Effects of Dietary Natural Mycotoxins Exposure on Performance, Biochemical Parameters and Milk Small Molecule Metabolic Pathways of Lactating Cows

The presence of mycotoxins in feed has the potential to cause significant detriment to animal and human health, and even severe economic implications. Previous studies on the effects of mycotoxins mainly focused on the addition of commercially available mycotoxins into feeds in animals. In the present study, corn meal and cottonseed were kept in warm and humid conditions to allow for mycotoxins produced and then used to substitute 50% and 100% of normal corn meal and cottonseed in diets for lactating cows for 14 days. The results showed that aflatoxin M1, deoxynivalenol, aflatoxin B1, and zearalenone were primary mycotoxins in milk from cows fed the diets. Compared with the control group, feeding the diets containing mildewy corn meal and cottonseed reduced feed intake, milk yield, and milk fat, protein and lactose productions (<i>p</i> > 0.05). No significant difference was observed in the acetate and valerate concentrations, acetate to propionate ratio, and the calculated CH₄ production in rumen fluid (<i>p</i> > 0.05), whereas, the propionate, butyrate, isovalerate concentrations were affected (<i>p</i> < 0.05) depending on the content and type of natural mycotoxins. Serum creatinine and total glyceride concentrations were influenced with corn meal and cottonseed fully replaced with the mildewy feeds. Metabolic pathways for small molecule metabolites in milk were altered by dietary mycotoxin exposures, and the changes were mainly associated with amino acid metabolism, glucose metabolism, and energy metabolism. However, cows exposed to natural mycotoxins in the diets were still in healthy conditions and had low somatic cell count in milk.