Increased iron absorption in lemurs: Quantitative screening and assessment of dietary prevention

Abstract

Iron storage disease (ISD) in lemurs has been reported since as early as the 1960s, and in the 1980s was demonstrated to be a consistent finding in postmortem investigations of captive lemurs. Since then this disease has consistently been diagnosed at the point of necropsy. In the current study we describe a preclinical screening procedure, as well as the quantified preventive effects of dietary intervention upon iron absorption. Twenty-three individual lemurs of four species were initially tested with the transferrin saturation test (%TS); 21 of these animals were on conventional zoo diets, and two were fed a specific diabetic diet. Initially, 20 of 21 lemurs on conventional zoo diets were demonstrated to have %TS levels above the normal range for humans; 17 of these lemurs were in the category (for humans) of excessive iron absorption. A dietary change aimed at reducing dietary iron and vitamin C levels and increasing the levels of iron-chelating tannins and/or phytates was instigated. After the animals were retested, a matched-pair comparison of %TS values before and after the diet change revealed significantly (P=0.038, n=7) lower %TS values after the diet change. All species averages were in the human hyperabsorption range on conventional zoo diets (n=21). No species averages were in that range after the dietary change (n=18). The results indicate that further investigations into the use of %TS testing in lemur husbandry, and specific preventive dietary measures, should be conducted.

The Pathology of Comparative Animal Models of Human Haemochromatosis

“…phytates and tannins), which may inhibit increased iron absorption in free-ranging individuals. High tannin levels have been reported in the natural diet of many lemur species, (Spelman et al, 1989;Wood et al, 2003).…”

The role of condensed tannins in ruminant animal production: advances, limitations and future directions

“…Tannic acid, a hydrolisable tannin, has been shown to reduce Fe availability in weanling pig diets (Lee et al, 2010). Condensed tannins have been used effectively to inhibit iron absorption and mitigate iron overload disorder in multiple exotic species (Wood et al, 2003;Lavin et al, 2010;Lavin, 2012). A final consideration is the contribution of CTcontaining ingredients to diets.…”

Update on Iron Overload in Zoologic Species

“…52 Equids (domestic horses, donkeys, and Persian onagers) are reported to develop hepatic hemosiderosis and occasionally hemochromatosis because of dietary iron overload. 14,25,55,63,70,71,72 In initial reports, the prevalence of ISD was 69% to 100% in zoo-housed lemurs, and ISD was considered a serious medical issue, especially in ruffed lemurs (Varieca sp.) 47 Marked variation was also noted in SI and %TS in banked serum from a variety of primate species from European zoos; %TS suggestive of ISD (>45%) was found in lemurs, common marmosets, and colobus.…”

“…10,40,60,72 Hidden sources of extra iron include other minerals such as dicalcium phosphate and drinking water. Iron concentrations as low as 30 ppm DM basis for birds, 50 ppm for rhinoceroses, and 65 ppm for lemurs have been recommended, but it is difficult to formulate balanced diets this low.…”

“…10,40,60,72 Hidden sources of extra iron include other minerals such as dicalcium phosphate and drinking water. 33,34,58,60,63,72 This was shown to be effective in lemurs by following %TS. Periodic removal of commercial pellets (for 30 days once or twice a year) from the diet decreased iron analytes in birds of paradise.…”