Pasture-finishing of bison improves animal metabolic health and potential health-promoting compounds in meat.

BACKGROUND: With rising concerns regarding the effects of red meat on human and environmental health, a growing number of livestock producers are exploring ways to improve production systems. A promising avenue includes agro-ecological practices such as rotational grazing of locally adapted ruminants. Additionally, growing consumer interest in pasture-finished meat (i.e., grass-fed) has raised questions about its nutritional composition. Thus, the goal of this study was to determine the impact of two common finishing systems in North American bison-pasture-finished or pen-finished on concentrates for 146 d-on metabolomic, lipidomic, and fatty acid profiles of striploins (M. longissimus lumborum). RESULTS: Six hundred and seventy-one (671) out of 1570 profiled compounds (43%) differed between pasture- and pen-finished conditions (n = 20 animals per group) (all, P < 0.05). Relative to pasture-finished animals, the muscle of pen-finished animals displayed elevated glucose metabolites (~ 1.6-fold), triglycerides (~ 2-fold), markers of oxidative stress (~ 1.5-fold), and proteolysis (~ 1.2-fold). In contrast, pasture-finished animals displayed improved mitochondrial (~ 1.3-fold higher levels of various Krebs cycle metabolites) and carnitine metabolism (~ 3-fold higher levels of long-chain acyl carnitines) (all P < 0.05). Pasture-finishing also concentrated higher levels of phenolics (~ 2.3-fold), alpha-tocopherol (~ 5.8-fold), carotene (~ 2.0-fold), and very long-chain fatty acids (~ 1.3-fold) in their meat, while having lower levels of a common advanced lipoxidation (4-hydroxy-nonenal-glutathione; ~ 2-fold) and glycation end-product (N6-carboxymethyllysine; ~ 1.7-fold) (all P < 0.05). In contrast, vitamins B5, B6, and C, gamma/beta-tocopherol, and three phenolics commonly found in alfalfa were ~ 2.5-fold higher in pen-finished animals (all P < 0.05); suggesting some concentrate feeding, or grazing plants rich in those compounds, may be beneficial. CONCLUSIONS: Pasture-finishing (i.e., grass-fed) broadly improves bison metabolic health and accumulates additional potential health-promoting compounds in their meat compared to concentrate finishing in confinement (i.e., pen-finished). Our data, however, does not indicate that meat from pen-finished bison is therefore unhealthy. The studied bison meat-irrespective of finishing practice-contained favorable omega 6:3 ratios (< 3.2), and amino acid and vitamin profiles. Our study represents one of the deepest meat profiling studies to date (> 1500 unique compounds), having revealed previously unrecognized differences in animal metabolic health and nutritional composition because of finishing mode. Whether observed nutritional differences have an appreciable effect on human health remains to be determined.

Nature, nurture, and vegetation management: Studies with sheep and goats.

Diet selection and preference by grazing animals are determined by genetic and environmental factors (i.e., nature and nurture) that interact and affect their efficacy for managing vegetation as targeted grazers. The effect of rearing environment on the consumption of leafy spurge by sheep and goats was investigated. We hypothesized that although rearing environment will affect the preference for chemically defended plants ultimately, the inherent ability to detoxify or eliminate phytotoxins will limit an animal's preference for them. The objective of this study was to determine if sheep would consume more of the invasive weed leafy spurge (Euphorbia esula) if they were raised by goat compared to sheep raised by sheep and goat raised by goat. Sheep were raised on leafy spurge-infested pastures by either their ewe (S) or a goat doe (FS) on which they were fostered within 24 hours of birth and parturition of lamb and doe, respectively. Does that fostered lambs also raised their own goat offspring (G) such that the same doe raised the FS and G animals. The rearing environment's effect on leafy spurge consumption was tested the following growing season by simultaneously grazing all animals on the same leafy spurge-infested rangeland and estimating percentage leafy spurge in their diet with either fecal near-infrared spectroscopy (f.NIR) or bite count. Goats consumed more leafy spurge as determined by either f.NIR (62.8%, P < 0.06) or bite count (71.9%, P < 0.01) than FS (35.2 % f.NIR, 39.3% bite count) or S (10.1 % f.NIR, 18.2% bite count). The FS consumed over twice as much leafy spurge as S and were numerically intermediate to G and S for leafy spurge consumption but not significantly different from the S sheep, most likely because one FS sheep did not eat leafy spurge during the evaluation period. Because leafy spurge is aversive to sheep but not goats, higher leafy spurge consumption by FS sheep is hypothesized to result from inoculation of their rumen microbes with microbes from the does capable of denaturing aversive phytotoxins in leafy spurge. The higher consumption of leafy spurge by G compared to FS shows that genetically determined physiological differences influence an animal's ability to ameliorate phytotoxins and determine the upper limit of an animal's preference for a chemically defended plant. It also indicated that in addition to the animal's genome, the genome of an animal's microbiome, which the mother may influence, can play an important role in diet selection.

