ISSN: 2474-9222
Authors: Ball RL*
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis, a contagious, chronic, and eventually fatal enteric disease of domestic and non-domestic ruminants. MAP is highly resistant to heat, disinfectants, and environmental agents, staying infective for a long time in the environment which makes biosecurity a challenge when trying to control this disease in domestic, zoo ruminants, and especially wild animals. The highest burden of MAP is in domestic ruminants, followed by zoo ruminant species, and then frees ranging wild ruminants. The overall physiology and pathophysiology of MAP when it occurs in all three ruminant groups is essentially identical, so environmental factors would appear to have dominant roles in explaining the differences in the prevalence among the three groups. Herd prevalence in a group of comingled managed zoo ruminants nyala (Tragelaphus angasii), impala (Aepyceros melampus) and Thomson’s gazelle (Gazella thomsonii) show a clear difference between the low prevalence of MAP in the Thomson’s gazelle compared to both he impala and nyala. When Thomson’s gazelle herd were later fed a high intake of concentrate rations in a similar fashion to the nyala and impala, the prevalence of MAP then started to approach these latter species. Feeding niches and nutrition, especially high concentrate, low fiber feeding, leads to a higher prevalence of MAP. Hypocalcemia or increased calcium demand parallels this trend in MAP prevalence amongst these three comingled species. The observation is that the more intensively managed any ruminant becomes, especially in terms of feeding, the higher the apparent prevalence of MAP. In this regards MAP infection can be more appropriately thought of as an anthropogenic condition. This perspective may allow for exploring other control measures focused on feeding practices and more specifically on calcium metabolism.
Keywords: Mycobacterium Avium Ss. Paratuberculosis; Zoo Ruminants; Calcium; Nutrition; Forages; Concentrates
