Abstract

VILLARREAL-SILVA, Mariana et al. Physicochemical characteristics of nine sorghum (Sorghum bicolor L. Moench) hybrids and their relationship to starch content and ruminal digestion. Rev. mex. de cienc. pecuarias [online]. 2015, vol.6, n.3, pp.243-261. ISSN 2448-6698.

Nine grain sorghum hybrids (bicolor Sorghum L. Moench) were analyzed to evaluate the relationship between the physical [dry matter (DM), thousand grains weigh (TGW), particle size (PS), relative density (RD), area surface (AS) and particles for gram (PG), hard endosperm (HE) and soft endosperm (SE)]; and chemical characteristics [total nitrogen (N), acid detergent fiber (ADF), neutral detergent fiber (NDF), total starch (S), soluble starch (S-S), insoluble starch (I-s)]. The predicted ruminal starch digestion (PRSD) was determined enzymatically from the S-S and I-S fractions. The average of TGW, PS, RD, AS, PG and HE were 24.61 g, 3.17 mm, 1.30 g/cm³, 17.44 cm²/g, 30.33 and 46.68 % respectively. The average (%) of DM, CP, FDN, FDA, S, S-S and I-S were 92.47, 8.19, 19.17, 8.30 69.58, 6.00 and 47.74 respectively. The concentration of tannins was very low (<0.003 eqCat). The PRSD averaged 66.04 ± 1.24 % (range 64.61 to 68.42). No relationship was detected (P>0.05) among the physical or chemical variables with the total content of starch in the grain; however, the variables relative density and area surface, significantly increases prediction (PRSD,% = 74.058 - 0.108HE + 0.027AS - 5.887RD, R²= 0.77, P<0.05). According to the study, the sorghum hybrids are of intermediate hardness, free of tannins and with a potential of ruminal starch digestion of 66 %.

Keywords : Sorghum bicolor; Starch; Digestion; Physicochemical composition.