Rutberg Allen T, Grams Kayla A
Cummings School of Veterinary Medicine at Tufts University, 200 Westboro Road, North Grafton, MA 01536, USA.
Science and Conservation Center, 2100 South Shiloh Road, Billings, MT 59106, USA.
Animals (Basel). 2024 Dec 9;14(23):3550. doi: 10.3390/ani14233550.
Wildlife managers and the public have expressed considerable interest in the use of contraception to help manage the populations of wild horses and burros ( and ). Field testing has shown that two preparations of the porcine zona pellucida (PZP) vaccine, a simple emulsion (ZonaStat-H) and PZP-22 (which supplements ZonaStat-H with a controlled-release component) effectively prevent pregnancy in individual mares and can substantially reduce population foaling rates. To determine whether some PZP preparations might have secondary effects that harm treated mares or their foals, we examined the effects of PZP-22 vaccinations and the follow-up boosters of either PZP-22 or ZonaStat-H on adult female body condition, foaling season, and foal mortality in two wild horse herds in the western USA, Cedar Mountains Herd Management Area, Utah (CM; 2008-2015), and Sand Wash Basin Herd Management Area, Colorado (SWB; 2008-2014). At both sites in every study year, summer body condition scores improved faster in mares without foals than mares with foals ( < 0.001; CM, = 234; SWB, = 172), but PZP treatments did not affect mare body condition apart from their contraceptive effects. Births to mares treated with PZP within the previous three years were delayed and spread out over the foaling season, but foal mortality rates through the first and second year were low, unrelated to date of birth, and virtually identical for the foals of PZP-treated and untreated mothers (all comparisons n.s.; CM, = 775, SWB, = 640). Thus, in these two populations, we found no evidence that changes in reproductive timing associated with PZP treatments were harmful to either mares or foals.
野生动物管理者和公众对使用避孕措施来帮助管理野马和野驴种群表现出了浓厚兴趣。野外测试表明，猪透明带（PZP）疫苗的两种制剂，一种简单乳剂（ZonaStat-H）和PZP-22（它通过一个控释成分补充ZonaStat-H）能有效防止母马怀孕，并能大幅降低种群产驹率。为了确定某些PZP制剂是否可能产生危害接受治疗母马或其幼驹的副作用，我们在美国西部的两个野马种群，犹他州锡达山种群管理区（CM；2008 - 2015年）和科罗拉多州桑德沃什盆地种群管理区（SWB；2008 - 2014年），研究了PZP-22疫苗接种以及后续PZP-22或ZonaStat-H加强针剂对成年母马身体状况、产驹季节和幼驹死亡率的影响。在每个研究年份的两个地点，没有幼驹的母马夏季身体状况评分比有幼驹的母马改善得更快（<0.001；CM， = 234；SWB， = 172），但PZP处理除了其避孕效果外，并未影响母马身体状况。在过去三年接受PZP治疗的母马所产幼驹的出生时间延迟且在产驹季节分散，但第一年和第二年的幼驹死亡率较低，与出生时间无关，并且接受PZP治疗和未接受治疗的母马所产幼驹的死亡率几乎相同（所有比较均无显著差异；CM， = 775，SWB， = 640）。因此，在这两个种群中，我们没有发现证据表明与PZP处理相关的繁殖时间变化对母马或幼驹有害。
