Effect of Methionine and Age of Rat on the Occurrence of Hemorrhagic Diathesis in Rats Fed a Ration Containing Irradiated Beef

Abstract

There was no mortality in weanling Sprague-Dawley rats fed non-irradiated beef. A significant (P < 0.01) number of deaths occurred in the group fed the irradiated-beef ration. Methionine reduced the mortality rate linearly (P < 0.01). The prothrombin rate (reciprocal of prothrombin time × 1000) of rats fed an irradiated-beef ration was lower (P < 0.01) than that for rats fed a ration containing nonirradiated beef. The prothrombin rate increased (P < 0.01) when the ration was supplemented with methionine. Growth was depressed (P < 0.01) by dietary methionine. Some adult Sprague-Dawley rats died of internal hemorrhages when fed a ration containing nonirradiated beef, indicating adults were more susceptible than weanling rats to hemorrhagic diathesis. Feeding irradiated beef increased the mortality (P < 0.01), but it was decreased (P < 0.01) by supplemental methionine. The methionine required to prevent hemorrhagic disease in adult rats fed nonirradiated-beef diet was less (P < 0.01) than that of rats fed irradiated beef. Feeding irradiated beef decreased the prothrombin rate (P < 0.01) and supplementation with methionine increased the rate (P < 0.01). There was a linear (P < 0.01) decrease of body weight gain with increasing supplemental methionine, which was less (P < 0.05) for rats fed non-irradiated beef than for those fed irradiated-beef rations.