Metabolism of [14C]Formaldehyde When Fed to Ruminants as an Aldehyde-Casein-Oil Complex

Abstract

Formaldehyde has been used to protect proteins and lipids from metabolism in the rumen, and the present studies were designed to investigate the metabolism of [140]formaldehyde when given to ruminants as an aldehyde-casein-oil complex. Approximately 60-80% of the consumed [140]formaldehyde was metabolized to carbon dioxide and methane, a further 11-27% was excreted in the faeces, and 5-6% was accounted for in the urine. The amount of radioactivity excreted either in the expired air or faeces appeared to be dependent on the length of the reaction time between the aldehyde and casein prior to feeding. Small amounts of 140 radio� activity were detected in body tissues and milk, but this was not present as formalde� hyde. It is concluded that ruminants effectively metabolize formaldehyde and there is no accumulation of this compound in the carcass or milk.