PSIII-14 Effect of Water Delivery System on Intestinal Microbial Populations of Nursery Pigs

Abstract

Abstract A previous experiment was conducted to determine if cleanliness of a water delivery system influenced growth performance of nursery pigs. Additionally, we hypothesized that cleanliness of the water delivery system would alter populations of intestinal bacteria. Newly weaned pigs (n = 315; about 21 d of age) were used in a 42-d experiment and were assigned randomly to 1 of 2 water line treatments with 17 to 18 pens/treatment and 9 pigs/pen. Treatments consisted of water delivered to pens via a water distribution system in use for 21 years without cleaning (OLD) or water delivered to pens via a water distribution system in use for 6 weeks (NEW). Water for both distribution systems was sourced from a common well. Pigs were housed in an environmentally controlled, power-ventilated, confinement nursery barn and were allowed ad libitum access to water and common diets fed in 3 phases across OLD and NEW treatments. Twenty-eight pigs of average body weight (n = 14 pigs/treatment) were selected for collection of fecal swabs on days 0, 4, and 42 post-weaning. A pooled water sample was collected from 10 randomly selected pens/treatment and from the water supply on days 4 and 42. Swabs were also collected from the inside surface of each water line at the beginning and end of each line. To characterize the microbiome in all samples, extracted DNA was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 and various packages within the R statistical software. Bacterial community composition of water and water line samples differed between OLD and NEW, while the sampling location of line swabs differed by location (PERMANOVA, R2 = 0.2-0.6, P < 0.05). No differences in alpha diversity were observed in pig fecal bacteria at d 0 or d 42 between OLD and NEW line. However, at d 4, pigs drinking water from the NEW line had increased fecal bacterial richness (P = 0.044) and a tendency for increased bacterial diversity (Shannon’s H, P = 0.059) compared with pigs drinking water from the OLD line. There were no differences in bacterial community composition between the OLD and NEW line throughout the trial; however, pigs drinking water from the NEW line showed more discriminating bacterial taxa compared with OLD at day 4 and 42, including greater abundances of Prevotella, Christensenellaceae R7, Rosburia and Bacteroides, among others (P < 0.05). In conclusion, drinking water from either water line did not have major effects on the gut microbiome of pigs, except for more fecal bacterial diversity in pigs drinking water from the new water line at day 4 post-weaning.