Breed, parity, and cycle season effects on life-timereproduction in bitches: a retrospective study

Abstract

IntroductionBitches are monoestrous, spontaneous ovulatory and traditionally nonseasonal mammalians, except for some breeds such as Basenji and Chow-Chow (1). The estrous cycle of the bitch is considerably longer than that of other domestic species and the estrous period is followed by a longer interestrous interval (diestrus and anestrus) (2). The interval is highly variable (2-10 months) among the breeds (3,4). Various factors that affect the interestrous period and pregnancy duration, such as breed, age, parity, and litter size have been described in previous studies (3,5,6).Although bitches are considered nonseasonal, the seasonal effect on the reproductive parameters are still contradictory. Studies confirming (1,7,8) and denying (3,9-11) seasonal effects on bitch reproduction are available. To our knowledge, this was the first comprehensive retrospective study in Turkey investigating reproduction in bitches to reveal: 1) the distribution of whelping among breeds; 2) the breed and parity effect on pregnancy rates; 3) the breed, parity, and estrus onset season effects on the cycle interval, the proestrus, and estrus length; and 4) the breed and parity effects on the pregnancy duration and litter size.

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

“…The results of our study are in line with Eilts et al (2005), Mir et al (2011), andPolat et al (2015) who found a negative relationship between litter size and pregnancy length in large breeds as well. Our study documented for the first time the negative effect of gestation length on the number of live puppies born.…”

“…A combination of these (Mandigers et al 1994) stand behind the final numbers of puppies registered in kennel clubs, and parity of the bitch can be classified among the major factors (Borge et al 2011). Studies evaluating the effect of parity on litter size in different breeds revealed a significant influence of parity when only parity (not parity and breed) was incorporated to a statistical model (Borge et al 2011;Polat et al 2015). In Drever bitches kept as a colony in a private kennel, the litter size at the time of birth increased slightly from the 1 st to the 3 rd parity (Gavrilovic et al 2008).…”

Study the Reproductive Pattern of Different Breeds Bitches in Iraq by estimation of Kisspeptin and detection ovulation time.

“…According to breeds of bitches the levels of kisspeptin were (248.74 ± 11.53) pg/ml, (251.3 ± 10.76) pg/ml, (246.19 ± 10.1) pg/ml, (276.5216 ± 16) pg/ ml, and (241.6455 ± 6.9) pg/ml in German Shepherd, Belgian Malinois, Husky, Terrier and other breeds respectivelywith no significant. This result may be due the most breeds (German Shepherd, Belgian Malinois, Husky, Terrier) examined in this study considered as a non-seasonal pattern for estrous cycle (31)(32)(33)(34)(35).…”

A retrospective study of female reproductive parameters in the Kunming dog

“…Recently, Polat et al . () reported that each additional puppy was associated with a 0.24‐day decrease in pregnancy duration. However, this association has not been confirmed in other studies (Linde‐Forsberg & Forsberg ; Kutzler et al .…”