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Rhino Nutrition Update AAZK, 2005. Rhino TAG Nutrition Advisory Group. Ellen Dierenfeld, Chair (Sumatran) Marcus Clauss, Univ Zurich (Black) Michael Schlegel, Disney (White) Kerrin Grant, Utah State (Asiatic). Q/A from Zookeeper Survey (thanks to Dawn Strasser!!).
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Rhino TAG Nutrition Advisory Group • Ellen Dierenfeld, Chair (Sumatran) • Marcus Clauss, Univ Zurich (Black) • Michael Schlegel, Disney (White) • Kerrin Grant, Utah State (Asiatic)
Q/A from Zookeeper Survey (thanks to Dawn Strasser!!) • New nutritional concerns • Doses of vitamin E; how often evaluate • Update on White Oak pellet feed study • Tannins for binding iron – feed study • Forages: timothy vs. Alfalfa • Browse – length of time to feed out and still maintain nutritional/enrichment value; if root on plant, degrades less?
Q/A from Zookeeper Survey (thanks to Dawn Strasser!!) • Specific foods NOT to feed? • Perennial ryegrass staggars • D toxicity? • Pregnancy changes in diet
Diseases with Possible Nutritional Links - Black Rhino • Hemosiderosis - mineral imbalances • Hemolytic anemia - vitamin E, antiox • Ulcerative dermatitis - glucose, amino acid, fatty acid, mineral imbalances • Peripheral vasculitis (IHV) - vitamin C, antiox, minerals, fatty acids • Overall impaired immune function
Research Updates: • Mineral Survey, Tissues & Blood • Novel Antioxidant Metabolism • Tannin Binding Salivary Proteins • Intake trials in Indian Rhinos • Field Studies: • Vitamin E & Fatty Acids in Native Browses • Serum Vitamin E in Rhinos in South Africa • Field Ecology Studies – South Africa, Namibia • New Initiatives
Minerals in Rhinos E.S. Dierenfeld (St. Louis), S. Atkinson (Muskingum College), A.M. Craig (Oregon State), K.C. Walker (Oregon State), W.J. Streich (Berlin) & M. Clauss (Zurich) Zoo Biology 24:51-72 (2005)
Mineral Highlights • Serum/plasma • Zoo blacks (n=34); Free-ranging (n=27) • Zoo whites (n=3-16); Free-ranging (n=5) • Indian (n=3), Sumatran (n=3) • Liver (21 blacks, 6 whites, 2-4 Indian & Sumatran) • Horse a good model of metabolism • Rhinos ‘er blood Ca & Se (captive only); low Na compared to equids • Browsers high Fe (blood & liver) • Browsers low Cu (liver) – grazers high • Liver K, Mg, Co, & Mo with age
Iron Issues – Browsing rhinos • Captives & females higher
Iron Issues – Browsing rhinos • Females higher, both sexes increase with age
Linked with low tannins? Antiox, increased availability of iron but not solely diet Lack of fiber? Also can increase Fe bioavail – again, soluble CHO may be important Influence of dietary vitamin C? (citrus effect doubtful - native browses likely high) Iron Issues – Browsing Rhinos
Elevated Free Tyrosine in Rhinoceros Erytrhocytes Weber, B.W., D.E. Paglia, E.H. Harley Comp Biochem Physiol 138:105-109 (2004)
Tyrosine in rhinoceros RBCs (but not plasma) 50-fold higher than humans Also elevated in other Perissodactyla Captives significantly lower compared to free-ranging; also variation across species Function as antioxidant?
