Enteric methane emissions, growth, and carcass characteristics of feedlot steers fed a garlic- and citrus-based feed additive in diets with three different forage concentrations

Abstract

One hundred and forty-four Angus x Simmental steers were allotted by body weight (BW; 363 kg), breed composition, and farm origin to a 3 x 2 factorial arrangement of 6 treatments (4 pens per treatment) to determine the effect of Mootral (garlic + citrus extract; 0.25% of the diet DM vs. 0.0%) on methane emissions, growth and carcass characteristics of feedlot cattle. During the first 84 days, cattle were fed three different forage concentrations in the diet (15, 41.5, or 68% corn silage) with or without Mootral. From day 85 to slaughter, corn silage was included at 15% of the diet DM with or without Mootral. Methane emissions were measured on day 42 to 46 and day 203 to 207. Data were analyzed using the GLIMMIX procedure of SAS. Mootral did not affect methane emissions on days 42 to 46 (P ≥ 0.47), but there was a forage effect, where steers fed the 68% corn silage emitted more methane on a g/d (P = 0.05) and a g/kg of DMI (P = 0.007) basis and tended (P = 0.07) to produce more methane on g/kg BW basis compared to steers fed the 15% corn silage diet. On d 203 to 207, steers fed Mootral emitted less (P ≤ 0.03) methane on a g/d, g/kg DMI, and g/kg BW basis compared to steers not fed Mootral. There was an interaction (P = 0.03) between forage concentration and Mootral for DMI from d 0 to 84, where Mootral decreased DMI of steers fed 15% corn silage but did not affect DMI of steers fed 41.5 or 68% corn silage. There were no effects (P ≥ 0.22) of forage concentration or Mootral on BW or average daily gain at any time, or on DMI from d 84 to slaughter and overall. However, overall calculated NEm and NEg tended to be greater for steers fed Mootral (P ≤ 0.10). Intake from d 0-84 was lower and gain:feed from d 0-84 and overall was greater (P = 0.04) for steers fed 68% compared to steers fed 41.5% corn silage. Calculated NEm and NEg from day 0 to 84 and overall were greater for steers fed 68% corn silage compared to steers fed 41.5% corn silage (P ≤ 0.03). Mootral tended to decrease (P ≤ 0.09) fat thickness and yield grade. In conclusion, increasing forage concentration increased methane emissions and Mootral decreased methane production in 15% corn silage diets and tended to improve carcass leanness.

Effect of a Garlic and Citrus Extract Supplement on the Lactation Performance and Carbon Footprint of Dairy Cows under Grazing Conditions in Chile

“…This emphasises the need to focus on enteric CH 4 mitigation strategies to achieve significant emission reductions and more sustainable dairy farming [ 55 ]. It is noteworthy that the current simulation did not include the potential enteric CH 4 -mitigating effect of GCE [ 11 , 12 , 13 , 14 ], which could further reduce the GHG emission intensity of milk. Indeed, it would be interesting for future LCA studies to evaluate how the combined effect of GCE in improving milk production and enteric CH 4 mitigation could influence the GHG emission intensity of dairy production.…”

“…Several studies have demonstrated the enteric methane mitigation effect of feeding a garlic and citrus extract (GCE) supplement to dairy cows, sheep and beef cattle [ 11 , 12 , 13 , 14 ]. Supplementing GCE in a total mixed ration (TMR) has been shown to increase the milk yield and feed efficiency of dairy cows [ 11 ], potentially through positive modulation of rumen fermentation, which increases the production of volatile fatty acids (VFA) [ 15 ].…”

Enteric methane emission reduction potential of natural feed supplements in ewe diets

“…Feeding GAR to feedlot steers (15 g/steer/d) only showed a reduction in CH 4 after 9 wk of supplementation ( Roque et al., 2019 ). Another study on feedlot steers (0.25% of DMI) had no effect on CH 4 over an 84 d period at differing inclusion levels of forage (15%, 41.5%, and 68%); however, during the finishing period (15% forage inclusion), a 26% reduction in CH 4 g/d was observed ( Bitsie et al., 2022 ). It is therefore difficult to pinpoint the reasoning for the inconsistent effects of GAR on CH 4 production in ruminants, as the aforementioned studies were conducted over a variety of time periods (21 to 207 d) and as part of differing feeding regimes (15% and 68% forage).…”

Preliminary Investigation of the Effects of Rosemary Extract Supplementation on Milk Production and Rumen Fermentation in High-Producing Dairy Cows

“…Plant extracts are potential rumen modifiers because of their antimicrobial activity against microorganisms [ 49 ]. The wide application of plant extracts for reducing ruminal methane emissions supports their role as rumen modifiers [ 50 ]. Therefore, it is essential to evaluate the effects of RE on rumen functions.…”