Condensed tannins, novel compounds and sources of variation determine the antiparasitic activity of Nordic conifer bark against gastrointestinal nematodes.

The antiparasitic potential of plants could offer a vital solution to alleviating the costs of gastrointestinal nematode (GIN) infections in ruminant production globally. Leveraging known bioactive molecules, however, is complex, where plant species, extraction processes and seasonality impact bioavailability and efficacy. This study assessed the impact of a comprehensive set of factors on the antiparasitic activity of Norwegian conifers to identify bark compounds specific against GIN. Antiparasitic activity was determined using in vitro assays targeting morphologically distinct life stages of ovine GIN: the egg hatch assay and larval motility assay. In depth characterisation of the chemical composition of the bark extracts was carried out using chromatographic separation, UV-absorbance, and molecular mass profiles to identify compounds implicated in the activity. Three key findings emerged: (1) the activity of bark extracts varied markedly from 0 to 100% antiparasitic efficacy, owing to tree species, extraction solvent and seasonality; (2) the GIN exhibited species-and stage-specific susceptibility to the bark extracts; (3) the presence of condensed tannins, amongst other compounds, was associated with anthelmintic activity. These findings add new insights into urgently needed alternative parasite control strategies in livestock.

Effect of grassland cutting frequency, species mixture, wilting and fermentation pattern of grass silages on in vitro methane yield.

Mitigating enteric methane (CH4) emissions is crucial as ruminants account for 5% of global greenhouse gas emissions. We hypothesised that less frequent harvesting, use of crops with lower WSC concentration, ensiling at low crop dry matter (DM) and extensive lactic acid fermentation would reduce in vitro CH4 production. Timothy (T), timothy + red clover mixture (T + RC) or perennial ryegrass (RG), cut either two or three times per season, was wilted to 22.5% or 37.5% DM and ensiled with or without formic acid-based additive. Silages were analysed for chemical composition and fermentation products. In vitro CH4 production was measured using an automated gas in vitro system. Methane production was, on average, 2.8 mL/g OM lower in the two-cut system than in the three-cut system (P < 0.001), and 1.9 mL/g OM lower in T than in RG (P < 0.001). Silage DM did not affect CH4 production (P = 0.235), but formic acid increased CH4 production by 1.2 mL/g OM compared to the untreated silage (P = 0.003). In conclusion, less frequent harvesting and extensive silage fermentation reduce in vitro CH4 production, while RG in comparison to T resulted in higher production of CH4.

Comparative analysis of the anthelmintic efficacy of European heather extracts on Teladorsagia circumcincta and Trichostrongylus colubriformis egg hatching and larval motility.

BACKGROUND: Gastrointestinal nematode (GIN) control is traditionally achieved with the use of anthelmintic drugs, however due to regulations in organic farming and the rise in anthelmintic resistance, alternatives are sought after. A promising alternative is the use of bioactive plant feeding due to the presence of plant secondary metabolites (PSMs) such as proanthocyanidins (PAs). This study focussed on the perennial shrub heather (Ericaceae family), a plant rich in PAs, highly abundant across Europe and with previously demonstrated anthelmintic potential. METHODS: In vitro assays were used to investigate heather's anthelmintic efficacy against egg hatching and larval motility. Heather samples were collected from five European countries across two seasons, and extracts were tested against two GIN species: Teladorsagia circumcincta and Trichostrongylus colubriformis. Polyphenol group-specific ultraperformance liquid chromatography-tandem mass spectrometry analysis was performed to identify relevant polyphenol subgroups present, including the PA concentration and size and ratio of the subunits. Partial least squares analysis was performed to associate efficacy with variation in PSM composition. RESULTS: Heather extracts reduced egg hatching of both GIN species in a dose-dependent manner by up to 100%, while three extracts at the highest concentration (10 mg/ml) reduced larval motility to levels that were not significantly different from dead larvae controls. PAs, particularly the procyanidin type, and flavonol derivatives were associated with anthelmintic activity, and the particular subgroup of polyphenols associated with the efficacy was dependent on the GIN species and life stage. CONCLUSIONS: Our results provide in vitro evidence that heather, a widely available plant often managed as a weed in grazing systems, has anthelmintic properties attributed to various groups of PSMs and could contribute to sustainable GIN control in ruminant production systems across Europe.

Administration of spruce bark (Picea abies) extracts in young lambs exhibits anticoccidial effects but reduces milk intake and body weight gain.