Tannins & Rhinos M. Clauss, Munich (now Zurich); J. Gehrke, J. Fickel, & M. Lechner-Doll, Berlin; E.J. Flach, Whipsnade; E.S. Dierenfeld, WCS (now St. Louis); J.-M. Hatt, Zurich Comp Biochem Physiol 140:67-72 (2005)
Salivary tannin-binding proteins (TBP) related to dietary habits – browsers highest Compared saliva samples from grazer (white, n=9), browser (black, n=10), and mixed (Indian, n=8) feeding habits Used hydrolyzable (tannic acid) & condensed (quebracho solution) tannin stds Tannin-Binding Salivary Proteins in 3 Rhino Species
Black rhino – bound both H & CT >> white Indian bound H = black, CT >> black Difference between black & white expected, results from Indian may indicate evolutionarily recent switch from browsing Tannin-Binding Salivary Proteins in 3 Rhino SpeciesResults……..
Related to dietary habits – browsers highest Black rhinos eat tannins in nature – seasonal dietary habits might benefit from inducible mechanism. Six animals (3 facilities) fed 3 mo: Regular diet Diet + 5% tannic acid pellet Diet + 5% quebracho pellet Tannin-Binding Salivary Proteins Inducible in Black Rhinos
Significant in tannic acid-binding capacity with both tannic acid and quebracho feeding n.s. trend for change in quebracho-binding capacity with quebracho feeding; no change with tannic acid feeding Hydrolyzable tannins play a greater role in native environment of rhino? HT >> CT at iron binding? Ongoing trials both in Europe & the US, with Fe balance Induction of Tannin-Binding Salivary Proteins …. Cont.
Indian Rhino Nutrition:Zoo Study M. Clauss, C. Polster, E. Kienzle, H.Wiesner, K. Baumgartner, F. von Houwald, W.J. Streich, E. S. Dierenfeld Zoo Biology 24:1-14 (2005)
Aims of the Study • Chronic foot problems, leiomyomas – linked with excess body weight? • Intake, Digestion • difference between zoo diets • (Nürnberg, n=2; München, n=2; Zurich, n=3; Bronx, n=4) • Diets with or without concentrates • Mineral (Ca) metabolism • Water intake
Zoo Diets • Nürnberg Grass hay, grass silage, pellets, Fruit & vegetable, mineral biscuits • Munich Grass hay, pellets, fruit & vegetable, mineral • Basel Straw, pellets, hay cobs, fruit & vegetable • Bronx Mixed hay, pellets, (minimal) produce
Results: • consumed 0.5-1.1% of body weight (DMI) daily • digestible energy 0.27-0.99 MJ DE/kg BW0 .75 (compared with est. reqt. 0.49-0.66) • 64% (7 of 11) consumed more energy, even on roughage-only diet • Water intake 30-49 mL/kg BW daily (~equid)
Results: • hay ad libitum diet is possible BUT • mineral &/or vitamin supplement needed • straw + concentrate diet: • energy provision as good as hay only diet • May need to restrict both concentrate & forage
Ca-Metabolism in Rhinos • Similar to horses, rabbits • not dependent on Vit D (?) • Elimination: URINE • Consequence: • Ca-stones in bladder & kidney (reported in rabbits, horses; never in rhino) • Other minerals, similar to horses
Rhino Browse: Free-Ranging & Captive (n=12) (n=4) (n=44) (n=11)
FORAGES FOR RHINOS: • Best nutrient ratio to duplicate browse? More grass than legume – sol CHO (in grass) impt. ??? - needs investigation • Good quality grass forage & proper pellet (6:1) alone can meet maintenance reqts. • Alfalfa NOT considered browse. • Browse can have enrichment value even if nutrient profiles not maintained. • Degradation depends on nutrient; don‘t know effect of roots – worth testing. • Keep as palatable as possible.
