Genetic improvement and quality parameters of sorghum silage (Sorghum bicolorL. Moench) in relation to maize silage (Zea maysL.)

Abstract

The aim of this review was to report studies on genetic improvement of sorghum (Sorghum bicolor L. Moench), intended for obtaining genotypes with better forage characteristics for silage production. Among the forages destined to silage production, the sorghum constitutes a good alternative, with production superior to 20 t ha-1 of dry biomass. The main advantage of using sorghum is the possibility of producing higher biomass volume and better quality silage, with digestible fibers of great animal consumption and performance, in areas where cultivation restrictions for maize and others forages are risky and/or impossible. One of the limitations of using sorghum on animal nutrition is the tannin concentration in the grain, relating negatively with dry mass digestibility. By means of genetic improvement, such situation, through the knowledge of genetic inheritance of this characteristic, enabled 95% of the national sorghum to be devoid from tannin in the grains. As for the bromatological composition of silage, the sorghum presents fiber levels on neutral detergent varying from 52% to 56% against 45% to 64% in maize, in acid detergent from 32% to 35% against 28% to 35% in maize, and dry matter digestibility in vitro from 52% to 56% against 54% to 78% in maize, evidencing strong similarities regarding these parameters. The genetic improvement has made the sorghum cultivation an alternative to the maize replacement for animal nutrition.