THE EFFECT OF ARTIFICIAL INOCULATION WITH SELECTED FUSARIUM STRAINS ON NUTRITIONAL QUALITY AN ENSILING PROCESS OF BT MAIZE
2010, 11 (3) p. 279-284
The objective of the study was to compare the nutritive value and mycotoxin content of maize forage and silage of near isogenic control MONUMENTAL (C) and Bt maize (MONSANTO, MON 810) that was either untreated (Bt) or artificially inoculated with Fusarium strains (I-Bt). The inoculation was made in the growing crop in milk stage of maturity. Plants were harvested at the soft dough stage of maturity and ensiled in microsilage tubes. The content of forage dry matter (DM) was 307.6 g/kg in C, 306.9 g/kg in Bt and 298.0 g/kg in I-Bt. All forages were positive for deoxynivalenol, aflatoxin, fumonisins and zearalenone (P>0.05). Content of DM was the lowest in I-Bt silage (285.5 g/kg) and differed significantly from C (296.7 g/kg) or Bt (303.7 g/kg, P<0.05). Content of crude protein (CP) was the lowest in I-Bt silage (79.0 g/kg) and differed significantly from C or Bt (85.7 or 81.9 g/kg, respectively, P<0.05). Silages Bt and I-Bt had lower pH (3.93 and 3.96, respectively) than silage C (4.02, P<0.05). Silage I-Bt tended to have a higher degree of proteolysis 9.18 %) measured as N-NH3 (% of total N) than silages C or Bt (8.64 or 8.9 %, respectively, P>0.05). Lactic acid was predominant product of fermentation in all silages, however silage I-Bt tended to have lower content of lactic acid (20.96 g/kg) than C or Bt (24.76 or 23.82 g/kg, P>0.05). I-Bt silage contained lower levels of eoxynivalenol (602 ppb) than C or Bt silage (748 and 690 ppb, respectively, P<0.05). Content of fumonisins and zearalenone in C did not differ from I-Bt (P<0.05) but both were lower than in Bt (P<0.05). In conclusion, nutritional value a fermentation parameters of Bt silage were similar to C except of CP content and pH that was lower in Bt (P<0.05). I-Bt silage had lower content of DM, CP and fat than Bt silage (P<0.05). Controversially, concentrations of mycotoxins in I-Bt silage were lower than in Bt.