Effect of plant secondary compounds on in vitro methane, ammonia production and ruminal protozoa population

Abstract

Aims: The objective of this study was to evaluate the potential of secondary plant metabolites from 38 sources to serve as antimethanogenic additives in ruminant diets. The effect of leaf tannins from these different plant sources on rumen fermentation, protozoal populations and methanogenesis was also studied. Methods and Results: Samples (200 mg dry matter, DM) were incubated without and with polyethylene glycol (PEG)-6000 (400 mg DM) as a tannin binder during 24-h incubation in the in vitro Hohenheim gas system. In the leaf samples, total phenol (g kg À1 DM) was maximum in Pimenta officinalis (312) followed by Oenothera lamarckiana (185) and Lawsonia inermis (105). Of the 38 samples, condensed tannins exceeded 4Á0 g kg À1 in only Alpinia galanga (7Á50), Cinnamomum verum (4Á58), Pelargonium graveolens (18Á7) and Pimenta officinalis (23Á2) and were not detected in seven samples. When the bioactivity of the leaf samples was assessed using the tannin bioassay, the percentage increase in the amount of gas produced during incubation of samples with the tannin-binding agent PEG-6000 over the amount produced during incubation without the tannin binder ranged from nil (zero) to 367%, with the highest being recorded with A. galanga leaves. The ratio of methane reduction per ml of total gas reduction was maximum with Rauvolfia serpentina (131Á8) leaves, followed by Indigofera tinctoria (16Á8) and Withania somnifera (10Á2) leaves. Total and differential protozoal counts increased with added PEG in twentytwo samples, maximum being in Pimenta officinalis. Increased accumulation of total volatile fatty acids during incubation with added PEG-6000 was recorded, and the values ranged from zero to 61%. However, the increase was significant in only 11 of the 38 tannin sources tested indicating noninterference of tannin on in vitro fermentation of carbohydrates by the majority of samples tested. Conversely, in 26 of 38 plant sources, the leaf tannins reduced N-digestibility as evidenced by increased accumulation of NH 3 -N with added PEG.Conclusions: Our study unequivocally demonstrated that plants containing secondary metabolites such as Rauvolfia serpentine, Indigofera tinctoria and Withania somnifera have great potential to suppress methanogenesis with minimal adverse effect of feedstuff fermentation. Significance and Impact of the Study: It was established that methanogenesis was not essentially related to the density of protozoa population in vitro. The tannins contained in these plants could be of interest in the development of new additives in ruminant nutrition.

Ruminal methanogenesis and biohydrogenation reduction potential of papaya (Carica papaya) leaf: anin vitrostudy

“…In a study by Tan et al (2011), 33% reduction in in vitro CH 4 production at the inclusion of 10 mg of purified CT from Leucaena/500 mg DM had been observed. In a study by Bhatta et al (2013), it was shown that plant leaves containing secondary metabolites as their contents such as Rauvolfia serpentine, Indigofera tinctoria and Withania somnifera have great potential to suppress methanogenesis with minimal adverse effect on feedstuff fermentation. Zmora et al (2012) indicated that Mentha piperita (MP) leaves which contain different classes of secondary metabolites at a concentration of 16.34 and 23.35 mg of MP to the 233.30 mg of substrate decreased rumen methane production at 24 h of incubation by altering the rumen micro-organisms' profiles without changing the profile of VFA and DM digestibility.…”

Papaya (Carica papaya) leaf methanolic extract modulates in vitro rumen methanogenesis and rumen biohydrogenation

“…CH 4 accounts for 2‐12% loss of dietary gross energy in ruminants and is a potent greenhouse gas with a global warming potential 23 times higher than that of carbon dioxide (CO 2 ) in trapping the heat (Bhatta et al . ; Intergovernmental Panel on Climate Change (IPCC) ). Therefore, reducing ruminal CH 4 not only improves the efficiency of nutrient utilization but also helps to protect the environment from global warming.…”

IN VITRO EVALUATION OF CONCENTRATE FEED CONTAINING Indigofera zollingeriana IN GOAT

“…This was due to the high CP content of the plant (29.2% DM). High CP of Indigofera had been also reported by some authors and generally ranged from 23-27% DM (Kaitho et al, 1998;Tscherning et al, 2006;Bhatta et al, 2012;Bhatta et al, 2013). In vitro dry matter (IVDMD) and organic matter digestibility (IVOMD) values of the experimental concentrates were 65.5-71.5% and 63.0-68.1%, respectively, while the in vitro crude protein digestibility (IVCPD) values were 79.1-83.8% (Figure 1).…”