Fertility in bitches artificially inseminated with extended, chilled semen

Sixteen bitches were artificially inseminated with either fresh, 24 h-chill ed or 48 h-chilled extended semen over 38 estrous cycles. A commercial syst em for extending, chilling and transporting semen commonly used in the equi ne industry was used. Pregnancy rates and litter sizes of the bitches insem inated with extended, chilled semen (19/20, 95%; litter size = 7.1) were no t significantly different from those observed in bitches inseminated with f resh semen (17/18, 94%; litter size = 7.2; P greater than or equal to 0.89) . These results show that a commercial system for extending, chilling and t ransporting equine semen is an attractive and efficient method of shipping canine extended chilled semen. (C) 1999 by Elsevier Science Inc.