EFFECT OF TOTAL INTACT GLUCOSINOLATE INTAKE FROM RAPESEED MEALS WITH OR WITHOUT THIOGLUCOSIDASE (EC-3231) OR COPPER ADDITIONS TO THE DIET ON THE CONCENTRATIONS OF 1-CYANO-2-HYDROXY-3-BUTENE IN THE ILEAL DIGESTA AND FECES OF GROWING PIGS

Studies were made in pigs with cannulae sited near the terminal ileum of concentrations of the nitrile 1-cyano-2-hydroxy-3-butene (CHB) in i leal digesta and faeces consequent from varying daily total intact glu cosinolate intakes induced by including in the diet rapeseed meals (20 0 g kg-1) of different total intact glucosinolate concentrations but o f similar individual glucosinolate proportions with progoitrin predomi nating; a soyabean (SBM) based diet was used as the control. Ileal con centrations were determined from daily intakes (mmol x 10(3)) of 3.5, 23.7 and 53.8, the latter with or without the addition of 200 mg kg-1 copper (Cu) to the diet. Ileal and faecal concentrations were determin ed, with or without the addition of thioglucosidase (Thio) (EC 3.2.3.1 ) to the diet, from a daily intake of 46.6 x 10(3) mmol. No CHB was fo und either in ileal digesta from the SBM based diet or in faeces from this or from the rapeseed meal based diets. CHB was found in highly va riable concentrations between individual animals in ileal digesta when daily total glucosinolate intake was 23.7 x 10(3) mmol or above with peak concentrations recorded at between 2.5 and 5.5 h after feeding. W ithin this 3 h period Thio and Cu additions gave inconsistent and very small effects. Whilst these experiments provide evidence of the produ ction of CHB in the foregut of the pig, the significance of this findi ng relative to either deleterious effects in the animal and/or the pro duction and absorption of CHB in other parts of the gut is not clear a nd awaits elucidation from further work.