Effect of Mootral and Forage Amount on Methane Emission, Growth and Carcass Characteristics of Feedlot Steers

Description

Methane (CH₄)
production from enteric fermentation in ruminant animals is a contributor to
global greenhouse gas emissions. Because
CH₄ has an impact on increasing global temperatures, there is a push
for government regulations to reduce CH₄ from livestock animals. At
1.9% of U.S. CH₄ emissions
beef cattle are a large contributor to agricultural CH₄ emissions or
(EPA, 2020). Enteric CH₄ emissions are also a loss of energy for the
animal, accounting for 2-12% of energy loss from the ruminant animal (Johnson
& Johnson, 1995). This energy loss from the diet is contingent upon forage
content, where increasing forages in the diet increases CH₄ yield
(g/kg of gross energy intake; van Gastelen et al., 2019). Mootral is a feed
supplement that contains garlic (<i>Allium sativum</i>) and bitter orange (<i>Citrus
aurantium</i>) extracts. The organosulfur compounds in garlic the flavonoids
found in bitter orange extracts are known to decrease CH₄
production, (Busquet
et al., 2005a; Balcells et al., 2012; Seradj et al., 2014). However, it is unclear
how the forage content and Mootral inclusion will interact to effect CH₄production
and animal performance. Because feedlot cattle are fed
a range of forage:concentrate ratios while in the feedlot, it is important to
know how effective mitigation strategies are in different forage:concentrate
diets. Therefore, the objective
of the current study was to quantify CH₄ production and determine
growth, intake, and carcass characteristics of feedlot steers fed Mootral in
diets with a low, medium, and high forage content. Knowing the effect of garlic and flavonoids on
methanogenesis, we hypothesized that Mootral would decrease CH₄
emissions without impacting growth, intake, and carcass characteristics of
feedlot steers. We expect that the CH₄ mitigating ability of Mootral
will be greatest in the diet with the most forage. For the experiment, 144 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 42-46 and day 203-207. Data were analyzed using the GLIMMIX
procedure of SAS. There was an interaction (<i>P </i>= 0.03) between forage
content 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 (<i>P </i>≥ 0.22) of forage content or
Mootral on BW or average daily gain at any time, or on DMI from d 84 to slaughter
and overall. Intake from d 0-84 was lower and gain:feed from d 0-84 and overall
was greater (<i>P </i>= 0.04) for steers fed 68% compared to 15 or 41.5% corn
silage. On d 42-46, steers fed 41.5 and 68% corn silage had increased (<i>P </i>≤
0.02) methane emissions compared to steers fed 15% corn silage. Mootral did not affect
methane emissions on day 42-46 (<i>P</i> ≥ 0.47), but there was a forage effect, where steers fed
the 41.5 and 68% corn silage diets emitted more methane on a g/d (<i>P</i> = 0.05) and a g/kg of DMI (<i>P</i> = 0.007) basis and
tended (<i>P</i> = 0.07) to produce more
methane on g/kg BW basis compared to steers fed the 15% corn silage diet. Steers fed Mootral emitted less (<i>P </i>≤ 0.03)
methane on a g/d, g/kg DMI, and g/kg BW basis on d 203-207 compared to steers
not fed Mootral. Mootral tended to decrease (<i>P </i>≤ 0.09) fat thickness and
yield grade. In conclusion, increasing forage content increased methane
emissions and Mootral decreased methane production in 15% corn silage diets and
improved carcass leanness.

Links & Downloads

1. 10.25394/pgs.16766695.v1

Tags

Animal Nutrition

Methane

Beef Cattle

Additional Fields

Identifer	oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/16766695
Date	22 November 2021
Creators	Bryce Bitsie (11534065)
Source Sets	Purdue University
Detected Language	English
Type	Text, Thesis
Rights	CC BY 4.0
Relation	https://figshare.com/articles/thesis/Effect_of_Mootral_and_Forage_Amount_on_Methane_Emission_Growth_and_Carcass_Characteristics_of_Feedlot_Steers/16766695