Effects of Gamma Irradiation and Pasteurization on the Nutritive Composition of Commercially Available Animal Diets
View/ Open
Date
2008Author
Caulfield, Catherine D.
Kelly, John P.
Metadata
Show full item recordUsage
This item's downloads: 316 (view details)
Recommended Citation
Caulfield, CD,Cassidy, JP,Kelly, JP (2008) 'Effects of Gamma Irradiation and Pasteurization on the Nutritive Composition of Commercially Available Animal Diets'. Journal Of The American Association For Laboratory Animal Science, 47 :61-66.
Abstract
Gamma radiation is used to sterilize diets for specific pathogen-free (SPF) animals. Because a gamma-irradiated diet was linked to leukoencephalomyelopathy in SPF cats, we investigated the effects of 'typical' (28.9-34.3 kGy) and 'high-end' (38.4-48.7 kGy) doses of gamma irradiation and of pasteurization (at 107 degrees C for 15 min) on the amounts of fat; protein; carbohydrate (and taurine in cat diet); vitamins A, E, B, B-1, B-2, and B-12; and peroxide in commercially available dry cat, dog, and rodent diets. The only treatment-related changes occurred with vitamin A and peroxide. The typical and high-end doses of gamma irradiation reduced the vitamin A level of the cat diet to 42% and 30% of the untreated value, respectively-levels below recommended allowances for growth and reproduction. Only the higher irradiation dose reduced vitamin A in the rodent diet, and neither dose altered the canine diet. Pasteurization reduced the vitamin A content of the cat diet to 50% of its original level, which was within the recommended level for this species. Irradiation increased the peroxide content of all 3 animal diets: by approximately 11-fold with the typical dose and by 14- to 25-fold with the high-end dose. Therefore gamma irradiation can have profound, selective effects on the vitamin A and peroxide contents of dry diets, and caution is advised when feeding such diets long-term and exclusively to SPF animals, particularly cats. Furthermore, pasteurization (with its fewer deleterious effects) may represent an alternative method of decontaminating diets for rodents, dogs, and cats.