The fattening swine were rationed with different portions of rapeseed meal

terramycin

berberine hydrochloride and andrographolide. The effects of these factors on the uptake of radioiodine (

131

I) in thyroid glands and on the serum level of thyroxine (T

4

) and swine's weight gain per day were observed. The results indicated that the uptakes of

131

I

serum levels of T

4

and weight gains in the groups rationed with rapeseed meal of less than 18% were higher than that of the control group; the highest was that of the group fed with 12% rapeseed meal. When the swine were rationed with 100~1500ppm terramycin

the

131

I uptakes and weight gains were higher than that of the control

but the T

4

levels were lower than that of the control. In the groups rationed with 10ppm berberine hydrochloride or andrographolide the

131

I uptakes

T

4

concentration and weight gains were higher than that of the control. In the groups supplied with 50ppm of berberine hydrochloride or andrographolide

the

131

I uptakes and T

4

concentration were lower than that of the control; but the weight gains were still higher than that of the control. The data obtained would contribute to the understanding of the relationship between thyroid function and weight gain of swine

and to the make-up of diet for swine.