 The research worker you see here is just about ready to chuck it all and go fishing. For the past four months he has worked on a detailed research project and has just met with failure in his verification of results. What is wrong? He's a qualified man provided with the very finest working tools in laboratory equipment. He knows where the trouble lies because in his own words it happens every day. His most important laboratory tools the animals he employs in research are unreliable. Somewhere along the line this animal became disease or suffered malnutrition or perhaps it was genetically impure or housed in a substandard environment. In laboratory animals supplied for research introduction of any one of those four factors disease malnutrition improper environment or the factor of genetics can seriously prolong or even nullify the results of an entire research project. This man knows through bitter experience that the quality of results of his entire project is directly related to the quality of the laboratory animals with which he is supplied. The research man you just saw probably received his animals from a colony like this it is typical of animal rooms throughout the nation. We've got a little of everything here it's a Noah's Ark collection of chickens rabbits guinea pigs rats mice and numerous other animals. Every day newly purchased animals are shipped in a diseased animal in that crate will spread a disease through this room like wildfire oftentimes it will spread from species to species. Factors of disease and environment cannot be controlled in a room such as this but something can be done about it. Let's look at a diagram of this same room remodeled to provide quarters for a properly established and maintained disease free animal colony. Here is the basic space to be remodeled. First step is to divide this area into one man rooms with storage space and an air condition unit in the center servicing the four rooms. Such rooms provide each man his own particular work area which is his responsibility. This instills into each attendant an individual pride in his work. There are no connecting doors between these rooms. Now since human beings are themselves carriers of disease how are we going to prevent the attendants in these one man rooms from infecting these colonies. The answer to this is the personnel lock. Note that each one man room has its own individual personnel lock. Air pressure in the lock is lower than that in the colony room. Air from the lock does not enter the colony room. We'll show you how the personnel lock works. The attendant enters closing the outer door behind him. He first removes his outer clothing and hangs it in the locker which has provided him. Before entering the clean area of the personnel lock he steps into the foot bath. Next step in his preparation is to disinfect the personnel lock with the portable spray tank. A sterile container is supplied from which he removes his packaged sterile clothing. After opening the package and before handling the sterile clothes he must thoroughly wash his hands. He must use the same precautions and procedures as a surgeon preparing for an aseptic operation on a human being. The attendant is now properly dressed to enter the colony room. As he enters the room he turns the door knob with a sterile sponge moistened with disinfectant. The attendant is now isolated in the colony room but how does he get his supplies and equipment? And how does he clear the colony room of used bedding, soil cages and the like? He is provided with an equipment lock. Everything in the way of supplies and equipment passes through this lock both entering and leaving the colony room. The attendant UC is about to pass some clean feed and bedding into the colony room. The interior of the container he holds is sterile. The bedding was autoclave before being placed in the container. The container is placed in the equipment lock. On the other end of the lock there is a closed inner door. Inside the colony room the attendant turns on the steam valve. Inside the equipment lock live steam is now thoroughly sterilizing the outside of the container. If steam is not available disinfectant may be used. Through the equipment lock passes all equipment feed and bedding. Pasteurized feed is packaged in hermetically sealed metal containers and all bedding and equipment are autoclaved and sealed in sterile containers. The attendant now gets rid of his soiled bedding through the lock. Soil material is also thoroughly steamed. As soon as the attendant outside has received the soiled material he closes the outer door to the lock. The attendant inside then turns on his steam valve and sterilizes the empty lock. Inside the colony room control of temperature and humidity is essential. The temperature should be uniform approximately 72 to 75 degrees Fahrenheit. Rapid changes in temperature can result in physiologic changes in the animals. Humidity should be maintained between 50 to 55 percent. Excessive humidity can interfere with the elimination of body heat. Low humidity levels will irritate the respiratory tract. Also of major consideration in producing healthy uniform laboratory animals such as these is the lighting factor. Brilliant or irregular lighting can cause nervous stress. Illumination should be uniform and provided by electric light. It should be adequate for the proper examination of the animals. Here you see the recently constructed animal colony building at the Forest Glen section of Walter Reed Army Medical Center. This building is completely insect and rodent proof and contains four disease-free colony rooms which are serviced through a screened runway. Each colony room contains the personnel lock equipped with a clothing locker, foot bath, wash facilities, sterile storage locker containing sterile clothing, sterile sponge, and the disinfectant spray equipment. It is the only personnel entrance to the colony room. Each colony room is serviced through its individual equipment block. The colony room attendant controls the steam valve for the equipment block. Each colony room is the responsibility of the one man assigned to that room. The proper size of the colony room