NUTRIENT USE EFFICIENCY EVALUATION OF BEEF CATTLE FEEDLOT

• DOI: 10.37572/EdArt_3007241926

• Palavras-chave: Feedlot nitrogen efficiency, Feedlot phosphorus efficiency, Mass balance feedlot.

• Keywords: Feedlot nitrogen efficiency, Feedlot phosphorus efficiency, Mass balance feedlot.

• Abstract:

  Feedlot´s high-intensity operations achieve average daily gains of 1.36-1.9 kg, with peak values up to 2.5 kg. Despite the efficient dietary practices that maximize digestibility and energy, feedlot systems are highly dependent on imported feed, making them susceptible to market fluctuations and posing environmental challenges due to nutrient waste. This study evaluates the Nutrient Use Efficiency (NUE) of Dry Matter (DM), Nitrogen (N), and Phosphorus (P) in a central Mexican feedlot with a maximum capacity of 8,000 animals, aimed at quantifying nutrient retention as live weight gain (LWG). A mass balance methodology was used to assess nutrient inputs and outputs over one year. The results indicated that the NUE was 15% for DM, 17% for N, and 29% for P, with the majority of nutrients lost in feed waste, manure and energy for maintenance. The findings suggest that while improvements in feed management, infrastructure, and genetic and sanitary measures can slightly enhance NUE, substantial gains are limited to about 5%. The most significant opportunity for improving overall NUE and reducing environmental impact lies in revaluing manure as a co-product rather than waste. Effective manure management can retain more nutrients within the system, thereby enhancing the efficiency and sustainability of feedlot operations. This comprehensive assessment underscores the importance of targeted strategies to optimize nutrient use in feedlots, highlighting the potential benefits of treating manure as a valuable resource. Feedlot nitrogen efficiency, Feedlot phosphorus efficiency, Mass balance feedlot.