Effect of Chinese herbal medicines on rumen fermentation, methanogenesis and microbial flora <i>in vitro</i>

Abstract

This study was carried out to evaluate the effects of three Chinese herbal medicines (CHMs) on rumen fermentation, methane emission and population of ruminal microbes using an in vitro gas production technique. Three healthy wethers of Dazu Black goats with similar bodyweights and permanent rumen fistulae were utilized as donors of ruminal fluid. The three botanical medicines were cablin patchouli herb (CPH), atractylodes rhizome (AR) and Amur cork tree (AC). Each CHM was added at a level of 25 g/kg to the substrate dry matter. In vitro gas production was recorded, and methane concentration was determined at 12 and 24 hours of incubation. After 24 hours, the incubation was stopped, and the inoculants were measured for pH, ammonia nitrogen and volatile fatty acids (VFAs) concentrations. Total deoxyribonucleic acid of ruminal microbes was extracted from the inocula, and populations were determined by a real-time quantitative polymerase chain reaction. Populations of total rumen methanogens, protozoa, total fungi, Ruminococcus albus, Fibrobacter succinogenes and Ruminococcus flavefaciens were expressed as a proportion of total rumen bacterial 16S ribosomal deoxyribonucleic acid. Compared to the control, CPH decreased gas production and methane production at 12 and 24 hours of incubation, and inhibited methanogens and total fungi growth. AR decreased acetate to propionate ratio, and methanogens and total fungi populations, but increased propionate molar proportion. AC decreased total VFA concentration, acetate to propionate ratio, gas production at 12 and 24 hours of incubation, methane production at 12 and 24 hours of incubation, and methanogens and total fungi growth, but increased the propionate molar proportion. In conclusion, CPH and AC both suppressed methanogenesis significantly, and the suppression was mediated primarily via the direct action against the rumen microbes involved in methane formation. AC also indirectly abates methane release by occupying the hydrogen (H 2) normally utilized for methanogenesis.

Gas Production, Digestibility and Efficacy of Stored or Fresh Plant Extracts to Reduce Methane Production on Different Substrates

“…Aloe vera (AV), Azadirachta indica (AZ), Moringa oleifera (MO), Tithonia diversifolia (TD), Jatropha curcas (JA) and Carica papaya (CP) have been reported to possess different phytochemicals such as anthraquinones, saponins, essential oils, catalase, azadirachtin, diastase and different digestive enzymes that could influence ruminal fermentation [1,2,12,13]. In a previous study [2], extracts of these plants, at 50 mg/kg substrate, reduced in vitro methane production and also increased the digestibility of Eragrostis hay, a low-quality roughage diet.…”

Haematology and Serum Biochemical Indices of Lambs Supplemented with Moringa oleifera, Jatropha curcas and Aloe vera Leaf Extract as Anti-Methanogenic Additives

“…The use of medicinal plants as dietary additives is gaining increasing research interest due to the wide biological diversity and potential beneficial effects for sustainable livestock production [1].…”

“…The plant secondary metabolites (PSMs) (also called phytonutrients) inherent in these medicinal plants have been found to exhibit strong antibacterial and antifungal properties, resulting in strong antimethanogenic properties in ruminant animals among other benefits reported in different studies [1,2]. Equally, some medicinal plants and their extracts tend to improve nutrient digestibility in ruminant livestock [3].…”

“…The use of medicinal plants as dietary additives is gaining increasing research interest due to the wide biological diversity and potential beneficial effects for sustainable livestock production [ 1 ]. The plant secondary metabolites (PSMs) (also called phytonutrients) inherent in these medicinal plants have been found to exhibit strong antibacterial and antifungal properties, resulting in strong antimethanogenic properties in ruminant animals among other benefits reported in different studies [ 1 , 2 ]. Equally, some medicinal plants and their extracts tend to improve nutrient digestibility in ruminant livestock [ 3 ].…”

The Use of Chinese Skullcap (Scutellaria baicalensis) and Its Extracts for Sustainable Animal Production

“…At present, the application of medicinal herbs and their extracts in animal production is still at the emerging stage. It has been proven that medicinal herbs can effectively improve the utilization of feed protein, and the performance of growth and reproduction in animals [ 10 , 11 ], modulate rumen fermentation towards high efficiency [ 12 , 13 , 14 ], increase feed intake and digestibility by affecting feed intake behaviors and the secretion of digestive enzymes [ 14 ], alleviate the effects of stress by enhancing antioxidant ability [ 15 , 16 ], and consequently improve the health status of animals. Furthermore, the antimicrobial effects of medicinal herbs can also be used for the prevention and treatment of diseases.…”