Until recently, effects on rabbits of elements of the environment such as temperature, humidity, pressure, light, and air quality were not recognized. Deterioration of a combination of any of these factors may be responsible for the demise of many rabbitries.

To maintain rabbit production at a constant peak (with nest box mortality at 5% or less, fryer mortality of 3% or less, feed conversion ratio of less than 3:1, breedability at 98%, and conception rate at 90% or better), a reliable thermometer, barometer, and humidistat are necessary to monitor these criteria:

(a) Clean air and virtually no airborne ammonia present.

(b) Temperature not over 70F in summer, not under 50/60F in winter.

(c) Humidity constant @ 50% or less.

(d) Barometric pressure constant @ 29.5 - 30.5 inches.

These objectives are only possible to meet in the controlled environment of a carefully designed and constructed rabbitry. A variation between b, c, and d will result in some undesirable symptoms including: higher feed intake, lower gains in a given period, poorer conversion ratios, and higher death rates.

After reading this information and considered how my rabbits used to be kept in an environment where they were at the mercy of the weather, one realizes it is a testament to their toughness that they survived at all. However, to realize success at raising rabbits, a proper barn must be built with adequate environmental controls. Those items are listed on the next page:

Factors in creating the proper environment:

INSULATION - It is cheaper to insulate well rather than compensate later. A water vapour is necessary to inhibit condensation inside the walls. The building should be windowless. The ceiling should be insulated better as this is where most of the insulating effect takes place. Storage of hay in the loft makes a good insulator.

VENTILATION - An adequate air flow (cfm) replaces the entire inside air volume at least 16 times/hour according to Agriculture Canada. A positive air system is one in which the inside air pressure is made higher than outside by forcing air into the building. This method provides a uniform air flow, enables the treatment of incoming air, and creates a draft free environment. A negative air system is unsatisfactory for rabbits as it uses forced air exhausts and causes drafts that make it impossible to treat incoming air.

EXHAUST - Ammonia is heavier than air and can be collected best if ventilation exhausts are positioned low. There should be several exhaust vents to inhibit the creation of "dead-air" pockets. When required, they should be motorized to increase air exhaust, and decrease inside air pressure.

DEHUMIDIFICATION - A standard de-humidifier provides both, cooling and drying of the air in the Summer, however it becomes useless in cold weather. Remove excess water from the floor.

HEATING - Some people swear by 50F, while others maintain 60F. Each rabbit exudes 5 to 7 BTUs/hr. With a large herd, the temperature outside must fall considerably lower than inside to overcome its heating effect. Heating devices are built into forced air input vents, creating a warmer dryer air flow. On particularly cold days, additional heating devices may be necessary.

COOLING - Increased Ventilation, dehumidification, reducing the number of rabbits, and the effects of water in the barn will lower temperatures. A cheap cooling method is to place ice blocks under incoming air. Cooling by spraying cold water increases humidity & is not practical if the humidity goes above 50%.

LIGHTING - Although adequate lighting is required when doing chores in the rabbitry, during the rest of the time very little light is necessary. Enough lighting is required only to duplicate the light from the stars on a moonless night (5 lumen/square metre.) Activated by a timer, this light should be on for at least 16 hrs per day, year-round, for does to realize their optimum fertility.

Provide bucks with stronger light for only eight hours per day. They will mature earlier and have a higher testosterone level.

FILTERING - Micro-Organisms must have a vehicle to attach themselves. This may be dust particles, water or water vapour. The average virus measures 5 to 6 microns and can be effectively filtered out in a negative air system by a mechanical filter that can filter down to 1 to 2 microns. Other forms of filtering are available such as Particle Ionization, Bacticidal, and Biocidal Paint but are comparably more expensive. This filtering is not necessary in a positive air system.

MANURE HANDLING - The major source of ammonia and bacterial air pollution; manure should be removed often. Water assisted removal or belt manure handling are the only two alternatives. Water will increase the humidity and a belt system is too expensive, so frequent manure removal is the only viable method. Scattering of new sawdust will extend the removal cycle.

Equipment costs can be reduced if you maintain a dry and ammonia/acid free environment.

Hal MacGregor