Improving efficiency in beef production systems using composite parasitism diagnostics and rumen microbial modulation in beef cattle

Abstract

Improving efficiency in beef production systems requires integrating sound animal health management with optimal rumen function. A variety of diagnostic and management approaches have been developed to identify opportunities for targeted interventions that improve both animal health and rumen performance. Using these approaches, a series of experiments evaluated diagnostics and nutritional strategies influencing cattle health, rumen microbial activity, and greenhouse gas emissions in beef production systems. In experiment 1, a mob composite fecal sampling protocol was evaluated as an alternative to traditional individual fecal egg count diagnostics for estimating parasite loads in commercial feedlot cattle. Fecal samples (n = 1,060) were collected from cattle in commercial feedlots (n = 12) and sale barns (n = 1), with pen sizes ranging from 64 to 225 head. Individual fecal egg count values were determined using 20 individual samples per pen (IDV). Mob composite samples were created by combining fecal material from 10 fresh fecal pats to create two composite samples representing 20 fecal pats within each pen (MOB). Lin’s concordance correlation coefficient compared mean fecal egg counts between sampling methods. Mob composite and individual sampling methods demonstrated a 91.7% agreement in mean fecal egg counts (95% CI: 86.4-95.0%). Results indicate that the two 10-sample mob composite protocol provides an effective and cost-efficient method for evaluating parasite loads in commercial feedlot cattle. Experiment 2 evaluated rumen microbial populations, greenhouse gas emissions, and growth performance of commercial beef steers fed a high forage diet supplemented with or without a commercial essential oil blend, Agolin©(Agolin Ruminant, Alltech, Nicholasville, KY). Steers (n = 36; initial BW = 317 ± 34 kg) were assigned to either a control diet (CON) or a diet supplemented with Agolin (AGO) during a 70-d trial. Methane and carbon dioxide emission were measured using Greenfeed Automated Head Chamber Systems (AHCS; C-Lock Inc., Rapid City, SD). Steers supplemented with Agolin produced 4% less methane (240 g/d) compared with CON steers (250 g/d; P = 0.03). Carbon dioxide emissions did not differ between treatments (P = 0.15). Average daily gain and dry matter intake did not differ between treatments (P  0.42). Shifts in rumen protozoal populations away from Holotrich populations towards Entodiniomorph populations indicated altered rumen fermentation dynamics for steers supplemented with Agolin. Results from these experiments demonstrate that efficiency of beef cattle systems can be influenced by improvements to practical diagnostic approaches. Additionally, dietary interventions, such as Agolin supplementation, can alter rumen fermentation dynamics to further enhance production efficiency. Improved parasite diagnostics and targeted rumen microbial modulation support each enhance beef cattle production efficiency. These results emphasize the importance of continued research to expand diagnostic tools and product solutions that support sustained improvements in beef production efficiency.