Biomedical Engineering Reference
In-Depth Information
for including gum in the diet of captive, gum-feeding
primates. There are hypothetical advantages, such as
providing a fermentable substrate that would increase
butyrate production in the colon to enhance colonic health
( Wong et al., 2006 ). However, some starches and pectins in
captive callitrichid diets probably already reach the colon
to be fermented, providing a source of butyrate. Gum added
to the diets of common and pygmy marmosets appeared to
slow the passage rate of digesta ( Power, 1991; Power and
Oftedal, 1996 ). Whether a slower passage rate of digesta
would have any positive health benefits in captivity is
unknown. Based on the lack of evidence that gum has
a nutritional purpose in captive callitrichid diets, it should
be treated as an enrichment food. Gum arabic syrup has
been used successfully as an enrichment device for
marmosets ( McGrew et al., 1986 ).
FIGURE 10.1 Effect of time on diet vitamin C content. Primate diets
were extruded, then stored at 70 F, < 50% RH for 9 months. Data
represents duplicate assays for each sampling point. Samples were
analyzed for vitamin C at routine intervals (NP Analytical Labs, St Louis,
MO). (Data from Purina Mills internal research.)
Water Soluble Vitamins
The water soluble vitamins are vitamin C and the B vita-
mins (B 1 , thiamine; riboflavin, panthothenic acid; niacin;
B 6 , pyridoxine; biotin; folate; B 12 , cyanocobalamin), as
well as choline. All primates have a requirement for these
vitamins, although the actual requirements have only been
determined for few species other than rhesus macaques and
humans. Water soluble vitamins tend to be excreted from
the body relatively quickly, which generally means that
deficiency concerns are greater than any possible toxicities.
Accordingly, there are relatively wide ranges of intakes
considered to be safe for these nutrients ( National Research
Council, 2003 ).
complete feeds can be vitamin C sufficient, reducing the
need for supplemental foods.
Fat Soluble Vitamins
The fat soluble vitamins (A, D, E, and K) are generally
retained within the body longer than the water soluble
vitamins. Thus, deficiency can take longer to arise. For
example, in rhesus macaques fed a vitamin A deficient diet,
the first overt signs of deficiency appeared after about one
year ( O'Toole et al., 1974 ). This also implies that chronic
overnutrition in these vitamins has a greater likelihood of
eventually reaching toxic levels.
B Vitamins
The B vitamins have been shown to be important for neural
function, especially vitamins B 6 ,B 12 , and folate. Experi-
mentally induced vitamin B deficiency causes cognitive
impairment in mice ( Troen et al., 2008 ). Supplementation
with B vitamins had a neuroprotective effect in an epileptic
mouse model ( Rabie et al., 2010 ). Supplementation with
vitamins B 6 ,B 12 , and folate slowed the rate of brain
atrophy in elderly humans with mild cognitive impairment
( Smith et al., 2010 ). An attention to dietary B vitamin levels
for geriatric primates may be warranted due to reductions in
food intake and absorption efficiency ( National Research
Council, 2003 ).
Vitamin A
There are a number of compounds that have vitamin A
activity. The reference substrate is all-trans-retinol, and
vitamin A is often referred to as retinol. The biological
activity of vitamin A is measured in International Units
(IU); 1
g of all-trans-retinol is the equivalent of 3.33 IU of
vitamin A.
VitaminA is of animal ormicroorganismorigin; however,
some plant carotenoids (e.g.
m
-carotene) can be
metabolized by nonhuman primates to produce retinol
products. Indeed, carotenoids are the likely source of vitamin
A for most nonhuman primates in the wild. Among the
provitamin A carotenoids,
b
-carotene,
a
Vitamin C
All primates require vitamin C. Fruits, vegetables, and
leaves are generally good sources of vitamin C. In the past,
manufacturing processes tended to degrade vitamin C,
complicating its provision in a complete feed. New vitamin
C formulations are more stable ( Figure 10.1 ), and now
-carotene has the greatest
vitamin A activity, about twice that of other provitamin A
carotenoids such as
b
a
-carotene and
b
-zeacarotene ( National
Research Council, 2003 ).
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