted semen [RSS]) provides an important advantage because of the possibility of using the semen of bulls with desired genetic attributes that have died or have become infertile but from whom frozen semen is available. We report the efficiency of RSS on the pregnancy rate and birth rate of calves in a large-scale program using ovum pi...

Sex preselection is a subject that has held man’s attention for generations. The most effective way to achieve sex predetermination is to resolve X and Y chromosome bearing sperm populations. One of the most reliable methods of sorting spermatozoa is flow cyto-fluorimetric analysis, which is based on the difference in the DNA content of the X and Y sperm populations. The difference in the DNA c...

The objective of the study was to compare embryo development rates after transfer of oocytes collected 22 or 33 h after hCG injection into recipients inseminated within the uterus or the oviduct. Oocytes were collected at approximately 22 or 33 h after hCG injections and incubated for approximately 16 or 1.5 h, respectively, before transfer. Intrauterine inseminations using 1 x 10(9) progressiv...

Crossbreeding is a popular tool for genetic improvement of pigs, beef cattle, and other livestock species, but its use in US dairy cattle has been limited for several reasons. The primary reason is the advantage of Holstein cows in milk volume, coupled with a milk pricing system that still tends to reward quantity, rather than quality, in many regions of the country (i.e., through volume premiu...