1744 Effects of different sources and routes of administration of copper and vitamins A and D on piglets gut microbiota

Placental and colostral transfers of copper and vitamins A and D micronutrients from dams to neonates are limited in pig species (Matte et al., 2014, JAS 92-Suppl. 2:153). The aim of the study was to evaluate the influence of different perinatal micronutrient supplementation strategies on piglets' gut microbiota. Within each litter from 5 sows, 10 newborn piglets were allocated to one of the following combinations of sources and routes of micronutrient administrations: oral vitamin D3, retinol-acetate and CuSO4 (T1); oral 25-OH-vitamin D3, β-carotene and Cu-yeast (T2); exposure to UVB light (20 min every second day), oral retinol-palmitate and Cu-gluconate (T3); intramuscular vitamin D3 and retinol-propionate and oral Cu-acetate (T4); oral saline (CTL). Oral or intramuscular provisions corresponded to 12 mg of copper and 70 and 12 MIU of vitamins A and D, respectively. This design was repeated with 5 other sows fed daily extra supplements of 25-OH-vitamin D3 (4 MIU), β-carotene (24 MIU) and Cu-yeast (45 mg) from 90 d of gestation to 21 d of lactation. At 21 d of age, feces were collected and piglets were weaned. At 23 d of age, 5 repetitions of a combination of sow and piglet factorial treatments were sacrificed and feces and content from mid-jejunum, ileum, mid-colon, and rectum were collected to characterize gut microbiota. Bacterial communities were analyzed by sequencing the V3-V4 regions of 16S rRNA genes on an Illumina MiSeq. Bioinformatic analyses were performed on our internal data analysis pipeline and statistics were performed in R. The analysis of bacterial community composition at the class level revealed that sow supplementation significantly increased the relative abundance of Bacilli in feces at d 21 (P = 0.04) but not at d 23. Gut microbiota diversity significantly differed (P = 0.03) according to supplemental treatments provided to piglets. However there was no piglet treatment effect on gut microbiota based on PCoA analyses. The Shannon diversity of jejunal and ileal microbiota was significantly (P < 0.05) decreased when supplementation was given to sows. Sow supplementation also significantly increased Bacilli in both jejunum and ileum (P < 0.001, both). The study demonstrated that piglet gut microbiota can be modulated by daily extra supplementation of vitamins A and D and organic copper to sows during late pregnancy and lactation periods. Further studies are thus warranted to study mechanisms of action explaining the impact of such maternal micronutrient supplementation on bacterial colonization in piglets gut.