Biomedical Engineering Reference
In-Depth Information
helpful for those species where dry matter intake ability has
been established. If the species of concern does not have an
established dry matter intake ability, it can be easily
determined through a 7-day intake study. Of course, if
animals are maintained primarily on the base, complete
diet, with strict control of the enrichment portion, there is
much less concern regarding the possibility that food
choice will compromise nutritional health.
primates. The rhesus macaque is the best studied species.
Nonhuman primates have been used as models for human
pathology caused by nutrient deficiencies. Thus there are
data on the effects of certain deficiencies for some species.
However, based on the data from human and rhesus
macaque studies, supplemented by data from other species
on specific nutrients, a general consensus regarding
appropriate dietary levels for most nutrients has been
achieved. The suggested dietary levels for all known
required nutrients for nonhuman primates are presented in
Table 10.1
.
The following sections review the scientific evidence
regarding requirements for the macronutrients (energy,
protein,
Over Nutrition
It is, unfortunately, very easy for animals to overeat and
under-exert in a captive setting. Overweight and obesity are
significant problems for many nonhuman primates in
captivity. Obese cynomologus macaques (
Chen et al.,
2002
) and common marmosets (
Tardif et al., 2009
) exhibit
suites of metabolic parameters similar to those that define
metabolic syndrome in humans (e.g. increased fasting
triglycerides and glucose, modifications of cholesterol
patterns). Obesity, with its possible link to cardiovascular
disease, is considered a significant concern in chimpanzees
(
Videan et al., 2007
). Because many captive primates in
research settings are constrained in their ability to be active,
dietary management often is the primary mechanism to
prevent obesity. Foods that are nutrient dense and complete
allow adequate nutrition to be delivered while restricting
caloric intake.
lipids, carbohydrates), and some vitamins and
minerals.
Energy
Energy is a fundamental need of all living things. In the
wild, satisfying energy requirements may be the most
important aspect of foraging ecology and feeding decisions.
In captivity, satisfying an animal's energy requirement is
usually not difficult. The concern is more over balancing
energy intake with the intake of other necessary nutrients.
The energy density of manufactured foods is normally
fairly high, and these foods are usually highly digestible as
well. Also, energy requirements for captive animals are
likely lower than those of their wild conspecifics due to the
nature of captivity. Captive animals generally are faced
with less thermal stress and less required physical activity.
In many cases, physical activity is actually constrained.
Overweight and obesity are much more likely conditions to
be found in otherwise healthy captive animals compared
with underweight.
Complete Feeds
Captive primates are often offered a variety of foods in
what is termed a cafeteria-style diet. This can complicate
assessments of whether any individual is receiving the
appropriate nutrition, especially for animals living in
a group situation. Standard best practice is for the base diet
to be primarily composed of a food (commercial primate
biscuit, canned primate food, primate gelled food, or home-
made primate formula) that is nutritionally complete.
A nutritionally complete food meets the nutrient profile
given in
Table 10.1
(modified from table 11-2, of the
2nd edition of The Nutrient Requirements of Nonhuman
Primates (
National Research Council, 2003
)). The food
chosen for the base diet must also meet the needs of the
specific group or species it is intended for (i.e. New World
primate, leaf-eating primate, Old World primate, etc.).
Different species will have different preferences and
constraints on the form of the base diet. For example, large,
extruded biscuits may be appropriate for baboons, but may
not be the best option for common marmosets.
Measuring Energy in Animals and Food
There are many ways to express energy use in animals and
the energy content of food. Briefly, energy requirements in
animals can be partitioned into the costs of resting meta-
bolic rate, thermal regulation, thermic effect of food (i.e.
cost of digestion and metabolism of food), activity, growth,
and reproduction. Energy content of food can be expressed
as gross energy (GE), digestible energy (DE), or, most
usually, as metabolizable energy (ME).
Energy Content of Food
The total amount of energy that could be released through
complete oxidation of a food is called its gross energy
(GE). This value is usually determined by combustion of
a sample in a bomb calorimeter. However, due to losses
during digestion and metabolism, GE overestimates the
amount of energy in a food that is actually biologically
available to an animal. Digestible energy (DE) is GE minus
PRIMATE NUTRIENT REQUIREMENTS
There are few studies which have produced definitive
data regarding the nutrient requirements for nonhuman
