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IRRADIATED DIETS FOR REARING GERM-FREE GUINEA PIGS

Journal Article · · Proc. Animal Care Panel
OSTI ID:4717243

Because of the destruction of some vitamins, especially thiamin and ascorbic acid, during steam sterilization of diets, studies were conducted on sterilization by high-speed electrons. Complete rations for rearing germfree guinea pigs were sterilized successfully by a dose as low as 2 megarad from a Van de Graaf electron beam accelerator. While conventional guinea pigs maintained on a natural diet sterilized at 3 megarad grew reasonably well and reproduced satisfactorily, the same diet failed to provide the necessary nutritional requirements for rearing germfree animals. A semisynthetic ration sterilized at 2 megarad produced germfree animals of good quality as regards early growth and general physical condition. The fact that conventional animals receiving the sterilized semisynthetic diet grew at a faster rate suggests that unidentified or additional growth factors are contributed by the action of the intestinal microflora. The problem remains whether these can be identified and furnished by a sterilized synthetic diet. Additional studies will be required before the diet can be evaluated for its adequacy to support reproduction and subsequent generations of germfree animals. There was little difference in the weight of the cecum between the 2 groups, although in the conventional animals it weighed slightly more. The weight of the contents of the cecum was somewhat higher in the germfree group, constituting 8.8% of body weight, compared with 5.8% for conventional animals. The hemoglobin and hematocrit values were essentially the same for both groups, but fewer white cells were observed in the germfree group. A technique using 3% peracetic acid as a germicide is also described for transferring sterile diets to the germfree enclosures. The convenience of handling the radiation- steriiized diet, once it has been transferred to the germfree system, seems to outweigh some of the disadvantages associated with monitoring the sterilization process. With the necessary modifications, other sources of irradiation can be employed in a similar fashion to sterilize complete or basic diets for the same or other germfree species. (H.H.D.)

Research Organization:
National Inst. of Allergy and Infectious Diseases, Bethesda, Md.
NSA Number:
NSA-17-027004
OSTI ID:
4717243
Journal Information:
Proc. Animal Care Panel, Journal Name: Proc. Animal Care Panel Vol. Vol: 11
Country of Publication:
Country unknown/Code not available
Language:
English