Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/26/2003
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Dairy cattle fed mycotoxin contaminated forages can experience many different performance problems. Fusarium (FUS) molds can invade forages in the field up to feeding by producing the mycotoxins zearalenone and vomitoxin. Chloride (Cl) fertilization is reported to increase plant disease resistance. To evaluate if Cl fertilization of corn could reduce mycotoxin concentrations in silage, 4 application rates of Cl (0, 56, 112, and 224 kg/ha) and 2 FUS challenge rates (non-inoculated versus inoculated) were arranged in a 4 by 2 factorial design. Three blocks of 8 treatments were randomly assigned to plot sizes of 4.6 m2 with buffer zones of 1.5 m. The corn variety was SyngentaR N48V8 planted at the rate of 12,141 kernels/ha. Potassium chloride was applied within 3 d of planting, while FUS challenge was accomplished by inserting non-cultured and cultured (Fusarium graminearum) toothpicks into ears at mid-silk and the corn plants were harvested for silage 30 d later. Corn plants were harvested by hand, chopped, and silage packed into sealed mini silos. Silos were stored for 60 d and then subjected to nutrient and mycotoxin analyses. Chloride fertilization resulted in a significant (P<.01) linear increase in Cl concentrations of corn silage (.20, .30, .38, and .52% DM, respectively for 0, 56, 112, 224 kg Cl/ha). An interaction of Cl x FUS was detected (P < .02) for zearalenone, but the interaction was nonsignificant (P>.10) for vomitoxin. When corn was inoculated with FUS, zearalenone concentrations (303, 237, 75, and 106 ppb) were greatest for 0 kg/ha Cl and lowest for 112 kg/ha Cl (P<.05). The main effect of Cl demonstrated greater (P<.05) vomitoxin concentrations (3.66, 5.11, 1.78, and 3.41 ppm) for 56 than 112 kg/ha with other Cl rates being intermediate. Fusarium molds have high protease, amylase, and cellulose activities which resulted in greater (P<.05) digestibility of NDF (52.6 and 55.0%) and DM (65.9 and 66.9%) compared to no inoculation. Application of Cl to corn can increase corn silage Cl concentrations. Higher Cl concentrations improved disease resistance of corn, which resulted in lower zearalenone and vomitoxin concentrations in the silage. The influence of mycotoxins on dairy cattle performance could be reduced by greater application rates of Cl to crops grown for forage.