Mycotoxin binder increases growth performance, nutrient digestibility and digestive health of finisher pigs offered wheat based diets grown under different agronomical conditions

The objective of this study was to investigate the effect of a wheat-based diet, exhibiting different levels of mycotoxin contamination and the presence of a mycotoxin binder on growth performance, nutrient digestibility and digestive health in finisher pigs. Sixty-four pigs (38.7 kg (SD 3.48 kg)) were assigned to one of four dietary treatments: (T1) low quality wheat diet, (T2) low quality wheat diet containing 2 g/kg of a mycotoxin binder, (T3) high quality wheat diet, (T4) high quality wheat diet containing 2 g/kg of a mycotoxin binder. The inclusion of wheat was 500 g/kg. The mycotoxin binder used was a Hydrated Sodium-Calcium-Aluminum-Silicate, which also included calcium propionate and calcium formate. The low quality wheat grain had a higher level of zearalenone (233.02 vs. 33.36 μg/kg), aflatoxin (4.08 vs. 2.94 μg/kg) and ochratoxin (28.20 vs. 4.23 μg/kg). Pigs offered the low quality wheat diet had a lower average daily gain (ADG) (P < 0.05), average daily feed intake (ADFI) (P < 0.001) and had a reduced coefficient of apparent total tract digestibility (CATTD) (P < 0.05) of nitrogen (N) and gross energy (GE) compared with pigs offered the high quality wheat diets. The inclusion of a mycotoxin binder improved ADG and ADFI (P < 0.05) and also increased the CATTD of N and GE compared to diets without a mycotoxin binder. Pigs offered the low quality wheat diets had increased (P < 0.05) expression of tumour necrosis factor (TNF) in the duodenum and colon and of claudin 2 (CLDN2) (P < 0.001) in the duodenum, compared to pigs offered the high quality wheat diets. Pigs offered diets containing a mycotoxin binder had increased expression of ghrelin (GHRL) (P < 0.05) in the duodenum compared to pigs offered diets without a mycotoxin binder. There was a wheat × mycotoxin binder interaction on the expression of peptide transporter 1 gene (SLC15A1/PEPT1) and sodium-glucose linked transporter 1 gene (SLC5A1/SGLT1) (P < 0.05) in the duodenum. Pigs offered the low quality wheat with a mycotoxin binder had lower expression of SLC15A1/PEPT1 and SLC5A1/SGLT1 expression compared to the low quality wheat diet only. However, there was no response to mycotoxin binder supplementation with the high quality wheat diet. In conclusion, the low quality wheat reduced ADG, ADFI, nutrient digestibility and modified the gene expression of genes involved in intestinal nutrient transport and inflammation. The supplementation of a mycotoxin binder improved ADG, ADFI, nutrient digestibility and also improved digestive health through increases in nutrient transporter and tight junction gene expression.