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Clays (hydrated aluminosilicates) are naturally occurring materials composed primarily of fine-grained minerals. Several literature reviews suggest that clays may have antibacterial or antidiarrheic effects. Therefore, the objective of these studies was to determine whether 3 different clays in the nursery diet reduce diarrhea of weaned pigs experimentally infected with a pathogenic Escherichia coli. Weaned pigs (21 d old) were housed in individual pens for 16 d [4 d before and 12 d after the first challenge (d 0)]. The treatments were in a factorial arrangement: 1) with or without an E. coli challenge (F-18 E. coli strain; 1010 cfu/3 mL oral dose daily for 3 d from d 0) and 2) dietary treatments. Growth performance was measured for each interval and diarrhea score (DS; 1 = normal; 5 = watery diarrhea) was recorded for each pig daily. Feces were collected on d 0, 3, 6, 9, and 12 and plated on blood agar to differentiate β-hemolytic coliforms (HC) from total coliforms (TC) and on MacConkey agar to verify E. coli. Their populations on blood agar were assessed visually using a score and expressed as a ratio of HC to TC scores (RHT). Blood was collected on d 0, 6, and 12 to measure total and differential white blood cell (WBC) counts.
In Exp. 1 (8 treatments; 6 replicates), 48 pigs (6.9 ± 1.0 kg of BW) and 4 diets [a nursery control diet (CON), CON + 0.3% smectite (SM), CON + 0.6% SM, and CON until d 0 and then CON + 0.3% SM] were used. The SM treatments did not affect growth rate of the pigs for the overall period. In the E. coli challenged group, the SM treatments reduced DS for the overall period (1.77 vs. 2.01; P < 0.05) and RHT on d 6 (0.60 vs. 0.87; P < 0.05) and d 9 (0.14 vs. 0.28; P = 0.083), and altered differential WBC on d 6 (neutrophils, 48 vs. 39%, P = 0.092; lymphocytes, 49 vs. 58%, P = 0.082) compared with the CON treatment. In Exp. 2 (16 treatments; 8 replicates), 128 pigs (6.7 ± 0.8 kg of BW) and 8 diets [CON and 7 clay treatments (CON + 0.3% SM, kaolinite, and zeolite individually and all possible combinations)] were used. The clay treatments did not affect growth rate of the pigs. In the E. coli challenged group, the clay treatments reduced DS for the overall period (1.63 vs. 3.00; P < 0.05), RHT on d 9 (0.32 vs. 0.76; P < 0.05) and d 12 (0.13 vs. 0.39; P = 0.094), and total WBC on d 6 (15.2 vs. 17.7 × 103/μL; P = 0.069) compared with the control treatment.
In conclusion, dietary clays alleviated diarrhea of weaned pigs.
M Song, Y Liu, JA Soares, TM Che, O Osuna, CW Maddox and JE Pettigrew, 2012. Dietary clays alleviate diarrhea of weaned pigs. Journal of Animal Science, 90: 345-360. http://dx.doi.org/10.2527/jas.2010-3662.
