Factors Influencing Fungal Activity in Low Moisture Poultry Feeds

Abstract

Feed samples were collected from the feed mill and four growers from each of two commercial broiler companies. Two sets of samples were collected from the first, middle, and last feeders in each poultry house. Feed samples were analyzed for mean particle size, respiratory C0 2 , moisture, percent fines, and zinc concentration. A significant (P<.05) increase in fungal activity was noted as feed moved from the feed mill to the feeder pans. This increase was associated with an increase in fines and higher zinc concentrations. The data presented offer an explanation as to how fungal activity and subsequent mycotoxin production may routinely occur under field conditions.(

Research Note: Relationship of Feed Surface Area to Fungal Activity in Poultry Feeds

“…In addition, these findings reinforce previous recommendations that: 1) feed residence time in a house be minimized (Good and Hamilton, 1981); 2) houses be properly ventilated to reduce ambient relative humidity (Jones, et al 1982); and 3) feeders be allowed to empty periodically to reduce fungal activity in feed (Jones and Hamilton, 1986). In addition, these findings reinforce previous recommendations that: 1) feed residence time in a house be minimized (Good and Hamilton, 1981); 2) houses be properly ventilated to reduce ambient relative humidity (Jones, et al 1982); and 3) feeders be allowed to empty periodically to reduce fungal activity in feed (Jones and Hamilton, 1986).…”

“…Respiratory C0 2 values reported here are lower than those reported earlier (Jones and Hamilton, 1986). This may be due to the fact that feed samples were adjusted to 25% moisture in the earlier study while they were adjusted to 20% in the present study.…”

“…A previous study described the relationship between increased fines and fungal activity in feeds (Jones and Hamilton, 1986). Although fines were not measured in this study, fines caused only a two-fold difference in fungal activity in the previous study (Jones and Hamilton, 1986).…”

A Limited Survey of Aflatoxins in Poultry Feed and Feed Ingredients in Guyana

“…In Guyana, feed companies are located near the capital city and feed is transported by trucks to other parts of the country. Pressure on the feed during transport reduces the feed into smaller particle sizes, which encourages the growth of fungus [ 25 ]. In addition, exposure to high relative humidity and long periods of storage are directly related to fungal contamination.…”

Factors Influencing Antifungal Activity of Gentian Violet in Poultry Feed and Ingredients ,

“…The importance of dispersion derives from the consideration that an inhibitor must be in physical contact with the fungus before inhibition can occur. It should be recalled that fungal activity in pelleted feed increases as the level of fines increases (Jones and Hamilton, 1986). To the extent that a smaller particle size causes an increase in the level of fines in pelleted feeds (an unknown and unstudied relationship), a decrease in particle size of feeds might not improve the effectiveness of inhibitors in lowering total fungal activity.…”