The whole semen sample is composed of multiple secretions from various parts of the male reproductive system. As each part contributes a different portion of the greater whole, in a specific sequence, it, therefore, makes sense that the distribution of sperm cells throughout the ejaculatory process is uneven.
The split-ejaculate method describes the collection of a semen sample in two halves, into two different containers. These two fractions, which have vastly different quantities of their components, will usually be mixed together, diluting one another. However, the first half of the semen sample will usually have a higher concentration of sperm cells, with superior motility. Therefore, the split ejaculate method allows the collection of a higher quality sample for artificial insemination.
