Host-mediated effects of phytonutrients in ruminants: A review

Abstract

Plants produce an extensive array of organic compounds derived from secondary metabolism that may be useful in animal nutrition because of their chemical makeup. These plant-derived bioactive compounds, also referred to as phytonutrients (PN) or phytobiotics, have been shown to express antimicrobial activities against a wide range of bacteria, yeast, and fungi and have been investigated as rumen modifiers in ruminant nutrition. Studies have reported that PN may inhibit deamination of AA and methanogenesis in the rumen and shift fermentation toward propionate and butyrate. Most of the experiments, however, have been conducted in vitro, and responses have been highly variable and inconsistent in animal experiments. In addition, some studies have reported that PN had positive effects on productivity, although rumen fermentation was not affected. Other than antimicrobial effects in the gut, PN are known to bind specific receptors expressed in neurons, intestines, and other cells and exhibit related physiological effects in nonruminants. The receptor-mediated effects include immune responses, oxidative stress, and insulin secretion and activity. Some PN, due to their phenolic nature, are likely less susceptible to microbial degradation in the rumen and may exhibit activities postruminally, similar to their mode of action in nonruminant species. This opens a new area of research in ruminants, including effects of PN on the animal's immune system, postruminal nutrient use, and animal physiology. Although limited, studies with ruminants provide first evidence of PN's regulatory effects on the host responses. For example, PN were reported to regulate immune cells related to adaptive and innate immunity in challenged or nonchallenged dairy cows. Supplementation of PN reduced oxidative stress by decreasing lipid peroxidation and increasing endogenous antioxidants in ruminants. Additionally, insulin secretion and sensitivity were reportedly regulated by PN in dairy cows. The regulatory effects of PN on immunity may be beneficial for immune suppression and inflammation in dairy cows. In addition, PN could positively affect energy partitioning for milk production through their effects on insulin secretion and sensitivity. Further research is needed to elucidate the effect and mode of action of PN on immune function and animal energetics.

Effects of 3-nitrooxypropanol on rumen fermentation, lactational performance, and resumption of ovarian cyclicity in dairy cows

“…Unlike the results from the current experiment, Haisan et al (2017) did not observe an effect of 3-NOP on insulin concentration in mid-to late-lactation cows. A review by Oh et al (2017) speculated that a decrease in serum insulin without an effect on plasma glucose concentra-tion may be associated with a positive effect on energy partitioning for production purposes in dairy cows. The decrease in insulin concentration by 3-NOP in our study may have redirected glucose for milk production by lowering glucose uptake in insulin-dependent tissues as skeletal muscle and adipose tissue, as suggested by De Koster and Opsomer (2013).…”

Nutraceuticals

“…Capsaicinoids, bioactive compounds sourced from flowering Capsicum plants, demonstrated an ability to modulate the acute-phase response in dairy cows, including in response to an intravenous lipopolysaccharide (LPS) challenge. 3,98 Furthermore, postruminal supplementation of capsaicinoids increased CD4 1 T-cell proliferation. 97 By potentially affecting both the innate and adaptive branches of the immune system, capsaicinoid supplementation may be particularly beneficial during vaccination events.…”

“…They consist of natural compounds and/or microbes that offer potentially advantageous effects related to ruminant health and productivity, including improved feed efficiency, milk production, and disease resistance through immune modulation or decreased disease pressure. [1][2][3] Nutraceuticals are a broad group of compounds that can be classified in several ways. Some of the more common classifications are based on the mechanism of action, chemical nature, or the feed source of the compound.…”

A multicomponent herbal feed additive improves somatic cell counts in dairy cows ‐ a two stage, multicentre, placebo‐controlled long‐term on‐farm trial

“…Typical herbs present in the diet of cattle grazing on natural pastures contain a broad spectrum of secondary metabolites (phytochemicals), such as various phenolic compounds, essential oils and alkaloids (Cornu et al, 2001;Fraisse et al, 2007;Jayanegara, Marquardt, Kreuzer, & Leiber, 2011). There is evidence that selection behaviour (Villalba, Provenza, & Han, 2004), digestion (Cobellis, Trabalza-Marinucci, & Yu, 2016) and endogenous metabolic processes (McGrath et al, 2018;Oh, Wall, Bravo, & Hristov, 2017) of cattle are adapted to these phytochemicals which represented their biochemical environment during evolution and historical domestication. However, the biochemical composition of contemporary dairy rations is likely to differ from that.…”

“…They all contain high concentrations of crude protein, and easily degradable carbohydrates, but are rather low in phytochemicals. It is not unlikely that with the narrow botanical and biochemical spectrum of these intensive diets important functions of phytochemicals for rumen control (Buccioni, Decandia, Minieri, Molle, & Cabiddu, 2012;Cobellis et al, 2016;Mendel, Chlopecka, Dziekan, & Karlik, 2016), lipid metabolism (Khiaosa-ard et al, 2009;Leiber, Willems, Werne, Ammer, & Kreuzer, 2019), antioxidative protection, immune factors and hormone regulation (Oh et al, 2017) have been lost. The implications of this loss for animal health are not yet sufficiently understood.…”