Brown midrib resistence (BMR) corn

Abstract

T

his literature review was done to envestigate the research development on brown midrib resistance (BMR) variety corn that is known to have lower content of lignin in the forage yielded than those other varieties of corn. The low lignin content is associated with changes in concentration of phenolic acids and alteration of enzymes involved in lignin biosynthesis. The BMR corn have specific sign of reddish-brown coloration found in the center midrib on the underside of the leaf. The pigmentation appears in the stem with its lignifications visually associated with rind and vascular bundles. The coloration fades during maturing and may disappear on the leaves, but remains in the stalks. There were four BMR mutants were recorded naturally, namely: bm1, bm2, bm3, and bm4 , and the lesser lignin content were observed in bm3. Harvesting of corn plant generally at about 60 to 70 days after planting (milking stage of kernel), where more energy will be provided. The dry matter (DM) production approximately 2.5 t/ha lower or about 10 to 15% lesser than the conventional one. And after harvested the corn forages generally preserve as silage and given to the animals mostly for dairy cows in the stall. The BMR corn silage (BMRCS) fed to dairy cows usually resulted in increase of body weight and milk yield, reduce rumen pH, increase microbial synthesis therefore increases N content in milk, but no effect on fat content when it is compare to conventional corn. The lower rumen pH of cows fed BMRCS can be attributed to the lower pH of corn silage.