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ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #399139
Research Project: Strategies to Manage Feed Nutrients, Reduce Gas Emissions, and Promote Soil Health for Beef and Dairy Cattle Production Systems of the Southern Great Plains

Location: Livestock Nutrient Management Research

Title: Utilizing gas flux from an automated head chamber system to estimate dietary energy values in cattle fed a finishing diet

Author
item PROCTOR, JARRET - Texas A&M University
item SMITH, JASON - Texas A&M Agrilife
item Gunter, Stacey
item Beck, Matthew

Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2022
Publication Date: 5/4/2023
Citation: Proctor, J.A., Smith, J.K., Gunter, S.A., Beck, M.R. 2023. Utilizing gas flux from an automated head chamber system to estimate dietary energy values in cattle fed a finishing diet [abstract]. Journal of Animal Science. 101(Supplement 1):74-75. https://doi.org/10.1093/jas/skad068.087.
DOI: https://doi.org/10.1093/jas/skad068.087

Interpretive Summary:

Technical Abstract: Automated head chamber systems (AHCS; GreenFeed, C-Lock Inc., Rapid City, SD) provide estimates of daily flux of methane (CH4), carbon dioxide (CO2), and oxygen (O2) from free roaming cattle. This provides the opportunity to conduct energetic research from cattle in their production environment. One opportunity is the comparison of net energy for maintenance (NEm) and gain (NEg) values of performance-estimated [PE; peNEm and peNEg; Mcal×(kg DMI)-1, respectively] to gas-estimated (GE) NEm and NEg [geNEm and geNEg; Mcal×(kg DMI)-1, respectively] values derived from AHCS gas flux estimates. To assess this, yearling steers (n = 54; initial BW = 484.1 ± 26.0 kg) were assigned to one of two pens containing an AHCS feed bunks designed to measure individual feed intake (Calan Gate; American Calan, Northwood, NH) Steers were transitioned to one of three finishing diets and were then fed for 80 d. Paired day initial and final unshrunk BW were measured on d 0 and 1 and on d 79 and 80, respectively. Following the feeding period, steers were transported to a commercial abattoir where carcass data was collected. Average daily gas flux was utilized to calculate heat production (HP), ignoring the energy losses from urinary nitrogen. Empty body weight (EBW) and empty body gain (EBG) were calculated and used to estimate retained energy (RE). The estimates of RE and HP were used to calculate ME intake and DMI was used to quantify dietary ME content. Through previously established cubic models, geNEm and geNEg were calculated. Ultimately, geNEm and geNEg were estimated from gas flux, DMI, ADG, and initial and final BW. A previously established quadratic model was used to estimate peNEm and peNEg using calculated energy requirements and available carcass parameters. Statistical analyses to compare the PE and GE energy values were conducted utilizing R (v.4.1.0) to assess precision (Pearson Correlation; r), method agreement (Lin’s Concordance Coefficient Correlation; CCC), Root Mean Square Error of Prediction (RMSEP), and Relative Prediction Error (RPE; RMSEP as a % of average performance estimated values). On average, PE provided greater estimates of NEm (0.074 Mcal×(kg DMI)-1) and NEg (0.070 Mcal×(kg DMI)-1) relative to GE. The GE and PE provided values which were highly correlated and had excellent agreement (r = 0.92, P < 0.01; CCC = 0.87) for both NEm and NEg. Additionally, predictive capability was high for NEm (RMSEP = 0.12; RPE = 5.3%) and NEg (RMSEP = 0.11; RPE = 6.8%) between PE and GE values. The excellent agreement between PE and GE NEm and NEg values suggest that researchers can utilize AHCS to conduct energetic studies with cattle in their production environment. Moreover, the GE methodology provides an alternative method for retrospective assessment of animal energetic efficiency.