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Rapeseed Meals, Methimazole, Thiocyanate and Iodine Affect Growth and Thyroid. Investigations into Glucosinolate Tolerance in the Pig
Author(s) -
Schöne Friedrich,
Groppel Bernd,
Hennig Arno,
Jahreis Gerhard,
Lange Reinhard
Publication year - 1997
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199705)74:1<69::aid-jsfa771>3.0.co;2-0
Subject(s) - glucosinolate , iodine , meal , chemistry , cretinism , medicine , thyroid , factorial experiment , endocrinology , thiocyanate , zoology , antithyroid agent , rapeseed , iodine deficiency , food science , biochemistry , brassica , biology , agronomy , graves' disease , mathematics , statistics , organic chemistry
In two factorial experiments with a total of 81 growing pigs, the effects of antithyroid compounds and rapeseed meal (RSM) diets differing in glucosino‐late content were tested without or with supplementary iodine. In Experiment 1, a 4×3 factorial arrangement was used to investigate the effects of antithyroid compound inclusion and supplementary iodine. Pigs received a grain–soya bean meal diet (control) or this diet with 250 mg kg ‐1 methimazole (MMI), 1000 mg kg ‐1 thiocyanate (SCN ‐ as KSCN) or 80 g kg ‐1 high glucosinolate RSM (9·5 mmol glucosinolates kg ‐1 ), each diet supplemented without or with iodine; 0, 125 μg kg ‐1 (requirement) or 500 μg kg ‐1 . In Experiment 2, a 5×3 factorial arrangement was used to study the effects of dietary glucosinolate content and iodine supplementation. Pigs received a grain–soya bean meal diet or four diets with 160 g kg ‐1 RSM differing in glucosinolate content (0·6, 2·4, 6 or 19 mmol kg ‐1 diet), each diet supplemented with iodine: 62·5 μg kg ‐1 , 125 μg kg ‐1 (requirement) or 250 μg kg ‐1 . Irrespective of the iodine dosage, MMI suppressed production of thyroxine and resulted in goitre, myxoedema and cretinism. SCN ‐ induced clinical hypothyroidism when there was no supple‐mental iodine. Despite high iodine supplementation, glucosinolate load (19 mmol kg ‐1 diet) decreased growth, feed intake, iodine store of the thyroid and serum concentration of thyroid hormone and resulted in goitre formation. In the case of diets with ⩽6 mmol glucosinolates kg ‐1 , iodine prevented antithyroid effects. However, more iodine was required by these pigs than by control animals to a high T 4 serum concentration. The lowest glucosinolate level tested (0·6 mmol kg ‐1 diet) yielded the same thyroid hormone status and thyroid weight as the control, however, the iodine content of thyroid gland was decreased. In conclusion, iodine administration prevents the effects of a low glucosinolate intake only, by overcoming the depressed thyroxine released of the thyroid, resulting in regression of goitre. © 1997 SCI.