Document Type

Thesis - Open Access

Award Date

2023

Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Crystal Levesque

Abstract

Litter size and the resulting nutritional demand on the sow continue to increase while sow mortality and culling rate are also increasing. Non-nutritive feed additives may enhance sow health and thereby improve offspring growth and productivity after weaning. Development of the gut microbiome in piglets via microbial succession is critical for maximizing their productivity and providing stability for overcoming weaning stress. The objective of this study was to evaluate the impact of yeast-based postbiotic supplementation in gestation and lactation diets on offspring performance through the nursery period and on whether a yeast postbiotic could impact the sow fecal microbiome as well as affect microbial succession in piglets. Fifty-three gestating sows (parity 0 to 5; BW=242.7 ± 7.1 kg) in 2 breeding groups were blocked by parity and assigned to either a control (CON) diet or a diet supplemented with a yeast-based postbiotic (SUP) at 0.5% in gestation from d80 to 113 of gestation and 0.2% in lactation (d114 of gestation to weaning at 20 ± 2 d). Sow reproductive performance and offspring growth from birth to 65 d of age were monitored. At weaning, pigs were allotted to pens within maternal dietary treatment (10 pigs/pen; 31 to 32 pens/maternal treatment; 630 total pigs; BW=6.18 ± 0.86 kg) and all piglets received common nursery diets in a 4-phase program. Pigs were weighed at week 1, 2, 4, and 6 after weaning. Fecal bacterial composition was determined for 12 sows/treatment at d85 gestation, d1 lactation, and weaning and 1 piglet/sow at weaning and d7, 14, and 28 post-wean using Illumina MiSeq 2X300 sequencing of PCR-amplicons generated from the V1-V3 regions of the 16S rRNA gene. A comparative analysis of the most highly represented Operational Taxonomic Units (OTU) was performed using the non-parametric Kruskal-Wallis sum-rank test and Wilcoxon pairwise test. Sow body weight and reproductive performance (piglets born alive/litter, 14.4 vs 14.1; piglet birth weight, 1.45 vs 1.48 kg; piglets weaned/litter, 13.0 vs 12.9; lactation sow feed intake, 6.4 vs 6.8 kg/d) was similar in CON and SUP sows, respectively. In the first week after weaning, pigs from SUP sows had a reduced tendency to lose weight (5.6 vs 11.0%). The numerically improved feed intake in the first week after weaning may explain the lower fallback rate in pigs from SUP sows. Across both sow groups, by 65 d of age, body weight (21.53 vs 21.76 kg), average daily gain (0.36 vs 0.37 kg/day), average daily feed intake (0.54 vs 0.53 kg/day), gain efficiency (0.67 vs 0.69 kg), and mortality (1.26 vs 1.60%) was similar in piglets from CON and SUP sows, respectively. In the initial fecal microbiome comparative analysis, no significant differences between sows which received CON or SUP diets or piglets were observed (P > 0.05), although, fluctuations in the abundance of specific OTUs were found over time in both sows and piglets. For instance, the abundance of OTU JK_30-00008, predicted to be a strain of Lactobacillus amylovorous, was elevated in sows at d85 (CON: 9.01%; SUP: 12.04%), dramatically reduced at d1 of lactation (CON: 1.00%; SUP: 3.03%), then recovered by weaning (CON: 9.41%; SUP: 9.74%). In contrast, the abundance of OTU JK_16-00021, predicted to be an uncultured Peptostreptococcaceae, remained elevated in sow fecal samples from both treatment groups at d85, d1 lactation, and weaning (CON: 10.6%, 15.05%, and 15.61%; SUP: 8.98%, 13.65%, and 14.47% respectively). In piglet fecal samples, the most abundant OTUs at weaning, d7, d14, and d28 were: JK_45-00042 (CON: 27.26%; SUP: 20.05%; no affiliation to any currently defined phylum), JK_137-00038 (CON: 11.04%; SUP: 5.76%; unclassified Yersiniaceae), JK_30-00008 (CON: 13.64%; SUP: 14.11%; Lactobacillus amylovorous), and JK_51-00117 (CON: 7.66%; SUP: 5.32%; Prevotella copri), respectively. In piglets, the number of OTUs representing 50% of total sequence relative abundance increased with time (n = 5 OTUs at weaning, n = 18 at d7, n = 17 at d14, and n = 43 at d28) suggesting an increase in diversity with age. Yeast postbiotic in sow diet had limited impact on relative proportions of sow fecal microbiome and offspring microbial succession after weaning with greater piglet diversity expected due to dietary changes. In addition, several of the OTUs in greatest relative abundance in piglets, including JK_45-00042, JK_137-00038, JK_-42, and JK_-49 did not correspond to valid bacterial species. Together, these results underscore the need to identify prevalent unknown bacterial species in microbial community compositional shifts in the period around weaning.

Publisher

South Dakota State University

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Rights Statement

In Copyright