Effects of mixed modes on fermentation quality and In vitro gas dynamics of sorghum-sudangrass hybrid (Sorghum bicolor × S. sudanense) silage

Huan Liang, Jinghua Zhang, Guibo Liu, Yuan Li, Yongliang You, Haiming Zhao, Yemei Yang, Yan Fan, Jian Zhang, Bing Zeng

Abstract


Sorghum-sudangrass hybrid silage has poor fermentation characteristics owing to a high moisture content. Accordingly, a 3 × 4+1 factorial design was applied to investigate the effects of adding different types and amounts of hay (corn stalk, wheat straw, and alfalfa hay at 12.5 kg t-1, 25 kg t-1, 37.5 kg t-1, and 50 kg t-1) on the nutritive value, fermentation quality, 72 h dry matter digestibility, and gas dynamics in vitro to simulate the rumen fermentation of sorghum-sudangrass hybrid silage. Separated silage of sorghum-sudangrass hybrids had a high butyric acid content and a FLIEG’s scores evaluation ranking of only “Fair.” The addition of hay significantly improved the fermentation quality of mixed silage. With respect to hay type, adding wheat straw had the best fermentation quality, alfalfa hay had the best nutritive value, in vitro dry matter digestibility (IVDMD) (662.41 g kg-1), constant fractional rate (C) (0.28 mL h-1), and the average gas production rate (AGPR) (32.70 mL h-1) content. There were no differences in the cumulative gas production at 72 h (GP72h), asymptotic gas production generated at a constant fractional rate (A), and lag time before gas production commenced (lag) among the three hay types. With respect to quantity, 25 kg t-1 hay had the best fermentation quality, 50 kg t-1 hay had the best nutritive value and highest IVDMD content (662.81 g kg-1), 37.5 kg t-1 hay had the highest C (0.28 mL h-1) and AGPR (31.48 mL h-1) contents, 25 kg t-1 hay had the highest Half time (2.20 h), and there were no significant differences in GP72h, A, and lag among the four amounts. Considering both nutritive value and fermentation quality, the best mixed silage mode was 37.5 kg t-1 wheat straw.

Keywords


Additive; By-product; In vitro rumen fermentation; Silage quality.

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DOI: http://dx.doi.org/10.5433/1679-0359.2018v39n6p2807

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional