One of the issues that emerges from our study of human beings is that cross-feeding of newborn infants with dairy-based formula milk leads to the development of atopic illnesses within a population and that the atopy will spread from mother to offspring over repeated generations, as described from epidemiological studies, by Maureen Minchin (2016). The same applies to most mammal species and especially those predators that consume prey that may be of bovine origin.
There are so many consequences of the principles described above and they reach into so many areas, from the cost of pet health maintenance to the reintroduction of rare species to their former habitat. Creating the potential for a wide range of atopic symptoms in rare species living in the wild is, in the long run, likely to reduce their chance of survival as a species, rather than enhance it. Especially in the case of predatory mammals for whom the occasional prey may be related to the cattle group of ungulates. Captive-bred mammal species must be cleared of any chance of atopy before they can be returned to the wild. No captive mammals nurtured on formula milk as newborns should ever be returned to join a wild population because, from an immunological perspective, they are no longer wild. Many captive bred big cats are now seen to be in various stages of disablement through arthritis – a typical atopic symptom.
Just as there is a need for mothers to plan for successful breastfeeding, so zoos should take further steps for natural birth and nurture of newborn mammals and not take newborns directly from the mother animal to secure safety. Quite a few predators will kill their offspring if the environment they are in is too stressful to them. It is this environment that needs to change and not the source of sustenance for each newborn animal, if the health of the group is to be maintained. There also needs to be a back-audit of the nurture of every zoo mammal from birth, to ensure that breeding females are not already programmed to pass on the antibodies to foodstuffs that will ensure atopy in the following generations. In some cases the back-audit will need to extend back over more than one generation, especially where the lineage has been zoo bred for many years.