Cataracts, goitre and infertility in cattle grazed on an exclusive diet of Leucaena leucocephala.

Gross and histopathological changes and serum thyroxine levels were determined in 10 heifers fed an exclusive diet of Leucaena leucocephala from 10 months of age until slaughter, 23 months later. Normal ovarian activity and mating were observed during a 7-month mating period. Cataracts, goitre, lingual epithelial ulceration and gingival atrophy were present at slaughter. Only one of the heifers was pregnant. Histologically, severe vacuolation and disruption of lens fibres and focal hyperplasia of lens epithelium were present. Both follicular hyperplasia and colloid accumulation were found to varying degrees in the thyroid glands and serum thyroxine levels were higher than in a comparable group of animals not fed L. leucocephala. Morphologically normal trophoblast was present in the uteri of 6 animals even though no embryo or foetus was present. Embryonic death and resorption may have been due to the anti-mitotic effect of mimosine or the goitrogenic effect of DHP.