Coleus amboinicus (Lour.) leaves as a modulator of ruminal methanogenesis and biohydrogenation in vitro.

Active plant metabolites (APM) are recognized as modifiers of ruminal microbial fermentation including methanogenesis and biohydrogenation of fatty acids (FA). Coleus amboinicus Lour. leaves (CAL) are rich in several APM, which could serve as ruminal fermentation modulators. A phytochemical analysis showed that CAL contain phenolic acids (10.4 mg·g-1 dry matter [DM]; high in rosmarinic acid), flavonoids (2.6 mg·g-1 DM), diterpenes (2 mg·g-1 DM), and linolenic acid (35.4 g (100 g)-1 FA). This study aimed to investigate the effect of CAL on ruminal methanogenesis and biohydrogenation as well as basic fermentation characteristics and microbial populations. The in vitro experiment was carried out using Hohenheim gas test system with 40 mL of buffered ruminal fluid incubated for 24 h at 39 °C in anaerobic conditions. Approximately 400 mg (DM basis) of total mixed ration (TMR) was used as a control substrate and the CAL substrate was used at doses of 10, 20, 40, and 80 mg DM replacing equal amounts of TMR. Addition of CAL decreased methane production up to 30% linearly as the amount of CAL increased (P < 0.05). In vitro dry matter digestibility and ammonia tended to increase with increasing doses of CAL. Concentration of total volatile fatty acids was not affected by the CAL although there appeared to be a minor positive linear trend; however, acetate, butyrate, and isobutyrate proportion increased quadratically (P < 0.001). CAL tended to linearly increase α-linolenic acid and conjugated linoleic acid as well as increased stearic acid concentration in buffered ruminal fluid. CAL particularly increased total protozoa and bacterial populations during fermentation, but inhibited methanogens. It is concluded that the CAL may be promising to be used as a feed additive to decrease methanogenesis as well as biohydrogenation of FA in the rumen.

Effects of herbal nutraceuticals and/or zinc against Haemonchus contortus in lambs experimentally infected.

BACKGROUND: The gastrointestinal parasitic nematode Haemonchus contortus is a pathogenic organism resistant to several anthelmintics. This study assessed the efficacy of a medicinal herbal mixture (Herbmix) and organic zinc, as an essential trace element for the proper functioning of both unspecific and specific immune defensive mechanisms, against experimental infections with H. contortus in lambs. All lambs were infected orally with approximately 5000 third-stage larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Twenty-four female lambs 3-4 months of age were divided into four groups: unsupplemented animals (control), animals supplemented with Herbmix (Hmix), animals supplemented with organic zinc (Zn) and animals supplemented with Herbmix and organic zinc (Hmix+Zn). Eggs per gram (EPG) of faeces were quantified 20, 28, 35, 42, 49, 56, 62 and 70 d post-infection and mean abomasal worm counts were assessed 70 d post-infection. Samples of blood were collected from each animal 7, 35, 49 and 70 d post-infection. RESULTS: Quantitative analyses of the bioactive compounds in Herbmix identified three main groups: flavonoids (9964.7 µg/g), diterpenes (4886.1 µg/g) and phenolic acids (3549.2 µg/g). Egg counts in the lambs treated with Hmix, Zn and Hmix+Zn decreased after 49 d. The EPGs in the Zn and Hmix+Zn groups were significantly lower on day 56 (P < 0.05 and P < 0.01, respectively), and the EPGs and mean worm counts were significantly lower on day 70 in all supplemented groups (P < 0.05 and P < 0.01). Hemograms of complete red blood cells of each animal identified clinical signs of haemonchosis after day 35. Serum calprotectin concentrations and IgA levels were significantly affected by treatment. The treatment influenced serum malondialdehyde concentrations (P < 0.05) and sulfhydryl groups (P < 0.01) of antioxidant status. The mineral status was unaltered in all lambs. CONCLUSION: A direct anthelmintic impact on the viability of nematodes was not fully demonstrated, but the treatments with herbal nutraceuticals and zinc likely indirectly contributed to the increase in the resistance of the lambs to nematode infection.