In the first experiment, blood levels of p-carotene were determined after i.m. administration of 7.4, 14.9, 22.3, 27.9 and 37.2 mu mol beta-carotene/kg BW3/4 (metabolic body weight), once a month in foursheep of the same breed and age. Blood samples were drawn 1 day after each injection and continued in two day intervals for 21 days. The lowest dose, leading to a detectable serum concentration, was 14.9 mu mol beta-carotene/kg BW3/4. AS th, higher dosages were given, higher blood levels were determined and the p-carotene remained longer in the circulation. In lactating sheep P-carotene was also found in milk.