*3.1. Phytochemicals*

The phytochemical substances in the SFPs consisted of 32.56 g/kg DM flavonoids, 4.68 g/kg DM phenolics, and 0.37 g/kg DM others (glycosides, hydroxy fatty acids, and a derivative of cinnamic acid, Table 2).



1 Trihydroxy-6-[4-(3-oxobutyl)phenoxy]oxane-2-carboxylic acid; 2 2-(3-Methoxy-4-hydroxyphenyl)-5-hydroxy-7-[2-*O*-(beta-D-glucopyranuronosyl)-beta-D-glucopyranosyloxy]-4H-1-benzopyran-4-one; 3 Kaempferol 3-*O*glucoside-7-rhamnoside.

#### *3.2. Ruminal Fermentation In Vitro*

Methane concentration was significantly lower (*p* = 0.046), but IVDMD (*p* < 0.001), total VFA concentration (*p* = 0.011), and *n*-valerate concentration (*p* = 0.017) were significantly higher, in the SFP than the control group (Table 3). *Archaea* and *Methanomicrobiales* populations were smaller in the SFP than the control group (*p* < 0.001 and *p* = 0.009, respectively).

**Table 3.** Effect of SFPs on ruminal fermentation and microbial populations in vitro.




IVDMD, in vitro dry matter digestibility; VFAs, volatile fatty acids.

#### *3.3. Ruminal Fermentation and Microbiota in the Lambs*

The SFPs significantly affected (*p* = 0.030) methane concentrations in the lambs (Table 4). Total protozoa, expressed as a count per gram of wet RC (wRC) in the lambs, did not differ significantly (*p* = 0.05) between the groups. The populations of *Archaea* (*p* < 0.001), *Methanomicrobiales* (*p* = 0.009), and *Methanobacteriales* (*p* < 0.001) were significantly smaller for the SFP than the control group. The relative abundances of *S. bovis, B. proteoclasticus*, *F. succinogenes*, *M. elsdenii*, *R. albus*, *R. flavefaciens*, and the genera *Prevotella* and *Lactobacillus* did not differ significantly between the groups (*p* = 0.05). The relative abundance of *B. fibrisolvens* was significantly higher in the SFP than in the control group (*p* = 0.006). The relative abundance of the 16S rRNA gene was expressed as an arbitrary unit (AU) relative to the total abundance of bacterial genes of the control group.


wRC, count per gram of wet ruminal content; AU, arbitrary unit.
