Rabbit Production. James I McNitt
but whatever the size of the proposed undertaking, the construction and equipment should be planned to save labor in caring for the herd. Neatness in design and convenient arrangement of the equipment for the rabbitry will make for a pleasant environment in which to work and will also create a favorable impression on prospective buyers of breeding stock or rabbitry products.
Before deciding on a location for engaging in rabbit raising and investing too much capital, you should thoroughly consider your own local conditions and such items as available markets and labor. In a town or city, check to make sure that no local ordinance forbids such an enterprise.
Planning the Rabbitry
The construction of the rabbitry can require a major outlay of capital or a minor one, depending on the decisions made in the beginning. Many times, a rabbitry is started in whatever building or structure is available. While this usually is the most economical decision, it often does not consider labor in caring for the rabbits, ventilation for controlling respiratory diseases, or room to expand if things go well. However, it does provide a starting place, and, if limitations are recognized, it is a good way to begin. It gives the opportunity to “get one’s feet wet” in the art of raising rabbits with a minimal investment. If the rabbitry is thought of as being temporary, a great deal can be learned about one’s abilities and desires to raise rabbits. Then, later, if the experience proves stimulating or profitable, plans for a new rabbitry or expansion of the old rabbitry can be approached with firsthand experience instead of “idealistic” concepts. Rabbit raisers say that one shouldn’t “go” into the rabbit business. You should “grow” into it.
After one to three years of raising rabbits, visiting other rabbitries, talking to many people about their mistakes and yours, and reading extensively on rabbit raising, you will be prepared to design and build your own rabbitry. Consideration must be given to the climate of your area, the prevailing winds, soil drainage, building space available, the size of the rabbitry you desire, and the money available to invest. Design the rabbitry on paper. Then show your plan to knowledgeable rabbit raisers and get their opinions. If possible, discuss the design with an agricultural engineer from the Cooperative Extension Service. Don’t be locked in to one concept. Modify your design if someone who is successful in raising rabbits suggests a logical change.
There are some basic concepts to keep in mind. A long, narrow building with a single tier of cages is much easier to ventilate than a wide building or a building with multiple tiers of cages. On the other hand, a long building requires more walking and does not house as many rabbits as a wide building or a building with multiple tiers of cages. Another concept concerns the production of ammonia gas from the excrement of rabbits as it reacts with water. Either this production must be minimized or excellent ventilation must be provided for its removal, or a combination of both. In cold climates, rabbitries are often designed for human comfort and not for the rabbits. The buildings are closed up and sometimes heated. Both of these procedures can be deadly for rabbits unless adequate ventilation is provided to carry away the toxic gases. Rabbits are much more susceptible to heat than cold. The economics of heating or cooling a rabbitry must be taken into consideration. Any increase in utility costs over lights and fans may decrease your profit. Another consideration in design is the ability to expand as needed. A modular design is ideal, because adding new modules is usually a very economical way to expand. Not only does it allow capital to be infused into the rabbitry at a later date, but it also gives one the ability to modify the construction design on the next module to take advantage of experience.
There are other factors to consider before actually beginning construction of your rabbi-try. Do local ordinances permit this type of enterprise? Will extra-territorial jurisdictions result in future ordinances against a rabbitry? What kinds of permits are necessary for construction? What types of building materials are most economical? What finances do you have? Is a loan needed?
The Rabbit Building
Modern commercial rabbitries are generally of pole frame construction, with metal sides and roof. They are of two basic types: those with natural ventilation and those with a controlled environment. A building with natural ventilation in temperate climates may have an open side toward a direction that does not have prevailing winds. In some areas, such as Arkansas, rabbitries commonly are open-sided, with a roll-up curtain of plastic, burlap, or canvas that can be dropped down in the winter and rolled up in the summer for better ventilation (Fig. 4.1). With natural ventilation, only one tier of cages should be used, and a long, narrow building is desirable. A central alleyway with a row of cages on each side works well.
Fig. 4.1. A Louisiana rabbitry with side flaps that can be closed during inclement weather. (Courtesy of J.I. McNitt)
Ventilation of rabbitries removes moisture, gases, microorganisms, and heat. Generally, ventilation is required in the summer to remove heat and in the winter to remove moisture. An ideal environment is about 10° to 15°C with about 50 percent relative humidity. When ventilation is adequate to lower heat or moisture to desired levels, the microorganisms and gases (mainly ammonia) are usually removed adequately also.
There are several characteristics of air important in designing ventilation systems. The higher the air temperature, the greater its capacity to carry moisture as water vapor. Agricultural engineers use charts relating air temperature to water content to determine the air volume necessary in the winter to carry water vapor from the rabbits’ breathing, from their urine, and from spilled water (e.g., from leaky drinking valves) out of the building. Another property of air is that hot air rises and cold air sinks. This characteristic is used in locating the air inlets and determining their optimal size.
Natural ventilation systems use wind and animal heat to move air. Advantages of natural ventilation include low cost and freedom from effects of power failures. Disadvantages are the lack of control over air movement, inability to lower the inside temperature of the rabbitry below outside (ambient) temperature, and overventilation (drafts).
Mechanical ventilation systems are employed in environmentally controlled buildings, using fans to provide the required air flow rate. Advantages include the potential of controlling the air flow rate to required levels for removal of moisture and heat and the ability to use the system to provide heat in cold weather. Disadvantages are the high initial and operating costs and the need for back-up systems in case of power failure.
Mechanical ventilation systems are of two types: positive pressure and negative pressure. In a positive pressure system, fans blow air into the building, creating a build-up of pressure inside. The major disadvantage of this type is that the pressure drives warm, moist air into cracks in the building and into the insulation in the walls and attic. In the winter this may result in excess condensation. Negative pressure systems are those in which the fans blow air out of the building, resulting in the inside air pressure being lower than the outside or atmospheric pressure. Negative pressure systems are more commonly used than the positive pressure type.
Movement of air in mechanically ventilated buildings is controlled by the placement and size of the air inlets. An inlet controls the direction, path, and distribution of fresh air into the rabbitry. In the summer, a lot of turbulence and air volume are needed for cooling purposes. In the winter, less air movement is required for removal of heat. Many rabbitries have insufficient ventilation in the winter, resulting in severe build-up of ammonia. Often this is followed by a high incidence of snuffles and pneumonia in the spring. Ammonia causes severe damage to the cells in the nasal passages, allowing Pasteurella bacteria to colonize. High humidity increases the problem, because ammonia dissolves in the water molecules in the air. Thus, high humidity means high ammonia. Some ventilation systems use ducts to carry fresh air from outside the rabbi-try directly to each cage.
Outlets in mechanical systems should be located on the walls so that air does not have to move more than 12m to