Young Scholar Presentation: Technology in Livestock Production: Use of Production Technologies to Improve the Sustainability of Meat Production

Improving the sustainability of livestock production has come under increasing producer, consumer, and regulatory scrutiny. Sustainability of livestock production is difficult to define with environmental, economic, and societal aspects. Although life cycle assessments and environmental emission testing are direct measures of environmental sustainability, production efficiencies such as feed efficiency and lean meat yield are also important measures of the sustainability of meat production. The public has also become increasingly wary of technology use in livestock and meat production. Therefore, it is important to assess and report the sustainability impacts of current and emergent technologies. Multiple projects in our laboratory have focused on this area of research.

Immunological castration (Improvest; Zoetis, Kalamazoo, MI) provides an alternative to physical castration (PC) for the reduction of boar odor while improving feed efficiency and ADG. Less is known however about the effects of Improvest on lean meat yield and value given the wide range of production factors in the finisher known to affect carcass attributes. The objectives of this study were to determine average effects of immunological castration (IC) on primal yield through a meta-analysis of the literature. Carcasses of IC barrows demonstrated a 1.24 unit improvement (P < 0.001) in carcass cutting yield compared with carcasses from PC barrows. From a sustainability perspective, increased carcass cutting yield results in more edible meat produced from an animal suggesting overall improvements in sustainability of pork production with this technology.

Metabolic modifiers such as ractopamine hydrochloride (RAC) have historically been used to increase feed efficiency and lean meat yield of cattle, pigs, and turkeys. While increasing efficiency and lean meat yield will improve sustainability, the direct effects of RAC usage in cattle on environmental emissions have been less well established. Therefore, our objective was to evaluate the effects of ractopamine hydrochloride on N excretion of finishing steers. Two blocks of 6 Angus × Simmental steers (N = 12) were fed a control or RAC diet and housed in metabolism stalls for total collection of feed, orts, feces and urine. Nitrogen balance analyses demonstrated feeding RAC resulted in a 13% reduction (P = 0.02) in total N excretion over the 35 d feeding period. Reductions in N excretion were observed with numerical improvements in LM area suggesting greater N incorporation in the form of increased protein accretion. Therefore, RAC usage in cattle can directly result in reduced environmental nitrogen emissions.