BACKGROUND: Eimeria spp. are widespread apicomplexan parasites known to cause coccidiosis in livestock, resulting in reduced animal welfare and productivity, particularly in sheep. The treatment options are limited, and there is an emerging development of resistance against registered pharmaceuticals. Spruce bark is rich in plant secondary metabolites (PSM), such as condensed tannins, which are bioactive compounds previously shown to have antiparasitic activity. Here, we examined the anticoccidial properties of bark extract of Norway spruce (Picea abies) against a field isolate of ovine Eimeria spp. by treating Eimeria-infected pre-ruminant lambs with water-extracted bark daily for 12 days. We hypothesised that the bark extract would reduce the faecal oocyst excretion and, consequently, the severity of diarrhoea. RESULTS: Oral administration of spruce bark extract significantly reduced the excretion of Eimeria oocysts in milk-fed lambs post treatment till the end of the trial 22 days post infection. This difference in oocyst excretion between the treated and the untreated infected animals increased with time. Compared to the untreated and the sham-infected control group, the group treated with bark extract had softer faeces and reduced milk intake during the treatment period. After discontinuing the treatment, the treated animals got a more solid and formed faeces compared to that of the untreated control group, and the milk intake increased to the level of the sham-infected, untreated control group. The bark extract treated animals had a lower body weight and a lower mean daily body weight gain throughout the whole duration of the experiment. CONCLUSIONS: Bark extract from Norway spruce showed marked anticoccidial properties by reducing the faecal oocyst count and associated diarrhoea in young lambs. Simultaneously we experienced detrimental effects of the treatment, displayed as reduced feed intake and daily body weight gain. Therefore, we suggest conducting similar studies with lower bark extract dosage to explore the possibilities of a better trade-off to reduce the negative impact while maintaining the antiparasitic effect.

Extracts of pine bark (Pinus sylvestris) inhibit Cryptosporidium parvum growth in cell culture.

The widespread apicomplexan parasite Cryptosporidium parvum is responsible for severe gastrointestinal disease in humans and animals. The treatment options are limited, and the efficacy of available drugs is low. Bark contains condensed tannins (CT), which are bioactive compounds previously shown to inhibit parasite development. Here, we examined the anti-cryptosporidial properties of bark extract of Scots pine (Pinus sylvestris) against C. parvum by means of an in vitro growth inhibition test. We hypothesised that bark extracts would have dose-dependent inhibitory effects on the development of C. parvum in cell culture.Bark extracts from Scots pine extracted with acetone, methanol, and water as solvents were investigated using human colorectal adenocarcinoma cells infected with C. parvum. Oocysts were inoculated onto the cell monolayer and bark extract was added at seven different concentrations. Parasite growth inhibition was quantified by qPCR.The acetone and methanol extracts demonstrated a sigmoid dose-dependent inhibition of C. parvum. The IC50 values were 244.6 and 279.1 µg dry matter extract/mL, and 25.4 and 24.1 µg CT/mL, for acetone and methanol extracts, respectively. The IC50 for both extracts were similar, both with regard to the dry matter concentration of each extract and to CT concentrations.Given the limited treatment options available for Cryptosporidium spp., the evidence generated in our study encourages further investigation into the in vitro and in vivo effects of pine bark extracts against C. parvum.

Chemical Analysis and Anthelmintic Activity Against Teladorsagia Circumcincta of Nordic Bark Extracts In vitro.

Helminth parasitic infections are common in small ruminants in Norway; infection is usually treated with anthelmintic drugs, but anthelmintic resistance is an increasing problem. It is necessary to identify strategies to reduce the use of anthelmintic drugs and mitigate the impact of anthelmintic resistance. Condensed tannin (CT)-rich forages have been shown to reduce the helminth burden in small ruminants, but these forages have limited cultivation potential in Scandinavia. A good source for CT in cold climatic regions may be the bark of several commercially utilized tree species. In the present study, we determined the content and characterized the type of CT in bark extracts of pine (Pinus sylvestris L.), spruce (Picea abies L.), and birch (Betula pubescens). Extracts of selected bark samples were tested for their anthelmintic efficacy against the ovine infectious nematode Teladorsagia circumcincta. Total CT content was higher in the bark from younger (10-40 years old) pine and spruce trees; it decreased with tree age in pine, whereas it remained relatively stable in the bark of spruce and birch. Pine trees consisted of 100% procyanidins, whereas prodelphinins were present in most spruce (4-17%) and all birch samples (5-34%). Our studies clearly showed that there is variation in the anthelmintic activity of water and acetone extracts of bark samples collected from various sites around Norway, as this was measured with two independent in vitro assays, the egg hatch and larvae motility assays. The anthelmintic activity of some extracts was consistent between the two assays; for example, extracts from the three samples with the highest CT content showed very high activity in both assays, whereas the extract from the sample with the lowest CT content showed the lowest activity in both assays. For other extracts, activity was not consistent across the assays, which could be attributed to the susceptibility of the different stages of the parasitic life cycle. We demonstrated that bark extracts from commercially used trees in Scandinavia have the potential to be used as alternatives to anthelmintics. Further work should focus on refining the associations between bark extracts and anthelmintic activity to identify the best strategies to reduce the input of anthelmintic drugs in livestock production systems.

