Post-weaning diarrhoea (PWD) is an infectious disease that causes significant productive and economic losses in pig industry. It often requires antimicrobial use, resulting in the risk of antimicrobial resistance. Zinc oxide (ZnO) used in a range of 1500-3000 ppm is also an effective treatment to prevent PWD. However, the high dose of ZnO was banned in the EU in 2022 due to environmental risk of soil pollution. Some protective ZnO could reduce the effective dosage to 1000 ppm, but it still can not meet the EU’s requirements.
The main causative agent of PWD is enterotoxigenic Escherichia coli (ETEC) and the high dose of ZnO is effectively controlling ETEC overgrowth during the postweaning period. Although the exact mechanism of action of the high dose of ZnO is not completely understood, it is generally accepted that the high dose of ZnO could stabilize the gut microbiome to avoid its dysbiosis.
It is clear now that bile acids and bile salt hydrolase (BSH) are fundamental to maintaining the stability and composition of the gut microbiota. Bile acids have direct antimicrobial effect (Figure 1) and also act as signalling molecules to increase the production of antimicrobial peptides. However, when bile acids are hydrolysed by BSH, their antimicrobial activity is significantly reduced. Antibiotics and the high dose of ZnO usually suppress this BSH activity to allow bile acids to remain active longer and control pathogens.
Figure 1. The effect of conjugated bile acids on the growth of some pathogens
Gutluk is developed by CJ Bio via machine learning technology to screen key ingredients as BSH inhibitors (BSHI). The optimal combination of Epicatechins+VitaminK+Tributyrin achieved the best result on anti-inflammation effects (Figure 2). Thus, Gutluk could be an alternative to prevent PWD while antibiotics and the high dose of ZnO were removed in weaned piglet diets. A recent 28 day trial conducted in Korea confirmed this.
The standard, negative control diet was formulated without antibiotics and the high dose of ZnO (NC). The second and the third treatment consisted of the NC supplemented with 0.2% Colistin (antibiotics, PC1) and 2000 ppm ZnO (PC2), respectively. Other three treatments consisted of NC supplemented with 0.05%, 0.1% and 0.2% GutlukTM, respectively.
Figure 2. The effect of Gutluk composition on anti-inflammation function.
Weaned piglets fed diets without antibiotics and the high dose of ZnO showed poor growth rate (Figure 3)and significantly high rate of diarrhea (Figure 4). There was no significant difference among Gutluk supplementation groups but adding 0.2% Gutluk treatment achieved the best result, comparable to the high dose of ZnO treatment.
Figure 3. The effect of supplemental Gutluk on piglets growth performance (g/d)
Figure 4. The effect of supplemental Gutluk on piglets diarrhea rate (%)