Factors affecting reproductive efficiency in German Shepherd bitches producing litters for Police of the Czech Republic

The present study on German Shepherd bitches bred in the same environment of a private kennel and producing offspring for working purposes aimed to ascertain if any of the parameters: litter size, number of live puppies, stillbirth and mortality of puppies is determined by the month of whelping, parity, number of whelpings for one bitch over the course of one year, pregnancy length or bitch age at the time of whelping. Reproductive records of 73 bitches of German Shepherd breed (GSB) documented since 2001 till 2013 were processed. A total of 298 whelpings resulted in 2075 puppies; mortality of puppies was evaluated within the first 3 weeks of life. A significant seasonal influence on litter size and number of live born puppies, but not on stillbirth or mortality, was found. The parity of GSB significantly influenced litter size, live born puppies, and the incidence of stillbirths. The number of whelpings in one bitch over the course of one year significantly influenced litter size, while puppy losses were the same when bitches were bred once or twice a year. Litter size and number of live born puppies had a significant negative effect on pregnancy length. Furthermore, the number of stillbirths significantly increased when pregnancy was prolonged. Bitch age did not influence litter size, number of live born puppies and stillbirths, however it significantly affected mortality.