Biomedical Engineering Reference
In-Depth Information
require that run-off from animal housing enclosures be
contained and prevented from entering designated wetland
areas or watersheds. A soil surface is only practical in very
large enclosures such as field cages, corrals, or islands. If
possible, the soil surface should be planted with grass or
other vegetation appropriate to the area. Grass and vege-
tation provide a medium for foraging and grazing behavior
and may reduce aggressive behavior. The number of
animals allowed in enclosures planted with vegetation
should be appropriate to the enclosure size so that the
vegetation will survive the foraging and grazing activities.
Irrigation must be provided to support the vegetation during
periods of drought. It may be beneficial to consult local
agriculture extension agents or pasture specialists regarding
the selection of vegetation, soil fertilization, and weed and
pest control programs. Grass substrates do not hold up well
in baboon enclosures, as baboons tend to pull out all the
vegetation during foraging activities.
Areas of the soil surface around the climbing structures
and shelters should be cleaned manually on a regular basis.
These soil surfaces allow natural biological degradation of
waste. Soil surfaces cannot be sanitized and may harbor
parasites or microorganisms such as Clostridium tetani
(
Rawlins and Kessler, 1982
)orFrancisella tularensis (
Iliff
et al., 1996; Maetz-Rensing et al., 2007; Ferrecchia, 2011
).
deteriorate rapidly and require routine maintenance. Floors
should not be surfaced with materials that are potentially
toxic to animals (
McNulty and Griffin, 1976; Altman et al.,
1979; Geistfeld et al., 1982
). Concrete floors may not be
desirable in cold weather because they absorb body heat.
These floors should be heated in certain climates to
promote drying and provide a warm surface for the animals.
Heating can be accomplished by use of circulating warm
water in pipes that are installed in the floor as it is poured.
Alternative electric floor heating also may be considered.
Floors require installation of drains connected to a sewage
system. Floors should be adequately sloped with a recom-
mended minimum pitch of 0.25 in/ft (2.1 cm/m). Drains at
least 6 in (15.2 cm) in diameter are recommended (
National
Research Council (Institute for Laboratory Animal
Research), 2011
). Concrete floors limit the opportunities
for foraging unless they are covered with straw or other
bedding material. When bedding materials are used, they
must be removed on a regular basis.
Elevated Floor/Perch Surfaces
Elevated grid floors may be installed in small group
housing enclosures to keep the animals off the ground and
simplify the sanitization procedures. Grid floors may be
constructed of metal, fiberglass, plastic, or polyvinyl
chloride (PVC). Galvanized metal grid material should be
avoided to prevent zinc toxicity (
Obeck, 1978; Stevens
et al., 1978
). During freezing weather, direct exposure of
animals' skin to metal surfaces may cause dermal injuries
because the skin of the hands, feet, or tongue may adhere to
the metal surface. Perches and other raised surfaces may be
constructed of metal pipe covered by a sleeve of PVC pipe.
PVC is easily sanitized and is resistant to destruction. PVC-
covered perches are more comfortable for primates in cold
weather than metal perches. Other options are plastic or
composite materials such as floor grating products designed
for industrial construction applications. These types of
surfaces can last for many years with minimal maintenance.
When constructing perches with this material, any exposed
metal should be aluminum or stainless steel to prevent
rusting.
Rock Surfaces
Ground surfaces of outdoor enclosures may also be covered
with rock or gravel. The rock should be sized and shaped to
prevent compaction of the rock surface. Small rock frag-
ments, if consumed by the animals, can cause digestive
disturbance. Clean rock surfaces by periodical raking.
Frequent removal of feces and uneaten food improves the
sanitation of the ground surface. The total removal of the
contaminated rock and replacement with clean rock on
a regular basis may be necessary depending on species and
numbers of animals housed, climate, subsoil percolation,
and other factors. Designate an area for safe disposal of
contaminated rock. Rock for ground surfaces may be
economical if the rock is available locally. In some states,
rock surfaces may require a sewage collection system.
Concrete Surfaces
Concrete floor surfaces are commonly used for smaller
sized outdoor or indoor/outdoor group housing enclosures.
The floors should be finished to provide a smooth, sealed,
seamless, and water impervious surface that is easily
sanitized. Care should be taken during the finishing of the
floor to provide a smooth, easily sanitized surface, but not
so smooth as to create a slipping hazard to the animal care
personnel or the animals. Coating the surface of concrete
floors with nontoxic materials such as epoxy resins
prolongs
Animal Observation, Identification, and
Handling
The observation and handling of nonhuman primates
housed in large enclosures are more difficult and compli-
cated than for cage-housed animals. The degree of diffi-
culty is directly proportionate to the size and complexity of
the enclosure. Animals housed on islands with natural
vegetation are usually observed and captured when they are
fed in enclosed feeding stations. Animals housed in corrals
or field cages must be observed from towers, observation
the life of
the floor. Unsealed floors can
