Effect of zinc oxide sources and dosages on gut microbiota and integrity of weaned piglets

Abstract

Zinc oxide (ZnO) supplied at pharmacological dosage in diets of weaned piglets improves growth performance. However, it causes environmental contamination and induces bacterial antibiotic resistance, yet this practice is debated. The effects on gut microbiota and integrity in weaned piglets of conventional ZnO at nutritional and pharmacological dosage (110 and 2,400 mg/kg Zn, respectively) were compared to an alternative ZnO source at 110 and 220 mg/kg Zn. Each of the four treatments was applied to four pens (two piglets/pen; weaning age, 20 days) for 15 days, and piglets were sampled on day 15 to determine indices of gut integrity. Feeding conventional ZnO at 2,400 mg/kg Zn reduced coliforms and Escherichia coli in distal small intestine as compared to conventional ZnO at 110 mg/kg (−1.7 and −1.4 log10 cfu/g, respectively), whereas the alternative ZnO reduced only coliforms, irrespective of dosage (−1.6 to −1.7 log10 cfu/g). Transepithelial electrical resistance of distal small intestinal mucosa was higher for pigs fed the alternative ZnO source as compared with groups fed 110 mg/kg Zn of conventional ZnO, in line with a trend for higher gene expression of claudin‐1 and zona occludens‐1. Interestingly, the alternative ZnO source at 110 and 220 mg/kg Zn increased intestinal alkaline phosphatase gene transcript as compared to conventional ZnO at 110 mg/kg Zn, whereas the alternative ZnO source at 110 mg/kg Zn exhibited higher Zn concentrations in mucosa (2,520 μg/g) as compared to conventional ZnO at 110 mg/kg Zn (1,211 μg/g). However, assessing alkaline phosphatase activity, no significant effects were found. In conclusion, the alternative ZnO reduced digesta Enterobacteriaceae numbers and improved gut integrity, albeit similar or better, depending on the dosage, to the effects of pharmacological dosage of conventional ZnO.

Recent Advances in Understanding the Influence of Zinc, Copper, and Manganese on the Gastrointestinal Environment of Pigs and Poultry

“…Various studies have reported that pharmacological dietary inclusions of ZnO modify the GIT microbial community, including reductions in diversity and evenness [ 16 ], anaerobes [ 17 ], Enterobacteriaceae [ 18 ], clostridia and coliforms [ 19 ], E. coli [ 20 ], lactic acid bacteria and lactobacilli [ 21 ], and/or increases in coliforms and enterococci [ 21 ] or lactobacilli [ 19 ], evidently with opposite or contradictory effects sometimes reported. More recently, Pieper et al [ 16 ] reported higher abundances of Bacteroides , Parabacteroides , Collinsella , Acetivibrio , Blautia , Coprococcus , Faecalibacterium , Subdoligranulum and lower abundances of Megasphaera , Dialister , Acidaminococcus , and Ruminococcus in the colon of weaned pigs fed 2500 mg/kg ZnO using metagenomic sequencing.…”

Changes in Diarrhea Score, Nutrient Digestibility, Zinc Utilization, Intestinal Immune Profiles, and Fecal Microbiome in Weaned Piglets by Different Forms of Zinc

“…Collectively, ZnO is a powerful immunomodulatory nutrient for piglets, but its effectiveness seems to depend on the levels of ZnO. Zinc administration is known to induce changes in the gut microbiome; ZnO supplementation reduces the abundance of opportunistic pathogens including Campylobacterales, Enterobacteriaceae, and Escherichia, resulting in improved gut integrity [ 14 , 15 , 16 ]. Despite the recently demonstrated beneficial effects of ZnO usage, many efforts have been made to reduce its excessive use in piglets as high levels of ZnO in the diets of weaned pigs are mostly excreted, resulting in markedly high concentration of zinc in the soil [ 17 ].…”

Lactobacillus plantarum PFM 105 Promotes Intestinal Development Through Modulation of Gut Microbiota in Weaning Piglets

“…During past two decades, numerous studies have focused on the development of alternatives to antibiotics to maintain swine health and performance (Thacker, 2013; Wang J. et al, 2018). The most widely researched non-antibiotic alternatives include probiotics, prebiotics, acidifiers, and essential oils (Valeriano et al, 2016; Gresse et al, 2017; Wang W. et al, 2018). Among these alternatives, probiotics have higher potential to act as feed additives against pathogens (Gresse et al, 2017; Azad et al, 2018).…”