Effects of 3-nitrooxypropanol on feeding behavior and rumen fermentation in beef cattle fed a growing diet

First Place at Spring 3-Minute Thesis CompetitionSecond Place at the Denman Undergraduate Research ForumThird Place at the CFAES Undergraduate Research ForumMitigating enteric methane production from ruminants is critical for sustainable livestock operations. Three-nitrooxypropanol (NOP) is an effective feed additive for mitigating enteric methane production in beef cattle. However, feeding NOP to beef cattle often decreases feed intake and alters feed fermentation in the rumen. Therefore, the objective of the study was to determine whether changes in feed intake and rumen fermentation are caused by changes in feeding behavior when supplementing a growing diet with NOP. The experiment used 9 ruminally-cannulated beef steers in a repeated 3 × 3 Latin square design. Steers received one of the three following treatments: a control diet (CON); the CON diet supplemented with NOP (dNOP; 1g NOP per cow d-1); or the CON diet with an infusion of NOP into the rumen (NOPinf; 1g NOP per cow d-1). The CON diet was a typical high forage diet that is fed to growing beef cattle in the US. Rumen content was collected via cannula to examine rumen fermentation. Methane production of individual animals was measured using the Greenfeed system. To observe animal behaviors, cameras were installed to continuously record individual steers for 48 hours. Total duration and frequency of feeding, drinking, activity, and oral manipulation behaviors were collected. Meal time (min/d) and frequency of individual animals were calculated from feeding behavior. Rumen samples were collected via rumen cannula to determine rumen fermentation characteristics (i.e., pH, volatile fatty acid concentration, as well as lactate concentration. Data were analyzed using an analysis of variance model using the repeated measures Mixed Procedure of SAS (SAS Inst. Inc., Cary, NC). Feeding NOP decreased enteric methane production by approximately 18% compared with CON. Rumen fermentation was altered by NOP as expected (i.e., rumen pH and proportion of short chain fatty acids). However, there were no significant differences in feeding, drinking, or activity behaviors between treatments since total duration and frequency of oral manipulation behaviors (chain chewing, biting, and licking) were lower (P < 0.03) for dNOP and NOPinf compared to CON. According to the results, NOP changed rumen fermentation, but the changes were not caused by a change in feeding behaviors in beef cattle fed a growing diet.Animal Science Undergraduate Research Experience (ASURE) ProgramDSM Nutritional ProductsNo embargoAcademic Major: Animal Science