Effects of a Proprietary Kelp Blend Product on Enteric Methane Production and Tissue Residues in Cattle

Abstract

Three experiments were performed investigating bovine enteric methane (CH4) production inhibition using a proprietary kelp blend product (PKBP) containing a halogenated methane analog (i.e., bromoform). Calves were fed a corn-silage basal diet top-dressed with the assigned treatment, with rations provided at 1.5 × NEm in Experiments 1 and 2 (n = 12 and 6 steers, respectively) and ad libitum in Experiment 3 (n = 9 steers). In Experiment 1, we evaluated bromoform’s potency in decreasing CH4. Dry matter intake (DMI) was not affected by treatment (p ≥ 0.11; 0 vs. 52.5 ± 10.5 ppm bromoform), whereas bromoform supplementation decreased CH4 (p 4 recovery following bromoform removal from the ration. Bromoform treatments were fed on d1, but not the subsequent 8 d, to investigate residual effects. On d1, CH4 was below limits of detection for 20 ppm bromoform inclusion. Across days, a cubic response (p p = 0.53), average daily gain (p = 0.55), and gain:feed (p = 0.82) were not influenced by bromoform inclusion. Bromoform residues were undetectable in liver, kidney, adipose, and muscle samples collected at harvest. These experiments demonstrated that cattle fed PKBP experience short-term reductions in CH4 without tissue accumulation of bromoform and without evidence of effects on animal growth or feed consumption.

Keywords

• cattle
• methane mitigation
• bromoform
• residues
• growth performance