Nevertheless, the increase in aflatoxin excretion in
feces did not translate to reduced AFM1 carryover in
milk. The rate of carryover averaged 0.47 and 0.27% for
the short- and long-term exposures, respectively. These
values were similar to the 0.26% reported by Battacone
et al. (2005) on ewes fed a similar dose, but lower than
the 0.12% reported by the same authors using a higher
dose (Battacone et al., 2003). Carryover has been
shown to increase in high-producing cows (Veldman
et al., 1992) and the same may occur in ewes. Other
reports have also identified milk yield as the main factor
contributing to the variability of toxin excretion in
lactating animals (Masoero et al., 2007). The ewes used
in our study were in mid-lactation at the start of the
trial and may be not a good experimental model to test
the effect of mycotoxin-reducing additives on milk carryover.
We did, however, observe a reduction of AFM1
concentration in ewes fed YCW during the short-term
exposure, when carryover was almost double than that
recorded during the long-term exposure. Other studies
in dairy cows also reported the absence of effect of
YCW on milk contamination (Stroud, 2006; Kutz et
al., 2009).