Differences in nutritional characteristics of three varieties of sorghum grain determine their in vitro rumen fermentation

Spanish Journal of Agricultural Research

Zahia Amanzougarene¹ 

[1] Universidad de Zaragoza-CITA, Instituto Agroalimentario de Aragón (IA2), Dept. Producción Animal y Ciencia de los Alimentos. Miguel Servet 177, 50013 Zaragoza

关键词: starch;    tannins;    protein;    polyethylene glycol;    gas production;   

DOI  :  10.5424/sjar/2018163-13010

学科分类：农业科学（综合）

来源: I N I A

【 摘 要 】

The effect of phenolic compounds and protein matrix on microbial fermentation of three sorghum grains (S1, S2 and S3) were studiedin vitro . Total phenolics and total tannins concentration (g/kg dry matter, DM) were 1.5 and 0.2 for S1, 19.3 and 8.1 for S2 and 2.6 and 1.3 for S3. Protein enzymatic digestibility was 0.614, 0.226 and 0.454, respectively. Trial 1 was conducted for 24 h, without or with polyethylene glycol (PEG) to determine the effect of phenolic compounds on fermentation. Without PEG, gas production for S1 was the highest after 24 h (257, 237 and 238 mL/g organic matter, for S1, S2 and S3;p< 0.05), and higher proportion of propionate at the expense of acetate was recorded with S3 after 6 h. Gas produced with S1 and S3 remained unaffected ( p> 0.10), but increased in S2 by 0.21 to 0.30 withvs.without PEG. No differences in gas production between S1 and S2 were observed with PEG, S3 recording the lowest ( p< 0.05) values from 8 h onwards. Addition of PEG reduced proportion of butyrate ( p< 0.05) and increased three-fold lactate (1.62vs.4.98 mM;p< 0.001). In Trial 2 (12 h) gas production followed a similar pattern. Without PEG, starch disappearance was the highest in S1 (0.356, 0.231 and 0.216, respectively), but no differences were recorded with PEG. Considering differences in protein digestibility and the effect of phenolic compounds, the effect of starch nature and structure on fermentation is apparently minor. Colour of grain is not necessarily related to   phenolic compounds proportion or rumen utilization.

【 授权许可】

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