The effect of feedborne Fusarium mycotoxins on dry matter intake, milk production and blood metabolites of early lactation dairy cows

Fusarium mycotoxins (FM) contaminate cereals and corn and may negatively impact dairy cow performance by affecting dry matter intake (DMI) and milk production. Therefore, the objective of this study was to investigate the effect of naturally contaminated feedborne FM on DMI, milk production, BCS and blood metabolites of early lactation dairy cows. Twenty-eight Holstein Friesian cows were allocated to one of two dietary treatments (n = 14) in a randomised complete block design. Diets were offered as a total mixed ration (TMR) [concentrate (corn grain, soya and rapeseed meal), straw, grass silage and corn silage]. Treatment one (Low FM) contained corn grain with low FM levels [deoxynivalenol (DON) 163 μg DON/kg TMR DM and zearalenone (ZON) 19 μg ZON/kg TMR DM] and Treatment two (High FM) contained corn grain with higher FM levels (1966 μg DON/kg TMR DM and 366 μg ZON/kg DM). Cows were blocked on calving date and balanced for parity, predicted milk yield and body condition score. Cows started the trial 28 d post calving with a 10 d dietary acclimatisation period followed by a 28 d experimental period. There was no statistically significant difference in DMI (Low FM = 20.97 kg DM vs High FM = 20.52 kg DM, P = 0.64), milk yield (Low FM = 37.49 kgs vs High FM = 36.75 kgs, P = 0.38) or milk fat and protein kgs (Low FM = 2.61 kg vs High FM = 2.59 kg, P = 0.47) between treatments. However, cows on High FM consumed 0.45 kg DM/d less and produced 0.74 kg/d less milk. In conclusion, at the level of FM contamination reported in this study offered over a 28 d period, there was no significant effect on DMI, milk production or composition of early lactation dairy cows. However, the 0.74 kg/cow/d decline in milk yield due to feeding a FM contaminated ration can represent a significant reduction in farm gate income.