| High feed quality is imperative to profitable dairy and beef production. A multitude of factors, including molds, may adversely affect milk production or weight gain. Penicillium species are common contaminants of fermented feeds in the Upper Midwest and are known to produce several mycotoxins, including patulin. This thesis focuses on Penicillium molds isolated from fermented feeds with the potential to produce patulin, the adverse effects of patulin on rumen metabolism and the adverse effects of patulin on animal health and production.; Penicillium molds comprised 82% of isolates from fermented feeds. Three percent of these isolates produced patulin.; Single-flow continuous culture fermenters were used to study the effects of patulin on rumen microbial fermentation. Fermenters were spiked with 0, 10, 20, 30, 40, 60 or 90 ppm patulin every 12 hours for three consecutive days. True organic matter (OM) and protein digestion were decreased in the 20 to 90 ppm and 30 to 90 ppm patulin treatments, respectively. Neutral detergent and acid detergent fiber digestion were decreased in fermenters spiked with 10 to 90 ppm patulin. Bacterial nitrogen was lower in fermenters with 20 to 90 ppm patulin, whereas the efficiency of bacterial growth (g of N/kg OMTD) was only reduced in the 90 ppm patulin treatment. Total volatile fatty acid (VFA) and acetate production decreased in 10 to 90 ppm patulin treatments. Conversely, butyrate and valerate (mol/100 mol) increased in patulin spiked fermenters. At 60 and 90 ppm patulin, branched-chain VFA were lower. We conclude that patulin concentrations of 10 to 90 ppm adversely affects rumen fermentation in vitro.; Seven lactating ewes were dosed orally with 3.3 mg patulin/kg BW/day for 7 days. Patulin did not affect feed intake, milk production, milk composition or blood parameters. In another study, five beef wethers were dosed orally with patulin, at 3.3 up to 5 mg patulin/kg BW/day for 7 days. A decrease in dry matter intake and daily weight gain was observed. We conclude that patulin did not adversely affect lactating sheep but did adversely effect beef sheep at the doses used in this study. |
