Strategic use of tannins as means to limit methane emission from ruminant livestock
Introduction
There are some indications that tannins in the diet might help to reduce ruminal methane production either when included in significant proportions in temperate forage legumes [1] or when supplemented as purified tannin extracts [2]. Similarly, previous own in vitro experiments [3] presented indirect evidence that tannins, prevalent in the tropical shrub legume Calliandra calothyrsus, might be responsible for the methane production to be lower than with an unsupplemented low-quality grass diet and especially than with diets supplemented with Arachis pintoi or Cratylia argentea (tropical legumes low in tannins). However, it is still unclear (i) whether the tannin supplementation either through tanniniferous legumes or via tannin extracts is really effective in methane mitigation and (ii) to which extent this is associated with seriously adverse effects in terms of feeding value of the complete diet. These aspects were tested in two experiments, one of them with sheep using the respiratory chamber technique.
Section snippets
Materials and methods
In Experiment 1, the test diets consisted either of a tropical grass fed alone (Brachiaria humidicola) or of combinations of this grass with three different legume supplements. These made up 1/3 of dietary dry matter (DM) and were composed either of C. argentea alone, C. calothyrsus alone, or a 1:1 mixture of both legumes. The four diets were evaluated with the rumen simulation technique (Rusitec) [4]. Briefly, fermenters were filled with 890 mL strained rumen fluid obtained from a
Results and discussion
In Experiment 1, ammonia concentration in the fermenter fluid was increased (P < 0.05) by supplementation with C. argentea alone or in mixture with C. calothyrsus, but was not affected (P > 0.05) by supplementation with C. calothyrsus alone (see Table 1). Ammonia concentration decreased linearly (P < 0.001) and quadratically (P < 0.05) with increasing C. calothyrsus proportion in the legume supplement. Total volatile fatty acid (VFA) concentration increased (P < 0.05) with any type of supplementation
References (6)
Saponin rich tropical fruits affect fermentation and methanogenesis in faunated and defaunated rumen fluid
Anim. Feed Sci. Technol.
(2003)- et al.
The tannin theory of methanogenic toxicity
Biol. Wastes
(1989) - et al.
Methanogenesis from forages fed to sheep
Proc. N. Z. Grassl. Assoc.
(2002)
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2017, Climate Risk ManagementCitation Excerpt :Supplements such as tannins are also known to have the potential to reduce emissions. Tannins are able to displace the nitrogen excretion from urine to feces to produce an overall reduction in emissions (Dickie et al., 2014; Hess et al., 2006). Fertilizer application on animal feed crops increases nitrous oxide emissions (Bouwman, 1996).