is determined by the space required for the number of animals one man can care for. The Forest Glen colony rooms are 20 by 40 feet overall. Each colony room is equipped with one window only. This serves as an inspection window and also as a means of communication to and from the attendant inside. An intercom system from the colony room is a very desirable feature. Breeding stock for laboratory animals may be secured in two ways. From the animals maintained in a disease-free colony or by caesarean section from commercial stock, the main source of supply is use of the caesarean section. Caesarean sections are performed in an aseptic area under the same conditions of sterile procedure as applied in human surgery. Personnel in the surgery area are clothed and masked as in human surgery. Equipment includes the metal surgical table, instrument table, and auto-claved instruments. An incubator is provided as standard equipment for all caesarean sections. Temperature of 37 degrees centigrade is maintained. The surgeon today is Lieutenant Carl Miller of the Animal Husbandry section here. Lieutenant Miller, would you tell our audience the steps and procedures you and your assistant follow in routine caesarean sections? Certainly, Colonel Hale. My assistant is just finishing up the preparation of this animal. This animal has been anesthetized, the hair is being clipped from the abdomen, and then she is submerged and disinfectant up to the nose. This allows the mother to continue breathing and will keep oxygen available to the young and the uterus as long as possible. Caesarean sections should be performed during the last day of pregnancy, ensuring fully developed fetuses. One rat tooth, thumb forceps, and one pair of scissors is used to incise the skin only. The skin is then retracted. Another rat tooth, thumb forcep, and scissors is used for the remainder of the operation. After the abdomen is opened, the entire uterus with fetuses is removed from the female and placed in a sterile area. All connections between the mother and the fetuses are severed. All possible speed is used to prevent aspiration of fetal fluids by the young. A helpful shortcut is to expose the head of each infant before completely removing the uterus and fetal membranes. Keeping the nostrils free of fluid and massaging the young stimulates the gasp reflex and then regular breathing. Rhythmatic breathing means the young has passed the first crisis. The young are now transferred to the incubator, for they will remain for 15 to 20 minutes. Temperature is held at 37 degrees centigrade. While in the incubator, they are frequently moistened with sterile normal saline and massaged. Immediately after removal from the incubator, the animals are sexed. As a time and space saving measure, we keep four females to one male. This is the correct ratio for most animals. They are sexed after the incubator, since some may be lost during the incubation period. Here is a close-up of the male. Here is the female. For purposes of comparison, at left, the male, at right, the female. Following sexing, the animals are placed in filter-equipped cages and immediately transferred to the colony room. Thank you, Lieutenant Miller. Feeding the cesarean-born young is accomplished by several methods. Most time-consuming is hand-feeding. First, the formula must be prepared. This is a preparation consisting of one part water, four parts canned evaporated milk, and vitamin A and vitamin D in correct quantities added. The formula is now pasteurized at 160 degrees Fahrenheit for three minutes. It is then quickly cooled in a refrigerator. For hand-feeding, a small latex tube nipple is passed partially down the esophagus. These animals must be fed hourly for 16 hours a day during the first three or four days. Second method feeding is by foster mothers who are themselves obtained from colonies which were established by cesarean section and hand-fed. To prevent cannibalism, the prospective foster mother is separated from her newborn offspring and is placed in another cage bedded with a highly scented material such as cedar shavings or bedding impregnated with coal tar products. After the mother has spent several moments in the cage, the strange sucklings are placed in with her. The highly scented bedding prevents her identifying the strange young by their odor. She accepts them as her own. In addition to the major points already discussed, controlled physical environment, freedom from disease and genetics, the fourth major factor in establishing and maintaining a disease-free and uniform animal colony is proper nutrition. Presently, there are a few companies marketing pasteurized diets which are packaged in hermetically sealed containers. Where diets such as this are not available, the diets must be prepared by the colony personnel. Here, a technician is using an ordinary oven to pasteurize the feed. The feed is moistened and baked at 200 to 230 degrees Fahrenheit for 20 minutes. Baking times vary according to the amount of feed and moisture involved. Other necessary equipment for the maintenance of the disease-free colony includes the autoclave which sterilizes all feed packages, bedding, and equipment. This autoclave sterilizes the containers in which the supplies and equipment are transported to the colony room. Temperature in the sterilizer is 275 degrees Fahrenheit and is maintained for 45 minutes. Draped with sterile sheets, the container is taken directly to the colony room. The attendant immediately transfers the sterile container with the autoclave equipment to the equipment lock of the colony room. After a thorough steaming, the attendant inside receives his equipment. He also has a delivery of animals requested by a laboratory. The animals are placed in an air filter cage and sent out through the equipment lock. The air filter cage is now delivered by truck to the requesting laboratory. This man can now get back to work. He knows that the animals that he has just received are healthy and uniform. He knows that his laboratory tools are now all to standard because his laboratory animals have been provided by a properly established and maintained disease-free animal colony.