Effects of Plant Secondary Metabolites on Methane Production and Fermentation Parameters in In vitro Ruminal Cultures

• Main Authors: Mihaela Giuburunca, Adriana Criste, Daniel Cocan, Radu Constantinescu, Camelia Răducu, Vioara Mireșan
• Format: Article
• Language: English
• Published: Agroprint Timisoara 2014-10-01
• Series: Scientific Papers Animal Science and Biotechnologies
• Subjects: greenhouse gases, in vitro, methane, plant secondary metabolites, rumen, ruminal fermentation
• Online Access: http://spasb.ro/index.php/spasb/article/view/1729

Enteric fermentation process is of concern worldwide for its contribution to global warming. It is known that ruminant animals, due to natural fermentation process contribute substantially to the increase in methane production. Methanogenesis process represents besides its contribution to greenhouse gases emissions an energy loss to the animal. To reduce ruminal methane productions in an ecologically and sustainable way, many attempts have been initiated, such as: uses of chemicals additives or ionophore antibiotics, defaunation process or immunization against ruminal methanogenesis. In the last years, a new strategy has been evaluated whether plant secondary metabolites can be used as natural additives to reduce ruminal methane emissions. The present study has been conducted to investigate the effects of trans-cinnamic, caffeic, p-coumaric acids and catechin hydrate, four plant secondary metabolites (PSMs) on methane production and fermentation in in vitro ruminal cultures. The four PSMs were added anaerobically in a 6 mM concentration to 100 ml serum bottles containing 500 mg grass hay as a substrate, 10 ml rumen fluid collected from a fistulated sheep before morning feeding and 40 ml 141 DSM culture medium. The bottles were incubated at 39 ̊C. After 24 h, the following variables were measured: total gas volume, pH, methane and volatile fatty acids (VFAs) production. The results showed that caffeic (p = 0.058) and p-coumaric (p = 0.052) acids tended to decrease methane production in comparison to control but the decrease was not statistic significantly at α= 0.05. The other two PSMs had no significant effect on methane production. Addition of PSMs did not affected the total gas volume, the pH and VFAs profile (P>0.05) in relation to the control (no PSM added). In conclusion, caffeic and p-coumaric acids in 6 mM concentration showed some promising effects for decreasing ruminal methane emissions without affecting ruminal fermentation parameters but further experiments with other concentrations needs to be done.