Methane emission by goats consuming diets with different levels of condensed tannins from lespedeza

• Published in: Animal feed science and technology Vol. 144; no. 3; pp. 212 - 227
• Main Authors: Animut, G., Puchala, R., Goetsch, A.L., Patra, A.K., Sahlu, T., Varel, V.H., Wells, J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-07-2008; [New York, NY]: Elsevier Science; Elsevier
• Subjects: animal feeding; Animal productions; Biological and medical sciences; Boer; Condensed tannins; diet; digestibility; experimental diets; Feed and pet food industries; Food industries; forage composition; Fundamental and applied biological sciences. Psychology; gas emissions; gas exchange; Goats; Lespedeza; Lespedeza striata; males; Methane; proanthocyanidins; rumen fluids; rumen microorganisms; Sorghum bicolor; Spanish (goat breed); Terrestrial animal productions; Vertebrates; EE; IVTDMD; Methane; DE; aNDF; ADF; Goats; G; DM; K; CP; VFA; CT; PEG; RE; BW; ME; GE; OM; Condensed tannins; Dairy animal; Flavonoid; Vertebrata; Polyphenol; Mammalia; Tannin; Diet; Goat; Artiodactyla; Ungulata
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/j.anifeedsci.2007.10.014

Twenty-four yearling Boer
×
Spanish wethers (7/8 Boer; initial body weight (BW) of 34.1
±
1.02
kg) were used to determine effects on methane (CH
4) emission of dietary levels of a condensed tannin (CT)-containing forage, Kobe lespedeza (
Lespedeza striata; K), and a forage very low in CT, sorghum-sudangrass (
Sorghum bicolor; G). Treatments were dietary K levels (dry matter (DM) basis) of 1.00, 0.67, 0.33, and 0 (100, 67, 33, and 0
K, respectively). Forages were harvested daily and fed at approximately 1.3 times maintenance metabolizable energy requirement. The experiment lasted 21 days, with most measures on the last 8 days. The CT concentration was 0.3 and 151
g/kg
DM in G and K, respectively. DM intake was similar among treatments (
i.e., 682, 675, 654, and 648
g/day; S.E.
=
30.0) and gross energy (GE) digestibility increased linearly (P<0.05) with decreasing K (0.472, 0.522, 0.606, and 0.666 for 100, 67, 33, and 0
K, respectively). CH
4 emission changed quadratically (P<0.05) with decreasing K (10.9, 13.8, 17.6, and 26.2
l/day; 32, 42, 57, and 88
kJ/MJ GE; 69, 81, 94, and 133
kJ/MJ digestible energy for 100, 67, 33, and 0
K, respectively).
In vitro CH
4 emission by incubation of ruminal fluid for 3 weeks with a medium for methanogenic bacteria and other conditions promoting activity by methanogens also was affected quadratically (P<0.05) by K level (7.0, 8.1, 9.2, and 16.1
ml for 100, 67, 33, and 0
K, respectively). The total bacterial count of ruminal samples was similar among K levels, but the number of total protozoa increased linearly (P<0.05) as K declined (8.3, 11.8, 15.6, and 27.1
×
10
5
ml
−1 for 100, 67, 33, and 0
K, respectively). The CT-containing forage K decreased CH
4 emission by goats regardless of its feeding level, although the effect per unit of K increased with decreasing K. Forage type (
i.e., legume
versus grass) may have contributed to the effect of K on CH
4 emission, but most of the change appeared attributable to CT, which appeared to directly impact activity of methanogenic bacteria, although alterations of protozoal activity could have been involved. These findings suggest that relatively low dietary levels of CT could be employed to lessen CH
4 emission without a marked detrimental effect on other conditions such as total tract protein digestion.