Differing responses in milk composition from introducing rapeseed and naked oats to conventional and organic dairy diets.

Dairy products are often considered challenging for health due to their saturated fatty acid content, yet they also provide beneficial nutrients, some unique to ruminants. The degree of fat saturation is influenced by cows' diets; grazing pasture enhances unsaturated fatty acids in milk compared with conserved forages. These benefits can be partially mimicked by feeding oilseeds and here we consider the impact on milk composition in a 2 × 2 trial, feeding rapeseed to both conventional and organic cows, finding very differing lipid metabolism in the 4 experimental groups. For milk fat, benefits of organic rather than conventional management (+39% PUFA, +24% long chain omega-3 and +12% conjugated linoleic acid (CLA)) appear complementary to those from feeding rape (+43% MUFA, +10% PUFA, +40% CLA), combining to produce milk 16% lower SFA and higher in MUFA (43%), PUFA (55%) and CLA (59%). Organic and rape feeding provide less omega-3 PUFA than the conventional and control diets, yet contrary to expectations, together they almost doubled (+94%) the omega-3 concentration in milk, implying a 3.8 fold increase in net transfer from diet into milk. Organic and rape feeding also gave lower trace-elements and antioxidants in milk. Greater understanding of these phenomena might enhance the sustainability of dairying.

Higher PUFA and n-3 PUFA, conjugated linoleic acid, α-tocopherol and iron, but lower iodine and selenium concentrations in organic milk: a systematic literature review and meta- and redundancy analyses.

Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. However, there is still considerable uncertainty over whether the use of organic production standards affects milk quality. Here we report results of meta-analyses based on 170 published studies comparing the nutrient content of organic and conventional bovine milk. There were no significant differences in total SFA and MUFA concentrations between organic and conventional milk. However, concentrations of total PUFA and n-3 PUFA were significantly higher in organic milk, by an estimated 7 (95 % CI -1, 15) % and 56 (95 % CI 38, 74) %, respectively. Concentrations of α-linolenic acid (ALA), very long-chain n-3 fatty acids (EPA+DPA+DHA) and conjugated linoleic acid were also significantly higher in organic milk, by an 69 (95 % CI 53, 84) %, 57 (95 % CI 27, 87) % and 41 (95 % CI 14, 68) %, respectively. As there were no significant differences in total n-6 PUFA and linoleic acid (LA) concentrations, the n-6:n-3 and LA:ALA ratios were lower in organic milk, by an estimated 71 (95 % CI -122, -20) % and 93 (95 % CI -116, -70) %. It is concluded that organic bovine milk has a more desirable fatty acid composition than conventional milk. Meta-analyses also showed that organic milk has significantly higher α-tocopherol and Fe, but lower I and Se concentrations. Redundancy analysis of data from a large cross-European milk quality survey indicates that the higher grazing/conserved forage intakes in organic systems were the main reason for milk composition differences.

Composition differences between organic and conventional meat: a systematic literature review and meta-analysis.

Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectively. However, for these and many other composition parameters, for which meta-analyses found significant differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Evidence from controlled experimental studies indicates that the high grazing/forage-based diets prescribed under organic farming standards may be the main reason for differences in FA profiles. Further studies are required to enable meta-analyses for a wider range of parameters (e.g. antioxidant, vitamin and mineral concentrations) and to improve both precision and consistency of results for FA profiles for all species. Potential impacts of composition differences on human health are discussed.

Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans.

Effect of crop protection and fertilization regimes used in organic and conventional production systems on feed composition and physiological parameters in rats.

Very little is known about the effects of an organic or conventional diet on animal physiology and health. Here, we report the effect of contrasting crop protection (with or without chemosynthetic pesticides) and fertilization (manure or mineral fertilizers) regimes on feed composition and growth and the physiological parameters of rats. The use of manure instead of mineral fertilizers in feed production resulted in lower concentrations of protein (18.8 vs 20.6%) and cadmium (3.33 vs 4.92 µg/100 g) but higher concentrations of polyphenols (1.46 vs 0.89 g/100 g) in feeds and higher body protein (22.0 vs 21.5%), body ash (3.59 vs 3.51%), white blood cell count (10.86 vs 8.19 × 10³/mm³), plasma glucose (7.23 vs 6.22 mmol/L), leptin (3.56 vs 2.78 ng/mL), insulin-like growth factor 1 (1.87 vs 1.28 µg/mL), corticosterone (247 vs 209 ng/mL), and spontaneous lymphocyte proliferation (11.14 vs 5.03 × 10³ cpm) but lower plasma testosterone (1.07 vs 1.97 ng/mL) and mitogen stimulated proliferation of lymphocytes (182 vs 278 × 10³ cpm) in rats. There were no main effects of crop protection, but a range of significant interactions between fertilization and crop protection occurred.

