Tannin-rich strawberry vines fermented with lactic acid bacteria improve growth performance in Hu sheep.

Abstract

BACKGROUND: Strawberry vines are nutrient-rich but contain high levels of tannins and have a moisture content of up to 70%, making ensiling a crucial strategy for preserving their nutritional value. METHODS: Two lactic acid bacteria (LAB) strains, designated Z and R, were isolated from strawberry vines. Fresh strawberry vines were ensiled in three groups: two experimental groups inoculated with strains Z and R (1.0&#x202f;&#xd7;&#x202f;10&#x202f;CFU/g fresh weight) and a control group (CK) treated with physiological saline. Samples were collected on days 1, 3, 5, 7, 15, 30, and 45 of fermentation for analysis. The LAB-treated silage was subsequently incorporated into Hu sheep diets to evaluate its effects on growth performance. RESULTS: The identification results indicated that strain Z wasand strain R was. Both treatment groups exhibited significantly higher crude protein (CP) content (&#x202f;<&#x202f;0.05) and markedly lower NH-N content (&#x202f;<&#x202f;0.05) compared to the CK group. Notably, supplementation withsignificantly reduced tannin content in strawberry vines (&#x202f;<&#x202f;0.05) compared to other two groups. By day 3, the pH values in the treatment groups were significantly lower than those in the CK group (&#x202f;<&#x202f;0.05), withtreatment group showing significantly lower pH thangroup throughout days 3 to 15 (&#x202f;<&#x202f;0.05), indicating more rapid silage stabilization. In terms of fermentation quality, lactic acid (LA) and acetic acid (AA) contents in the treatment groups were significantly higher than in the CK group (&#x202f;<&#x202f;0.05). Microbial community analysis demonstrated that both treatment groups effectively suppressed the growth of harmful microorganisms at both the phylum and genus levels, withgenus abundance reaching 54.18% ingroup compared to only 0.98% in CK by day 3. Furthermore, when used as roughage for Hu sheep, LAB-fermented strawberry vine silage significantly improved average daily gain (ADG) (&#x202f;<&#x202f;0.05) and enhanced the apparent digestibility of dry matter (DM), neutral detergent fiber (NDF), and CP (&#x202f;<&#x202f;0.05). Inclusion of strawberry vine silage fermented bymarkedly reduced the relative abundances of the predominant ruminal generaand. CONCLUSION: LAB supplementation significantly improved the silage quality of strawberry vines by effectively inhibiting putrefactive processes during the late fermentation stage of high-moisture silage. Moreover, the use of strawberry vine silage as feed markedly enhanced the growth performance in Hu sheep.