Artificial insemination of heifers with cooled, unfrozen sexed semen

Sperm Sexing in Animals

“…AI with flow sorted rabbit sperm resulted in fewer fetuses between days 7 and 14 of gestation than non-sorted sperm (Mcnutt and Johnson, 1996). However, Seidel et al (1998) found no excess embryonic loss between 1 and 2 months of gestation in heifers inseminated with sorted sperm.…”

Sex‐Sorting Mammalian Sperm: Concept to Application in Animals

“…Sufficient X-selected sperm were prepared so that 35 heifers could be inseminated with 3 ϫ 10 5 unfrozen sperm/dose. Forty-two percent of the heifers inseminated with the sexed sperm became pregnant compared with a 54% pregnancy rate for controls inseminated with 3 ϫ 10 5 motile unfrozen sperm (Seidel et al, 1998). Eighteen of the 19 calves born to X-sorted sperm were females (Seidel et al, 1998).…”

Sexing mammalian spermatozoa and embryos – state of the art

“…Some of these also have improved electronics; a few microseconds difference in accomplishing each of the various steps of signal detection and processing can make a great difference in performance of such instruments. We have been using one such instrument routinely to obtain over 600 live spermatozoa s-1of each sex (Seidel et al, 1998). Another improvement is in nozzle design (Johnson et al, 1998).…”

“…To what extent such damage can be decreased by improved techniques or overcome by compensatory numbers of spermatozoa or other means is unknown. However, it is clear that pregnancy rates are not compromised greatly with sorted spermatozoa, even though they have sustained some damage (Seidel et al, 1998).…”

“…The second study (Seidel et al, 1998) was logistically less demanding. A high performance flow cytometer and cell sorter provided 500-600 live spermatozoa s-I of each sex, and the cattle were only 200 km distant from the instrument.…”