Lucerne (Alfalfa) can be Problematic • High [ ] N, Ca, Mg • Increased hindgut pH • Very digestible, altered passage rate • Salivary buffering issues, acid/base imbalances more prevalent
Mineral Imbalances Due to Improper Forages? • Associated with lucerne (alfalfa) feeding – in both grazers & browsers
Grass Also Problematic? • Grass staggars reported with perennial ryegrass (Bluett et al., NZ Vet J 52:48, 2004) • Due to fungal endophyte with alkaloids; localized in leaf base (overgrazing) and seed heads (undergrazing) • Clinically – tremors, lethargy, staggar, collapse • Test for lolitrem B (>1 mg/kg DM) or don‘t use pastures/hay containing perennial ryegrass with wild endophyte
PREGNANCY DIETS (all rhinos): • NO increased need until last trimester & during lactation • Increased: • Calorie needs (about double) • protein reqts. (8-10 to 12-14%) • Ca (0.3 – 0.5%) and P (0.2-0.3%) • No other changes recommended with equine model • Best to alter digestibility of diet – increasing browse and/or legume forage (adds protein and Ca), possibly targeted concentrates - not double quantities per se due to physical limitations
Plasma Vitamin E in Free-Ranging Black Rhinos Mean = 0.86 ug/ml; similar to other studies Ndondo et al., 2004 S Afr J Wild Rec 34:100-102
Plasma Vitamin E in Free-Ranging Black Rhinos Clauss et al., 2002
Plasma Fat-Soluble Vitamins in Black Rhinos Clauss et al., 2002
Vitamin E Concentrations in Black Rhino Browses Ndondo et al., 2004 Dierenfeld et al., 1995 Ghebremeskel et al., 1991
VITAMIN E: • Recommended doses (dietary levels) of vitamin E: • Based on available information, ensure all species consume diets containing at least 50 IU/kg DM – up to ~200 IU/kg. • Not doses per se, but if eat 1% of body mass, a 2000 kg black will eat 20 kg DM X 50 IU = 1000 IU minimal. • Evaluate at least annually
Vitamin D Toxicity – an Isolated Problem in 2002 Manufacturer very responsive, no diet problem isolated Miller et al., summary, 2003
Fatty Acids in Black Rhino Browses (South Africa) • Seasonal shift - increased PUFAs (C18) in winter vs spring • No relationship with vit E levels but essential for vit E absorption Ndondo et al., 2004
Evidence of FA Deficiency in Black Rhinos • Browse composition (Zimbabwe & NA temperate spp.) • Fresh browse - a-linolenic (n-3) 15X >> linoleic (n-6); immediate oxidation • Zoo vs. free-range diet - linoleic 5X, linolenic 1/3 Grant et al., 2002, J. Wildl. Dis.; Wright, 1998
Clinical response to dietary FA supplementation Adding flax-based supplement altered w-3:w-6 ratios favorably Zoo diet - opposite effects on ratio Suedmeyer & Dierenfeld, 1998 Adipose tissue FA [ ] as measure of long-term diet effects 25% of rhinos (n=20) deficient in C18:2 (linoleic); >50% undetectable C18:3 (a-linolenic) No free-range tissue samples as baseline Fatty Acid Investigations - Zoo Rhinos: Short- & Long-Term Dierenfeld & Frank, 1998
Currently summarizing FA in rhino plasma (US and European zoos) vs. Free-ranging • Limit foods high in PUFAs unless adequate antioxidant (Polyphenolics? Vitamin E? Tyrosine?) • Concentrates higher than forages in PUFA
Ongoing Captive Nutrition Studies – Rhinos: • White Oak Browsing Rhino pellets – added St. Louis (n=1); others? • Busch Gardens – diet with increased soluble CHO, beet pulp (n=3 blacks) • Tannin feed additives: US and Europe – no updates submitted • Sumatran rhino feeding trial – Los Angeles – seasonal intake/digestion trials • Rhino Browse/Diet Database?
Ongoing Nutrition Field Studies – Black Rhinos: • Stephane Helary – University of Witwatersrand, South Africa. N. Owen-Smith, advisor. IRF initially funded • Earthwatch project – Waterberg Plateau, Namibia, also examining South African sites • Quantifying Fe, tannins, minerals & natural chelators, possibly ascorbic acid • Feed plants, feces • Different ecosystems, different seasons
IRF RFP 2005 - Priority Target Areas with Possible Nutrition Component(s): • Dietary/Nutritional links with disease or susceptibility • Dietary links with reproduction • Nutritional links with male sex skew