Supplementation of Sodium Bentonite Clay Did Not Alleviate the Negative Effect of Fumonisin B1 Contaminated Corn on Feed Preference and Nutrient Digestibility in Weanling Pigs

Two experiments were performed to evaluate effects of corn naturally contaminated with fumonisin B₁ (FB₁ corn, containing 73 ppm fumonisin B₁ and 0.07 ppm aflatoxin B₁) on feed preference and apparent total tract digestibility (ATTD) of nutrients in piglets and possible alleviating effects of sodium bentonite clay supplementation. Four dietary treatments were used: PC - positive control using clean corn, NC - negative control using 40% FB₁ corn, PCC - PC with 0.50% sodium bentonite clay, and NCC - NC with 0.50% sodium bentonite clay. Experiment 1 used 36 crossbred pigs (18 barrows, 18 gilts; 10.49 ± 1.09 kg) for a preference evaluation. Three dietary comparisons were made: PC vs NC, PC vs NCC, and NC vs NCC. Each comparison involved 3 pens, each with 4 pigs (2 barrows and 2 gilts). Two feeders were placed in each pen and their positions changed 3 times a week for 2 weeks. Preference was shown for PC diet over NC diet (84.1 vs 15.9%, P = 0.0003) and NCC diet (92.7 vs 7.3%, P < 0.0001), as well as for NC diet over NCC diet (75.6 vs 24.4%, P < 0.05). Experiment 2 used 24 crossbred pigs (12 barrows, 12 gilts; 8.09 ± 1.13 kg) to detect effects of contaminated corn and sodium bentonite clay supplementation on performance and ATTD in piglets. Pigs were fed a common nursery diet for 7 days before being placed in stainless steel metabolism pens with 2 pigs each (1 barrow and 1 gilt) for 19 days. There were three collection periods (7, 7, and 5 d). Pigs and feeders were weighed at the beginning and end of each period with 0.5% indigo carmine used as a visual marker of the start/end point of each collection period. There was no effect of clay inclusion, or interaction, observed on the digestibility measures (P > 0.10). For the entire 19-d period, inclusion of 40% FB₁ corn increased time of passage (26.2 vs 21.7 hr, P = 0.01), reduced daily DM intake (0.83 vs 0.91 kg/d, P < 0.05), and ATTD of DM (87.3 vs 88.9%, P = 0.02), energy, (87.3 vs 88.7, P = 0.07), and N (83.8 vs 86.8%, P = 0.01). With this combination of mycotoxins, the adverse effects observed on feed intake were of a greater magnitude than the adverse effects on ATTD. Clay addition to the diet had no positive benefit on any response measures.