Effects of reducing dietary crude protein concentration and supplementation with laminarin or zinc oxide on the faecal scores and colonic microbiota in newly weaned pigs

Abstract

A 2 × 3 factorial design experiment was conducted to examine the effects of reducing dietary crude protein (CP) concentration and/or supplementation with zinc oxide (ZnO) or laminarin on faecal scores (FS) and the large intestinal microbiota post‐weaning (PW). One hundred and forty‐four pigs were assigned to (T1) 21% standard CP diet (SCP); (T2) SCP + ZnO (SCP ZnO); (T3) SCP + laminarin (SCP LAM); (T4) 18% low CP diet (LCP); (T5) LCP + ZnO (LCP ZnO); and (T6) LCP + laminarin (LCP LAM; n = 8 replicates/treatment). The LCP diet had no effect on FS (p > .05), it increased two measures of alpha diversity, reduced Bacteroidetes and increased Enterobacteriaceae and Helicobacteraceae in the colon relative to the SCP diet (p < .05). ZnO supplementation reduced FS and increased Ruminococcaceae compared with unsupplemented pigs (p < .05). ZnO supplementation increased the genera Frisingicoccus (p < .001), Lachnoclostridium (p < .05) and Peptoclostridium (p < .05) in the colon and reduced total caecal volatile fatty acids (VFA) concentrations compared with the unsupplemented and laminarin‐supplemented pigs. Laminarin supplementation reduced FS compared with unsupplemented pigs but had no major effect on the microbiota compared with the unsupplemented pigs. There were CP concentration × additive interactions on both Firmicutes and Proteobacteria. Firmicutes were increased in the LCP ZnO group compared with the LCP group, but there was no difference between the SCP groups. Proteobacteria were reduced in the LCP ZnO group compared with the LCP and LCP LAM groups (p < .05), but there was no difference between the SCP groups. In conclusion, reducing CP did not improve FS; it increased the relative abundance of Enterobacteriaceae; however, it also increased bacterial diversity. Supplementation with ZnO and laminarin improved FS, although all groups had scores within the healthy range. ZnO altered the large intestinal microbiota and VFA concentrations; however, laminarin did not enhance these parameters, suggesting these compounds have differing modes of action.

Using Shotgun Sequencing to Describe the Changes Induced by In-Feed Zinc Oxide and Apramycin in the Microbiomes of Pigs One Week Postweaning

“…Similar to previous studies ( 28 ), overgrowth of E. coli was linked to the rise of other Proteobacteria such as D. piger in control samples, a bacteria linked to unhealthy enteric status ( 29 ) and which seems to be controlled by ZnO ( 24 ). The clear association of these and other Proteobacteria with the Ct animals clearly evidences that either both ZnO and apramycin limited their growth or that the microbiota in these treated animals exerted a competitive exclusion against these bacterial groups.…”

“…The results consistently evidenced the association of Zn treatment with species belonging to Ruminococcus , Eubacterium , Clostridium , Blautia , Lachnoclostridium ( Lachnoclostridium phocaeense exclusively in the core microbiota of the Zn group), and Roseburia , all from the order Eubacteriales (phylum Firmicutes , class Clostridia ). Previous studies support the presence of members of Lachnospiraceae in ZnO-based diets ( 23 , 24 ). Members of the class Clostridia such as those enriched in ZnO-treated animals are considered part of the desirable anaerobic microbiota, renowned fiber-degrading bacteria and short-chain fatty acid (SCFA) producers ( 30 , 31 ).…”

“…It is a bactericidal antibiotic within the group of aminoglycosides that inhibits bacterial protein synthesis by irreversibly binding to the receptor proteins on the 30S subunit of the bacterial ribosome ( 22 ). Both treatments not only directly inhibit the growth of pathogens but also modulate the piglets’ gut microbiota composition ( 23 , 24 ). However, more knowledge is needed about the precise impact of these medications on the microbiota in order to clarify which bacteria and functional roles are misplaced when these treatments are removed.…”

Intestinal microbiota modulation and improved growth in pigs with post-weaning antibiotic and ZnO supplementation but only subtle microbiota effects with Bacillus altitudinis

“…In agreement with these findings, faecal and intestinal microbial diversity was also reduced when PW diets were supplemented with pharmacological levels of ZnO, alone or in combination with antibiotics in previous studies 46 – 48 , although sometimes it was unaffected 35 , 49 , 50 . Conversely, it has also been reported that high doses of ZnO can even increase α-diversity index values 51 , 52 .…”

Characteristics of the gut microbiota in Bifidobacterium catenulatum LI10 pretreated rats with lower levels of D-galactosamine-induced liver damage

“…Some other phylotypes assigned to Frisingicoccus , Muribaculaceae, Romboutsia and Turicibacter were determined as representative ASVs to Non‐Severe cohort but not Severe cohort. Frisingicoccus was increased in the colon of pigs treated with zinc oxide supplementation (Rattigan et al, 2020). Muribaculaceae has been regarded as a beneficial bacterium due to its promotion effect on gut metabolism (Ma, Zhou, et al, 2020).…”