Pregnancy status is a key parameter used to assess reproductive performance of a species as it represents a starting point for measuring vital rates. Vital rates allow managers to determine trends in populations such as neonate survival and recruitment; two important factors in ungulate population growth rates. Techniques to determine pregnancy have generally involved capture and restraint of the animal to obtain blood samples for determining serum hormone levels. Non-invasive pregnancy assessment, via feces, eliminates any hazards between handler and animal, as well as removes handling-induced physiological biases. Using noninvasive fecal sampling, we conducted hormone validations, investigated pregnancy rates, and determined hormone degradation rates across five subpopulations of pronghorn (Antilocapra americana) in Idaho. Samples were collected during April-May of 2018 and 2019 from adult pronghorn of known sex and age class. Metabolites of testosterone, cortisol, 17β-estradiol, and progesterone were measured in fecal samples, and concentrations of estradiol and progesterone were examined for pregnancy determination. Average fecal progesterone metabolite (FPM) levels of pregnant females were more than double compared to levels of nonpregnant females. Fecal estrogen metabolite (FEM) levels did not differ during concurrent sampling. The largest difference in FPM levels between pregnant and nonpregnant females began on 28 April. Pregnancy determination sampling showed average FPM levels for all five subpopulations were significantly different than the nonpregnant female validation group. Nonetheless, pregnancy rates for some subpopulations lacked conclusive estimates due to early fecal sampling. Fecal glucocorticoid metabolites (FGM) levels significantly differed between pregnant females and male pronghorn, but did not differ from nonpregnant females. Degradation rates of FPM and FGM differed across days, with values for FPM from Day 1 being significantly different from all subsequent days, and after Day 9 for FGM, demonstrating the requirement of fresh samples to accurately measure hormone concentrations. We concluded that a noninvasive method to diagnosis pregnancy is possible in pronghorn via progesterone metabolites if fresh samples are collected during late gestation.

妊娠状态是用于评估物种繁殖性能的关键参数，因为它代表了测量生命速率的起点。重要率允许管理人员确定人口趋势，例如新生儿存活率和招募情况；有蹄类动物种群增长率的两个重要因素。确定怀孕的技术通常涉及捕获和约束动物以获得用于确定血清激素水平的血样。通过粪便进行的非侵入性妊娠评估消除了处理者和动物之间的任何危害，并消除了处理引起的生理偏差。使用无创粪便取样，我们进行了激素验证，调查了妊娠率，并确定了叉角羚 ( Antilocapra americana ) 五个亚群的激素降解率) 在爱达荷州。样本是在 2018 年 4 月至 2019 年 4 月至 2019 年期间从已知性别和年龄等级的成年叉角羚中收集的。在粪便样本中测量睾酮、皮质醇、17β-雌二醇和孕酮的代谢物，并检查雌二醇和孕酮的浓度以确定妊娠。与未怀孕女性相比，怀孕女性的平均粪便孕酮代谢物 (FPM) 水平高出一倍以上。粪便雌激素代谢物 (FEM) 水平在同时采样期间没有差异。怀孕和未怀孕女性之间 FPM 水平的最大差异始于 4 月 28 日。妊娠测定抽样显示所有五个亚群的平均 FPM 水平与未怀孕女性验证组显着不同。尽管如此，由于早期粪便取样，一些亚群的妊娠率缺乏确凿的估计。妊娠雌性和雄性叉角羚的粪便糖皮质激素代谢物 (FGM) 水平存在显着差异，但与非妊娠雌性无差异。FPM 和 FGM 的降解率因天而异，第 1 天的 FPM 值与随后的所有日子显着不同，第 9 天后 FGM 的值显着不同，这表明需要新鲜样品才能准确测量激素浓度。我们得出的结论是，如果在妊娠晚期采集新鲜样本，则可以通过孕酮代谢物在叉角羚中采用无创方法诊断妊娠。但与未怀孕的女性没有区别。FPM 和 FGM 的降解率因天而异，第 1 天的 FPM 值与随后的所有天显着不同，第 9 天后 FGM 的值显着不同，这表明需要新鲜样品才能准确测量激素浓度。我们得出的结论是，如果在妊娠晚期采集新鲜样本，则可以通过孕酮代谢物在叉角羚中采用无创方法诊断妊娠。但与未怀孕的女性没有区别。FPM 和 FGM 的降解率因天而异，第 1 天的 FPM 值与随后的所有日子显着不同，第 9 天后 FGM 的值显着不同，这表明需要新鲜样品才能准确测量激素浓度。我们得出的结论是，如果在妊娠晚期采集新鲜样本，则可以通过孕酮代谢物在叉角羚中采用无创方法诊断妊娠。