Providing ‘get-away bunks’ and other enrichments to primiparous adult female mink improves their reproductive productivity

Effects of environmental enrichment and stereotypic behavior on maternal behavior and infant viability in a model carnivore, the American mink (Neovison vison)

“…Infant mortality was calculated as the percentage of dead kits per litter at PND1, and at PND20 as the difference in living kits between PND20 and PND1. In addition, to compare results to those of Buob et al, (which reported IM at 6 weeks of age), we also report already published results (Díez‐León et al, ) on LS at PND50. Litter sex ratio: sex ratios were calculated as the percentage of males to total offspring per litter at PND1 (both including stillbirths and only living kits) and PND20. This was recorded to control for possible sex biases in LG, since males can attract more (e.g.…”

“…In conclusion, our experiment needs replicating addressing the methodological issues stated above. However, previous enrichment effects on mink infant mortality (Buob et al, ), and our hints that nest‐building and infant growth could both be improved by enrichment, suggest that this is a worthwhile enterprise. Furthermore, research in primates and rodents shows that maternal behavior not only influences offspring survival, but also has profound effects on offspring adult health, stress reactivity and reproduction (reviewed in Meaney, ; Cameron et al, ; Beery and Francis, ).…”

“…We were thus unable to replicate the previous large scale study (Buob et al, ), in which 164 farmed female mink given shelves during lactation weaned more kits. Their result could have been a Type I error: two other mink studies found no such effects (Díez‐León et al, ; Meagher et al, ).…”

“…For example, red panda infant mortality is higher in North American zoos than European or Australian zoos (40% vs. respectively 24% and 11%, Glatston, ), as is tiger Panthera tigris infant mortality in inexperienced versus experienced zoos (Saunders et al, ), and cheetah Acinonyx jubatus infant mortality in zoos compared to in situ breeding facilities (36.4% vs. 28.7%, Marker and O'Brien, ; Bertschinger et al, ). Third, adding a structure to a bare cage—an elevated resting shelf for nursing mothers—can reduce infant mortality in American mink Neovison vison on fur farms (Buob et al, ). Indeed such 'environmental enrichments' have long been suggested as potentially beneficial for reproduction (Carlstead and Shepherdson, ).…”

Play in juvenile mink: litter effects, stability over time, and motivational heterogeneity

“…In the wild, they typically disperse from the natal territory between 11 and 16 weeks of age (Dunstone, ; Gerell, ; Jonasen, ). In captivity, North American farms typically separate mothers from litters and subsequently move kits into pair‐housing between 6 and 10 weeks of age (Buob et al, ; National Farm Animal Care Council, ). Social play is rare until 5.5 weeks, but rises in frequency over the following weeks and peaks during the summer juvenile phase (Brink & Jeppesen, ; Jonasen, ).…”