In increasing world population, with estimates of more than 9 billion people by 2050, and a decreasing cattle supply necessitates the use of feed technologies to meet the current and future demand of beef. Feed additives, such as ractopamine-HCl (Optaflexx, Elanco Animal Health, Greenfield, Ind.), promote growth efficiency and lean tissue weight gains. The ability to take advantage of increased animal efficiency and lean weight gains can give the beef industry the ability to maximize pounds of beef produced to meet demands.
Beef produced from heifers (young female cattle) makes up a considerable portion (approximately 28 to 29 percent) of the total beef supply (ERS, 2014). Due to hormonal changes, heifers tend to be more variable in their feedlot performance than steers, especially when fed ractopamine-HCl (Quinn et al., 2008).