Forage Potential of Pearl Millet and Forage Sorghum Alternatives to Corn under the Water-Limiting Conditions of the Texas High Plains: A Review

Diminishing irrigation water from the Ogallala aquifer to produce forage crops is jeopardizing the beef and dairy industries in the Texas High Plains (THP). The principal feed ingredient of the beef and dairy sectors is corn (Zea mays L.) silage, which is produced near the feeding operations to minimize transport costs, unlike concentrated feed, which can be transported long distances. The declining pumping capacity of irrigation wells hinders the ability to sustain a supply of water for profitable corn production in the THP. Forage sorghum [Sorghum bicolor (L.) Moench] and pearl millet [Pennisetum glaucum (L.) R. Br.] are known for their ability to tolerate drought and heat, which enables them to produce high forage yields with less water than corn. Pearl millet and sorghum can also be harvested as hay, greenchop, or silage like corn. Introduction of the brown midrib (BMR) trait into pearl millet and sorghum has enhanced their nutrient composition. Brown midrib is a genetic trait associated with reduced lignin synthesis, resulting in enhanced digestion of forage fiber in the bovine (Bos taurus) rumen, thereby increasing weight gain and milk production per ton of forage fed over non-BMR types. Therefore, BMR forage sorghum and BMR pearl millet could be potential alternative forage crops where water is insufficient to grow corn silage in the THP. Hence, the objective of this review paper is to compare the water use efficiency, nutritional composition, associated antinutritional compounds, animal performance, and potential yields of BMR forage sorghum and BMR pearl millet with corn.