High dietary zinc supplementation increases the occurrence of tetracycline and sulfonamide resistance genes in the intestine of weaned pigs

Table 1 Overall effect of dietary zinc on the occurrence of tetA and sul1 genes in pigs (n = 336)

Dietary Zn	Antibiotic resistance genes [log copy number/g sample]
Dietary Zn	tetA	sul1
Low Zn	4.78 (±0.63)^a	5.43 (±0.63)^a
Intermediate Zn	4.94 (±0.59)^a	5.50 (±0.69)^a
High Zn	5.29 (±0.60)^b	5.82 (±0.52)^b

Sampling days: 6, 13, 20 or 27 days post-weaning (26 days); intestinal sites: stomach, mid-jejunum, terminal ileum, colon ascendens
^a,bSignificantly different within a column (p ≤ 0.05; Mann–Whitney U test)

ISSN: 1757-4749