A study of the feasibility of the use of gentian violet as a fungistat for poultry feed

A 96% formulation of gentian violet was fungistatic to Aspergillus flavus, Alternaria sp., Candida albicans, Fusarium moniliforme, and Penicillum citrinum when incorporated into corn meal agar at 6.5, 39.0, and 156.0 p.p.m. A. flavus, Alternaria sp., F. roseeum, and P. citrinum were inhibited on corn meal agar which had been amended with 12.8, 26.6, and 38.4 p.p.m. of gentian violet in a 2.54% commercial liquid concentrate of gentian violet employed as the active ingredient in a commercial poultry feed additive. Sporulation of these fungi was not inhibited by either of the formulations of gentian violet at any concentration. An anhydrous gentian violet poultry feed additive (containing 2.05% gentian violet) significantly reduced the numbers of A. flavus and F. moniliforme propagules recovered from artificially contaminated feed samples treated with 1,000, 2,000, and 4,000 g./1000 kg. of the additive (20, 40, and 80 p.p.m. of gentian violet, respectively) and stored for 12 weeks at 8.5% moisture and compared with the numbers of propagules recovered from contaminated-unamended samples. The numbers of propagules of F. moniliforme and C. albicans recovered from the pre-mix amended samples held for 12 weeks at 19% moisture also were fewer (significantly fewer for F. moniliforme) than those recovered from the contaminated, unamended feed. Amending the A. flavus or F. moniliforme contaminated feed samples did not reduce the numbers of propagules recovered below the numbers present in the original feed samples. GV was fungistatic to the test fungi under the conditions in these studies, since it inhibited, but did not prevent development of the test fungi. A. flavus and F. moniliforme were the fungi isolated in greatest numbers from the original sample.