title: Influence of parity and litter size on gestation length in beagle dogs.
abstract: This study was conducted to investigate the effects of parity and litter size on gestation length in beagle bitches. The mean duration of the initial elevation (>2 ng/mL) in progesterone concentrations after the onset of proestrus was shorter (P < 0.05) in bitches without (nulliparous) whelping experience than in bitches with (multiparous) whelping experience (6.9 d versus 8.0 d). When calculated as the interval between the day of initial elevation in progesterone concentrations and the day of whelping, the gestation length in the nulliparous bitches was noted to be similar to that in the multiparous bitches (64.3 d versus 64.2 d). No significant correlation between gestation length and litter size was observed in any of the bitches. Our results indicate that the gestation length in beagle bitches is not affected by parity or litter size.
authors.affiliation: Laboratory of Animal Reproduction, The United Graduate School of Veterinary Sciences, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Seki
authors.forename: Norio
authors.initials: N
authors.lastname: Watanabe
authors.forename: Kenyo
authors.initials: K
authors.lastname: Ishii
authors.forename: Yoh-ichi
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Takehiro
authors.initials: T
authors.lastname: Aihara
authors.forename: Shuji
authors.initials: S
authors.lastname: Takeiri
authors.forename: Takeshige
authors.initials: T
authors.lastname: Otoi
mesh_terms: D000818:Animals; D004285:Dogs / Q000502:physiology*; D005260:Female; D008098:Litter Size; D010298:Parity; D011247:Pregnancy / Q000502:physiology*; D011359:Proestrus; D011374:Progesterone / Q000097:blood; D013997:Time Factors
chemical_list: D011374:Progesterone