Effects of feeding corn naturally contaminated with Fusarium mycotoxins and/or a modified yeast cell wall extract on the performance, immunity and carcass characteristics of grain-fed veal calves

Thirty-two grain-fed veal calves (177±6.7kg body weight (BW)) were used in a completely randomized block design experiment to determine effects of feeding corn diets naturally contaminated with Fusarium mycotoxins and/or a modified yeast cell wall extract (YCW) on performance, immunity and carcass characteristics. Calves were fed one of four dietary treatments in individual pens for at least 84 days either: (1) control corn+supplemental pellet (CC), (2) control corn+YCW supplemental pellet (CY), (3) mycotoxin contaminated corn+supplemental pellet (MC), and (4) mycotoxin contaminated corn+YCW supplemental pellet (MY). Diets consisted of 750g/kg whole corn grain and 250g/kg supplemental pellet with corn as the source of food-borne mycotoxins. The major contaminants present in the contaminated diets (average concentrations of MC and MY) were deoxynivalenol (DON; 10.27mg/kg), 15-acetyl DON (1.27mg/kg) and zearalenone (1.84mg/kg). Final BW and total BW gain of the calves were not different between treatment groups. However, ADG tended (P=0.07) to be higher and F:G was decreased (P=0.003) in calves fed contaminated diets. Haptoglobin, fibrinogen and IgA concentrations did not differ between treatments. Concentrations of IgG were lower (P=0.003) in calves receiving YCW. Plasma urea N and glucose concentrations were increased (P<0.001) and decreased (P=0.004), respectively, in calves fed contaminated diets. The weights (g and g/kg BW) of the liver, kidney, heart and lungs did not differ between treatments. Hot carcass weight, dressing yield, back fat, longissimus muscle area and colour Minolta L*value were also not different between treatments. These data indicate that veal calves are able to tolerate a moderate feeding level of corn grains naturally contaminated with Fusarium mycotoxins and that small improvements in F:G occurred. As there were generally no negative effects of dietary mycotoxin on performance, the efficacy of YCW as a mycotoxin adsorbent could not be assessed, but YCW alone had minimal effects on performance.