Abstract #M24

# M24
Aluminosilicate clay reduces the deleterious effects of an aflatoxin challenge on performance in lactating Holstein cows.
Russell T. Pate*1, Devan M. Paulus Compart2, Felipe C. Cardoso1, 1Department of Animal Sciences, University of Illinois, Urbana, IL, 2PMI Nutritional Additives, Shoreview, MN.

Adsorbent use in aflatoxin (AF) contaminated diets is critical in alleviating detrimental effects of AF on dairy cattle performance. The objective of this study was to determine the effects of a commercially available aluminosilicate clay in a traditional lactation diet during an AF challenge on the presence of AF in milk, urine, and feces, and performance parameters of multiparous lactating Holstein cows. Sixteen multiparous, lactating, Holstein cows [BW (mean ± SD) = 758 ± 76 kg; DIM = 157 ± 43 d] were assigned to 1 of 4 treatments in a replicated 4 × 4 Latin Square design: no adsorbent and no AF challenge (CON), no adsorbent and AF challenge (POS), 113 g of aluminosilicate clay top-dressed on TMR (adsorbent; PMI Nutritional Additives, Arden Hills, MN) with AF challenge (F4), and 227 g of adsorbent with AF challenge (F8). For each period, milk was sampled 3 times daily from d 14 to 21, while feces and urine were sampled on d 14, 18, and 21. Statistical analysis was preformed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Fat-corrected milk (POS = 37.2, F4 = 39.2, F8 = 38.9 kg/d) and ECM (POS = 37.3, F4 = 39.3, F8 = 38.9 kg/d) increased (P = 0.05 and 0.04, respectively) as concentration of adsorbent in the diet increased. Lactose yield (kg/d) increased as concentration of adsorbent in the diet increased (POS = 1.67, F4 = 1.89, F8 = 1.74 kg/d; P = 0.05). A quadratic treatment effect was present for protein yield (POS = 1.20, F4 = 1.28, F8 = 1.24 kg/d; P = 0.01). There was a decrease in milk AFM1 concentration (POS = 0.33, F4 = 0.32, F8 = 0.27 µg/kg; P = 0.001) as concentration of adsorbent in the diet increased. A quadratic treatment effect was present for AFM1 transference (POS = 0.45, F4 = 0.49, F8 = 0.39%; P = 0.03). There was a decrease for AFM1 concentration in urine (POS = 2.10, F4 = 1.89, F8 = 1.78 µg/kg; P = 0.04) and feces (POS = 4.68, F4 = 3.44, F8 = 3.17 µg/kg; P = 0.05) as concentration of adsorbent in the diet increased. In conclusion, the adsorbent used in this study had a positive effect on milk production, milk components, and AF excretion in milk, urine, and feces.

Key Words: aflatoxin, urine, adsorbent