Calcium Propionate Supplementation Mitigated Adverse Effects of Incubation Temperature Shift on In Vitro Fermentation by Modulating Microbial Composition

Abstract

The ingestion of cold water in winter results in fluctuating decreases in rumen temperature, impacting rumen fermentation function and methane production. This study aimed to investigate the impact of calcium propionate (CaP) on rumen fermentation characteristics, methane production, and microbial microbiome under different in vitro incubation temperatures. A 2 × 2 factorial experiment was conducted over 72 h, with or without 2.5% CaP (dry matter [DM] basis) in substrate under a constant incubation temperature (39 °C, CIT) or shifting incubation temperatures (12 cycles in total, with each cycle consisting of 4 h of incubation at 39 °C followed by immediate transfer to 30 °C for 2 h, ITS). The results showed that ITS inhibited the gas production, methane production, and methane concentration at 12 and 72 h (p p p Bacteroides (p Methanomicrobiales decreased and was positively correlated with methane production at 72 h (r = 0.47, p Prevotella_UCG_003 (p p < 0.05). Overall, our study suggests that the addition of 2.5% CaP can alleviate the adverse effects of ITS on in vitro fermentation parameters by regulating microbial composition and sustaining a reduction in methane production.

Keywords

• in vitro fermentation
• incubation temperature
• calcium propionate
• microbial abundance
• methane production