297 Less Plasma, same growth performance? Sugar cane yeast extract as an animal-free protein source alternative in weaned piglet diets.

Abstract Minimizing the effects of post-weaning stress on growth performance while preserving piglets’ intestinal health status is the main target at the beginning of the nursery phase. Thereby, pre-starter diets contain high-quality ingredients, such as spray-dried plasma (SDP), to stimulate consumption and improve digestibility and immune system function. Although SBP has high palatability, digestible proteins, and immunoglobulins, its high cost often limits the use of higher levels or even inclusion in the diet. A potential SBP partial replacement is Saccharomyces cerevisiae yeast extract (YE), rich in peptides, amino acids, especially glutamic acid, and nucleotides, which are important for the energy, repair, and development of fast-growing tissues. Therefore, this study aimed to evaluate the YE dietary inclusion, replacing SBP, on the performance and intestinal health and microbiome of early-weaned piglets. Weaned piglets (n = 350; 5 pigs/pen) were blocked according to body weight and sex and randomly assigned to one of the five dietary treatments: a control diet with 3% and 1.5% SDP (respectively in pre-starter I and II diets; CN), a CN and 1% YE on top diet (CN+1%YE on top), 16,7%YE in SDP replacement (0,5%YE), 33.3%YE in SDP replacement (1%YE), or 50%YE in SDP replacement (1,5%YE). Meanwhile, no SDP or YE was applied to starter diets (I and II). Feed intake by pen was recorded daily, whereas individual body weight was registered weekly. At d21, fecal samples from 10 piglets/treatment were also selected for microbiome profile and myeloperoxidase analysis. The performance data were analyzed using ANOVA and Tukey’s test. The Mann-Whitney non-parametric test performed the alpha diversity between groups, while beta diversity analysis was conducted using perMANOVA within the QIIME2 pipeline. The myeloperoxidase data was analyzed using the Kruskal-Wallis and Dunn’s post hoc tests. For all tests, differences were considered significant when P< 0.05. The CN had a higher feed intake than 1,50%YE in the pre-starter I phase (Table 1; P< 0.05), which may be related to the high glutamic acid presence in 1,5%YE compared to CN, which may have influenced piglets’ palatability. Despite the reduced feed intake, no difference in weight gain, body weight, and feed conversion was observed (P >0.05). Additionally, no further differences in performance were noticed in the subsequent feeding phases between treatments (P >0.05). At d 21, there were no changes in microbiome alpha (Figure 1; P >0.05) and beta diversity (Figure 2; P >0.05), as well as no differences in myeloperoxidase fecal concentrations (Figure 3, P >0.05). This indicates that YE may contribute to gut health without changes in the inflammatory status and maintaining a stable microbiota in the gastrointestinal tract. Accordingly, YE may be a partial SBP substitute in diets for weaned pigs, maintaining performance without negatively impacting gut health and microbiome.