Effect of ingested snakeweed (Gutierrezia microcephala) foliage on reproduction, semen quality, and serum clinical profiles of male rats.

To examine the effects of ingested snakeweed foliage (SW) on male fertility and reproduction, SW collected at prebloom stage was dried, ground, and mixed with ground commercial rat feed (CRF) as 0, 12.5, and 25% of total diets. Male rats fed SW for 20 d impregnated females as successfully as did dietary controls, but males fed 12.5 or 25% SW for 40 d had seemingly impaired fertility and apparently increased mortality of offspring. Males fed SW for an additional 30 and 42 d showed no differences (P > .05) in serum testosterone or LH concentrations after a GnRH challenge compared with controls. Semen samples collected from the vas deferens revealed that total sperm concentrations were similar (P > .10) between rats fed 12.5 or 25% SW and controls. The percentage of abnormal sperm was higher (P < .01) in rats fed 12.5 or 25% SW for 102 d, compared with the percentage of abnormal sperm in controls (11.5 and 17.8 vs 10.4%), and weight of testes was decreased (P < .05). Dietary SW increased (P < .01) activities of alkaline phosphatase and gamma-glutamyl transpeptidase over those in controls at d 20 (but not at d 98) and hepatomegaly was evident at d 50 and 98. Ingestion of snakeweed foliage by male rats increased abnormal sperm counts, impaired reproduction, and caused hepatotoxicosis.