Abstract There is increased interest in supplementing the diets of weaned pigs with yeasts and yeast-derived additives due to data demonstrating improved animal health and performance metrics. MicroGold MC® (MG) is a concentrated brewers yeast supplement derived from a unique strain of Saccharomyces cerevisiae. A randomized complete block design study was used to evaluate three different concentrated brewers yeast (BY) products on nursery pig performance. A total of 1, 260 weanling pigs housed in mixed sex pens of 21 (15 replicate pens) were allotted to the following treatments: Control (no additive), BY1 (1. 13 kg/ton), BY2 (0. 45 kg/ton), or MG (0. 45 kg/ton). The study was carried out from weaning (approximately 21 d of age and 5. 6 ± 0. 01 kg) to 42 days. The commercially representative diets were a crumble/meal blend in Phases 1 and 2, and meal form in Phase 3, and did not contain antibiotics. Diets were formulated to meet or exceed NRC (2012) recommendations and contained pharmacological zinc (Phases 1 and 2) and copper (Phase 3). Phase 1 diets were fed days 0 to 8, Phase 2 diets were fed days 8 to 21, and Phase 3 diets were fed days 21 to 42. Pigs had ad libitum access to feed and water throughout the study. Pen weights (BW) and feeder weights were measured at the end of each dietary phase to calculate ADG, ADFI, and FCR. Performance variables for each study phase, and across phases, were analyzed using a linear mixed model analysis in R (v 4. 2. 1 by using JASP 0. 16. 4) software. The linear mixed model used a fixed effect of treatment group and a random effect of block. Economic variables were analyzed using a similar model. There were no effects of dietary yeast treatment on ADG, ADFI, average BW, or pen weight gain over the course of the study, compared to the control. There was a significant effect (P = 0. 003) of dietary treatment on overall FCR where it was decreased (i. e. , improved; P ≤ 0. 05) in pigs fed the MG treatment (1. 323) compared with pigs fed the control (1. 358) or BY1 (1. 368) treatments. There was no difference in overall FCR between MG (1. 323) and BY2 (1. 343) treatments. Additionally, there were no differences in mortality across treatment groups. Economic analysis revealed that feeding MG reduced (P 0. 05) feed cost/kg. gain by 0. 022 per head. The income over feed cost per pig placed was increased (P = 0. 10) by 0. 50 during the study. The results of this study suggest that feeding nursery pigs MicroGold MC can improve feed efficiency, reduce feed cost, and thereby increase revenue during the nursery period.
Cole et al. (Wed,) studied this question.