Hops ( L.) Bitter Acids: Modulation of Rumen Fermentation and Potential As an Alternative Growth Promoter.

Antibiotics can improve ruminant growth and efficiency by altering rumen fermentation selective inhibition of microorganisms. However, antibiotic use is increasingly restricted due to concerns about the spread of antibiotic-resistance. Plant-based antimicrobials are alternatives to antibiotics in animal production.

Effects of extracts of Humulus lupulus (hops) and Yucca schidigera applied alone or in combination with monensin on rumen fermentation and microbial populations in vitro.

Background: β-Acids in hops (Humulus lupulus) and saponins in yucca (Yucca schidigera) have been found to possess antimicrobial properties similar to that of monensin and could be an alternative to in-feed antibiotics. The effects of monensin (MON) and ethanol extracts of hops (HE) and Y. schidigera (YE) alone and in combination with MON were assessed on ruminal microbial composition and fermentation in vitro of a barley-based diet.

Effects of California chaparral plants on in vitro ruminal fermentation of forage and concentrate diet.

Background: The combustible nature of chaparral plants has been attributed to the presence of secondary compounds such as phenolic acids, flavonoids and essential oils, among others. However, the implication of the antimicrobial properties of secondary compounds of chaparral in modulating rumen microbial metabolism has not been determined. The effects of 11 chaparral plants on rumen microbial fermentation were assessed in an in vitro batch culture fermentation fed a barley silage:barley grain-based low concentrate (LC) and high concentrate (HC) diets.

Effects of hop varieties on ruminal fermentation and bacterial community in an artificial rumen (rusitec).

Background: There is a growing interest in the use of hops (Humulus lupulus) as an alternative to antibiotics to manipulate ruminal fermentation. However, the effects of different hop varieties on ruminal fermentation and bacterial populations have not been studied. Here the effects of three hop varieties, Cascade (CAS), Millennium (MIL) and Teamaker (TM), at a level of 800 µg mL(-1) inoculum on ruminal fermentation and microbial populations in an artificial rumen system (rusitec) fed a barley silage-based total mixed ration were investigated.

Fermentation, degradation and microbial nitrogen partitioning for three forage colour phenotypes within anthocyanidin-accumulating Lc-alfalfa progeny.

Background: Alfalfa has the disadvantage of having a rapid initial rate of protein degradation, which results in pasture bloat, low efficiency of protein utilisation and excessive nitrogen (N) pollution into the environment for cattle. Introducing a gene that stimulates the accumulation of monomeric/polymeric anthocyanidins might reduce the ruminal protein degradation rate (by fixing protein and/or direct interaction with microbes) and additionally reduce methane emission. The objectives of this study were to evaluate in vitro fermentation, degradation and microbial N partitioning of three forage colour phenotypes (green, light purple-green (LPG) and purple-green (PG)) within newly developed Lc-progeny and to compare them with those of parental green non-transgenic (NT) alfalfa.