A metabolomics comparison of plant-based meat and grass-fed meat indicates large nutritional differences despite comparable Nutrition Facts panels.

A new generation of plant-based meat alternatives-formulated to mimic the taste and nutritional composition of red meat-have attracted considerable consumer interest, research attention, and media coverage. This has raised questions of whether plant-based meat alternatives represent proper nutritional replacements to animal meat. The goal of our study was to use untargeted metabolomics to provide an in-depth comparison of the metabolite profiles a popular plant-based meat alternative (n = 18) and grass-fed ground beef (n = 18) matched for serving size (113 g) and fat content (14 g). Despite apparent similarities based on Nutrition Facts panels, our metabolomics analysis found that metabolite abundances between the plant-based meat alternative and grass-fed ground beef differed by 90% (171 out of 190 profiled metabolites; false discovery rate adjusted p < 0.05). Several metabolites were found either exclusively (22 metabolites) or in greater quantities in beef (51 metabolites) (all, p < 0.05). Nutrients such as docosahexaenoic acid (ω-3), niacinamide (vitamin B3), glucosamine, hydroxyproline and the anti-oxidants allantoin, anserine, cysteamine, spermine, and squalene were amongst those only found in beef. Several other metabolites were found exclusively (31 metabolites) or in greater quantities (67 metabolites) in the plant-based meat alternative (all, p < 0.05). Ascorbate (vitamin C), phytosterols, and several phenolic anti-oxidants such as loganin, sulfurol, syringic acid, tyrosol, and vanillic acid were amongst those only found in the plant-based meat alternative. Large differences in metabolites within various nutrient classes (e.g., amino acids, dipeptides, vitamins, phenols, tocopherols, and fatty acids) with physiological, anti-inflammatory, and/or immunomodulatory roles indicate that these products should not be viewed as truly nutritionally interchangeable, but could be viewed as complementary in terms of provided nutrients. The new information we provide is important for making informed decisions by consumers and health professionals. It cannot be determined from our data if either source is healthier to consume.

Is Grassfed Meat and Dairy Better for Human and Environmental Health?

The health of livestock, humans, and environments is tied to plant diversity-and associated phytochemical richness-across landscapes. Health is enhanced when livestock forage on phytochemically rich landscapes, is reduced when livestock forage on simple mixture or monoculture pastures or consume high-grain rations in feedlots, and is greatly reduced for people who eat highly processed diets. Circumstantial evidence supports the hypothesis that phytochemical richness of herbivore diets enhances biochemical richness of meat and dairy, which is linked with human and environmental health. Among many roles they play in health, phytochemicals in herbivore diets protect meat and dairy from protein oxidation and lipid peroxidation that cause low-grade systemic inflammation implicated in heart disease and cancer in humans. Yet, epidemiological and ecological studies critical of red meat consumption do not discriminate among meats from livestock fed high-grain rations as opposed to livestock foraging on landscapes of increasing phytochemical richness. The global shift away from phytochemically and biochemically rich wholesome foods to highly processed diets enabled 2.1 billion people to become overweight or obese and increased the incidence of type II diabetes, heart disease, and cancer. Unimpeded, these trends will add to a projected substantial increase in greenhouse gas emissions (GHGE) from producing food and clearing land by 2050. While agriculture contributes one quarter of GHGE, livestock can play a sizable role in climate mitigation. Of 80 ways to alleviate climate change, regenerative agriculture-managed grazing, silvopasture, tree intercropping, conservation agriculture, and farmland restoration-jointly rank number one as ways to sequester GHG. Mitigating the impacts of people in the Anthropocene can be enabled through diet to improve human and environmental health, but that will require profound changes in society. People will have to learn we are members of nature's communities. What we do to them, we do to ourselves. Only by nurturing them can we nurture ourselves.