Effect of feeding intensity and milking system on nutritionally relevant milk components in dairy farming systems in the North East of England.

There is increasing concern that the intensification of dairy production reduces the concentrations of nutritionally desirable compounds in milk. This study therefore compared important quality parameters (protein and fatty acid profiles; α-tocopherol and carotenoid concentrations) in milk from four dairy systems with contrasting production intensities (in terms of feeding regimens and milking systems). The concentrations of several nutritionally desirable compounds (ß-lactoglobulin, omega-3 fatty acids, omega-3/omega-6 ratio, conjugated linoleic acid c9t11, and/or carotenoids) decreased with increasing feeding intensity (organic outdoor ≥ conventional outdoor ≥ conventional indoors). Milking system intensification (use of robotic milking parlors) had a more limited effect on milk composition, but increased mastitis incidence. Multivariate analyses indicated that differences in milk quality were mainly linked to contrasting feeding regimens and that milking system and breed choice also contributed to differences in milk composition between production systems.

Prevalence of Anaplasma phagocytophilum infection and effect on lamb growth.

BACKGROUND: A major challenge in sheep farming during the grazing season along the coast of south-western Norway is tick-borne fever (TBF) caused by the bacteria Anaplasma phagocytophilum that is transmitted by the tick Ixodes ricinus. METHODS: A study was carried out in 2007 and 2008 to examine the prevalence of A. phagocytophilum infection and effect on weaning weight in lambs. The study included 1208 lambs from farms in Sunndal Ram Circle in Møre and Romsdal County in Mid-Norway, where ticks are frequently observed. All lambs were blood sampled and serum was analyzed by an indirect fluorescent antibody assay (IFA) to determine an antibody status (positive or negative) to A. phagocytophilum infection. Weight and weight gain and possible effect of infection were analyzed using ANOVA and the MIXED procedure in SAS. RESULTS: The overall prevalence of infection with A. phagocytophilum was 55%. A lower weaning weight of 3% (1.34 kg, p < 0.01) was estimated in lambs seropositive to an A. phagocytophilum infection compared to seronegative lambs at an average age of 137 days. CONCLUSIONS: The results show that A. phagocytophilum infection has an effect on lamb weight gain. The study also support previous findings that A. phagocytophilum infection is widespread in areas where ticks are prevalent, even in flocks treated prophylactic with acaricides.

A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds.

BACKGROUND: It has been questioned if the old native Norwegian sheep breed, Old Norse Sheep (also called Norwegian Feral Sheep), normally distributed on coastal areas where ticks are abundant, is more protected against tick-borne infections than other Norwegian breeds due to a continuously high selection pressure on pasture. The aim of the present study was to test this hypothesis in an experimental infection study. METHODS: Five-months-old lambs of two Norwegian sheep breeds, Norwegian White (NW) sheep and Old Norse (ON) sheep, were experimentally infected with a 16S rRNA genetic variant of Anaplasma phagocytophilum (similar to GenBank accession number M73220). The experiment was repeated for two subsequent years, 2008 and 2009, with the use of 16 lambs of each breed annually. Ten lambs of each breed were inoculated intravenously each year with 0.4 ml A. phagocytophilum-infected blood containing approximately 0.5 × 106 infected neutrophils/ml. Six lambs of each breed were used as uninfected controls. Half of the primary inoculated lambs in each breed were re-challenged with the same infectious dose at nine (2008) and twelve (2009) weeks after the first challenge. The clinical, haematological and serological responses to A. phagocytophilum infection were compared in the two sheep breeds. RESULTS: The present study indicates a difference in fever response and infection rate between breeds of Norwegian sheep after experimental infection with A. phagocytophilum. CONCLUSION: Although clinical response seems to be less in ON-lambs compared to NW-lambs, further studies including more animals are needed to evaluate if the ON-breed is more protected against tick-borne infections than other Norwegian breeds.

High nitrogen costs of dairy production in Europe: worsened by intensification.

Intensification of agriculture has been proposed as one way of minimizing emissions per unit of product, apparently legitimizing the ongoing structural changes in agriculture. We have investigated the relationship between the farming intensity and the nitrogen (N) dissipation by calculating the overall N emission factor (E: total N surplus per unit of N in the produce) from several studies of dairy farms, covering a wide range of environments and production intensities. Fundamental steps were (1) the distinction between trophic levels, mineral, plant and animal N; and (2) the inclusion of N losses related to bought feed. The results show that E increases significantly with the production intensity of the dairy farm. The tradition for separate optimization of the animal and crop sectors may be a reason. We suggest that the N pollution can be mitigated by more extensive farming, both by re-coupling crop and animal production side by side, and by keeping land under cultivation when production is reduced.