title: Fecal progestin concentrations as an indicator of reproductive success in American Mink.
abstract: Efforts to increase mink reproductive success (live births and litter sizes) can be partly assessed by measurement of blood progesterone levels. However, the stress of blood sampling increases the incidence of failed matings, aborted fetuses and death of the dam. We have therefore non-invasively measured fecal progesterone metabolite (progestin) concentrations during the reproductive cycle of mink. We tested the hypothesis that fecal progestin concentrations during the window of implantation (late March-early April) will, (1): be higher for whelping than non-whelping mink, and (2): be higher for mink mated multiple times, compared to single matings. Mink were mated once (March 3), twice (March 3 and 10) or three times (March 3, 10 and 11) and fecal progestin concentrations determined from March 1 to April 30. The percent mink in each group giving birth to live offspring was 42.8%, 80.8% and 92.3% for mink mated once, twice or three times, respectively (P<0.05). Litter sizes did not differ among mink mated once (5.22±0.55), twice (6.29±0.35) or three times (6.08±0.32; P>0.05). Mean fecal progestin concentrations from mating to diapause (March 19) did not differ between mink that whelped or not, nor in response to the number of times mated. However, mean fecal progestin concentrations for mink that whelped were higher on March 25 (peri-implantation) than March 19 after being mated once (51.96±2.96 vs 23.53±1.89nM/g dry wt; P<0.05), twice (66.00±1.60 vs 25.57±1.28nM/g dry wt; P<0.05) or three times (66.48±1.42/g vs 19.16±1.09nM/g dry wt; P<0.05). During implantation (April 5), mean fecal progestin concentrations for mink that whelped after being mated once (146.60±10.02nM/g dry wt), twice (162.10±5.64nM/g dry wt) or three times (188.50±3.92nM/g dry wt) were significantly higher than for those that failed to whelp; 119.30±8.87nM/g dry wt, 77.84±5.86nM/g dry wt. and 118.9±6.55nM/g dry wt., respectively (P<0.05). Our findings suggest that measurement of fecal progestin concentrations during blastocyst reactivation and implantation may be a useful indicator of successful pregnancies in mink.
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Xinyan
authors.initials: X
authors.lastname: Cao
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wei
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Xue
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Weigang
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Shiyong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Diao
authors.affiliation: Idaho State University, Department of Biological Sciences, Pocatello, 83209, USA. Electronic address: rosewill@isu.edu.
authors.forename: Jack
authors.initials: J
authors.lastname: Rose
authors.affiliation: Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Jilin, 130112, PR China; State Key Laboratory for Molecular Biology of Special Economic Animal and Plant Science, Chinese Academy of Agricultural Sciences, Jilin, PR China. Electronic address: xubaozeng@hotmail.com.
authors.forename: Baozeng
authors.initials: B
authors.lastname: Xu
mesh_terms: D000818:Animals; D005243:Feces / Q000737:chemistry*; D005260:Female; D008907:Mink / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011372:Progestins / Q000737:chemistry / Q000502:physiology*
chemical_list: D011372:Progestins
keywords: Diapause; Fecal; Implantation; Mink; Progesterone; Progestin; Reproductive success