Integrated Crop-Livestock Systems and Water Quality in the Northern Great Plains: Review of Current Practices and Future Research Needs.

Integrated crop-livestock systems hold potential to achieve environmentally sustainable production of crop and livestock products. Although previous studies suggest that integrated crop-livestock systems improve soil health, impacts of integrated crop-livestock systems on water quality and aquatic ecosystems are largely unknown. This review (i) summarizes studies examining surface water quality and soil leachate for management practices commonly used in integrated crop-livestock systems (e.g., no-till, cover crops, livestock grazing) with emphasis on the Northern Great Plains ecoregion of North America, (ii) quantifies management system effects on nutrient and total suspended solids concentrations and loads, and (iii) identifies information gaps regarding water quality associated with integrated crop-livestock systems and research needs in this area. In general, management practices used in integrated crop-livestock systems reduced losses of total suspended solids, nitrogen (N), and phosphorus (P) in surface runoff and soil leachate. However, certain management practices (e.g., no-till or reduced tillage) reduced losses of total N (relative median change = -65%), whereas soluble P losses in runoff increased (57%). Conversely, practices such as grazing increased median total suspended solids (22%), nitrate (45%), total N (85%), and total P (25%) concentrations and loads in surface runoff and aquatic ecosystems. An improved understanding of the interactive effects of integrated crop-livestock management practices on surface water quality and soil leachate under current and future climate scenarios is urgently needed. To close this knowledge gap, future studies should focus on determining concentrations and loads of total suspended solids, N, P, and organic carbon in runoff and soil leachate from integrated crop-livestock systems.

Bovine adipose triglyceride lipase is not altered and adipocyte fatty acid-binding protein is increased by dietary flaxseed.

In this paper, we report the full-length coding sequence of bovine ATGL cDNA and analyze its expression in bovine tissues. Similar to human, mouse, and pig ATGL sequences, bovine ATGL has a highly conserved patatin domain that is necessary for lipolytic function in mice and humans. This suggests that ATGL is functionally intact as a triglyceride lipase in cattle. Tissue distribution of ATGL gene expression was highest in fat and muscle (skeletal and cardiac) tissue, while protein expression was solely detectible in the adipose tissue. The effect of 109 days of flaxseed supplementation on ATGL and adipocyte fatty acid-binding protein (FABP4 or A-FABP, E-FABP or FABP5) expression was examined in Angus steers. Supplemented steers had greater triacylglycerol (TAG) content in the muscle compared with unsupplemented ones. Additionally, supplementation increased A-FABP expression and decreased stearoyl-CoA desaturase 1 (SCD-1) expression in muscle, while total ATGL expression was unaffected. In summary, supplementation of cattle rations with flaxseed increased muscle TAG concentrations attributed in part to increased expression of key enzymes involved in lipid trafficking (A-FABP) and metabolism (SCD-1).

Interactions between Euphorbia esula toxins and bovine ruminal microbes.

Cattle generally avoid grazing leafy spurge (LS; Euphorbia esula), whereas sheep and goats will often eat it. Understanding metabolism of toxic phytochemicals in LS by bovine rumen microflora may help explain why cattle often develop aversions to LS after initially eating it. Toxicity of LS compounds after in vitro fermentation with normal vs. antibiotic-modified bovine rumen digesta was evaluated at different lengths of fermentation. Levels of toxic and aversion-inducing ingenols were determined for fermented and nonfermented mixtures of LS and bovine rumen digesta, and the toxicity of an aversion-inducing extract of LS to rumen microbial species that are common in cattle, sheep, and goats was evaluated. Fermentation of LS with bovine digesta increased the toxicity of extracted compounds. Introduction of neomycin (an antibiotic that preferentially inhibits gram-negative bacteria) into the LS and bovine rumen digesta mixtures did not appear to affect toxicities regardless of fermentation length. Levels of ingenol were observed in LS and bovine digesta mixtures (both fermented and nonfermented) that were consistent with levels of ingenols reported for LS. Finally, a toxic extract of LS had little or no negative effect on the growth of several common species of rumen bacteria. The results indicate that LS is not generally toxic to the ruminal bacteria, but that microbial activity in the rumen may be responsible for enhancing LS toxicity to cattle.