Carbohydrate and protein composition and kinetic degradation of sorghum silage stored long-term

ABSTRACT: This study evaluated the effect of different storage periods on the carbohydrates and protein fractions and in vitro degradation kinetics of whole-plant sorghum silage. Sixteen experimental silos were used in a completely randomized design to evaluate four storage periods: 45, 90, 180, and 360 days with four replications each storage period. Each storage period effect was studied using polynomial regression, and equations were obtained using the solution option. A significance level (α) of 0.05 was considered. Storage periods quadratically affected silage dry matter, lactic acid, and acetic acid. The storage period linearly affected the silage concentration of propionic and butyric acids. Moreover, soluble carbohydrate fractions and insoluble ones decreased over the storage. Storage periods increased PA, PB2, and PB3 protein fractions and a 0.0884g/kg/day improvement of in vitro dry matter degradation. Long-term storage reduces sorghum silage quality through the lower soluble sugar and soluble fiber content and increased indigestible fiber and protein. We suggested that the nutritional composition changes in sorghum silage over the storage period must be considered for diet formulation.