Effect of Syzygium aromaticum L. extract on ruminal fermentation and degradability in vitro

Abstract

To evaluate the effect of increasing doses (0, 0.6, 1.2 and 1.8 mL g(-1) DM) of Syzygium aromaticum extract on ruminal fermentation and degradability in vitro, using a diet for growing lambs as a substrate. The chemical composition of the diet and the compounds of the S. aromaticum extract were determined. The ruminal fluid of four Pelibuey lambs in the growth stage (21 +/- 0.3 kg live weight) was used to perform the in vitro rumen fermentation test (IVRF), total gas production (TGP) and in vitro rumen degradability (IVRD) test. The addition of increasing doses of S. aromaticum extract in the diet generated a positive quadratic effect (p < 0.05) in the lag phase before starting the TGP and the TGP rate, while in the TGP asymptote, accumulated TGP, dry matter degradability (DMD), short chain fatty acids (SCFA) and metabolizable energy (ME) the quadratic effect was negative. In a second degradability test where only the dose of 0.6 mL g(-1) DM was evaluated, the extract did not influence (p > 0.05) the DMS at 6, 18 and 48 h of fermentation, and although it decreased at 24 h (p < 0.05) 8.9\%, at 12 and 72 h it increased (p < 0.05) to 3.0 and 5.9\%, respectively. In conclusion, the S. aromaticum extract at a dose of 0.6 mL g(-1) DM favorably modifies the in vitro ruminal fermentation and degradability.