
TY  - JOUR
A1  - Schenk, J. 
A1  - Crichton, E. 
T1  - 351 INSEMINATION OF HOLSTEIN HEIFERS WITH SEXED SPERM PROCESSED WITH OR WITHOUT EGG YOLK IN THE GLYCEROL-CONTAINING FREEZING MEDIUM
JF  - Reproduction, Fertility and Development
JO  - Reprod. Fertil. Dev.
Y1  - 2005
VL  - 18
IS  - 2
SP  - 282
EP  - 283
KW  - 
UR  - https://doi.org/10.1071/RDV18N2AB351 
N2  - Preparation of media for use in processing sorted sperm is laborious and expensive. The objective was to determine whether pregnancy rates in heifers following AI of frozen/thawed X chromosome-bearing sperm were equivalent for sperm processed for cryopreservation using glycerol-containing medium with or without egg yolk. X chromosome-bearing sperm from each of two Holstein bulls were isolated on the basis of DNA content using a flow cytometer. Sorted sperm were collected in 50-mL plastic tubes containing 2-mL of 20% egg yolk-TRIS extender without glycerol until each tube contained 12.4 mL and approximately 12 million sperm. Sorted sperm were cooled (5°C) over 90 min before the addition of 12% glycerol-containing TIS medium with or without 20% egg yolk, as two equal volumes (6.5 mL) at 15-min intervals. Tubes containing 25 mL were centrifuged at 850g for 20 min (5°C). After the supernatant was removed, sperm pellets within treatments and bulls were pooled. Sperm concentration was adjusted to 10 × 106/mL with medium containing 6% glycerol and 20% egg yolk-TRIS. Sorted sperm were packaged and frozen in 0.25 mL-coded straws on freezing racks in LN2 vapor. Straws from each bull-treatment combination were equally packaged in goblets to assure random use. Post-thaw sperm progressive motility, determined with time-lapse photography ('track motility'), was 44% for non-egg yolk and 43% for 20% egg yolk-glycerol-containing media. Nonsynchronized Holstein heifers (n = 119) were inseminated 4, 12, or 24 h after observed standing estrus. Sperm were deposited into the uterine body anterior to the internal cervical os. Approximately 1 month after insemination, pregnancy was determined using ultrasound. Data were subjected to ANOVA. The pregnancy rate and 95% confidence interval for sorted sperm processed with non-egg yolk-glycerol-containing medium was 56% (49-73; n = 59), and 55% (38-62; n = 60) for the 20% egg yolk-glycerol-containing medium (P > 0.1). Bull or inseminator effects on pregnancy rates were not significant (P > 0.01). Pregnancy rates as a function of time of insemination at 4, 12, or 24 h relative to observed estrus were 62% n = 65; 48% n = 48; and 50% n = 6, respectively (P > 0.1). Even though the scope of the field trial was limited, omission of egg yolk from the glycerol-containing medium did not adversely affect pregnancy rates. Preparation of non-egg yolk-glycerol-containing medium greatly reduces associated time, labor, and expense. This study also resulted in quite acceptable pregnancy rates with insemination doses of 2 × 106 total sorted frozen/thawed sperm. 
ER  -

