Effects of Feeding a Commercial Starch Binding Agent during Heat Stress on Enteric Methane Emission, Rumen Volatile Fatty Acid Contents, and Diet Digestibility of Merino Lambs

• Published in: Atmosphere Vol. 14; no. 3; p. 605
• Main Authors: Prathap, Pragna, Chauhan, Surinder S, Leury, Brian J, Cottrell, Jeremy J, Joy, Aleena, Zhang, Minghao, Dunshea, Frank R
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-03-2023
• Subjects: Animals; Binders (materials); Binding; Climate change; Diet; Digestibility; Distribution; Emissions; Environmental aspects; Fatty acids; feed additives; Feeds; Fermentation; Food and nutrition; Gases; Global warming; greenhouse gas; Heat; Heat stress; Heat tolerance; Humidity; Laboratories; Lambs; maize; Metabolism; Methane; Methane emissions; Rumen; Rumination; sheep; Starch; temperature; Temperature effects; Thermal cycling; Wheat; United Kingdom; United Kingdom > UK; Australia; United States > US
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos14030605

Twenty-four Merino lambs were allocated to three dietary treatment groups to determine the effects of a dietary starch and protein binding agent and heat stress on methane (CH4) emissions and rumen parameters. The diets were a wheat-based diet (WD), a 2% Bioprotect™ (Bioprotect™, RealisticAgri, Rutland, UK) treated wheat-based diet (BD), and a maize-based diet (MD) for 3 periods of 1-week duration. During Period 1 (P1) the lambs were maintained under thermoneutral conditions and at a 1.7 × Maintenance (M) level. During P2 and P3, the lambs were maintained under cyclic heat stress conditions and fed at 1.7 × M and 2.0 × M, respectively. Total CH4 production was lower for the BD diet than the WD diet, which in turn was lower than the MD diet (p < 0.001). Total CH4 production was lower during P2 than P1 with P3 intermediate (p = 0.04). Rumen total volatile fatty acid (TVFA) concentrations were higher for the WD diet than the MD diet with the BD diet intermediate (p = 0.01). Rumen TVFA concentrations were lower during heat stress than under thermoneutral conditions (p < 0.001). Whole tract starch digestibility was higher for the BD and WD diets than the MD diet (p < 0.001). In conclusion, feeding Merino lambs the BD diet reduces CH4 emissions without reducing starch digestibility.