This study assessed the influence of green tea powder diet supplementation on performance, nutrient utilisation, caecal microbiota profile and meat quality in broiler chickens. A total of 144, one-day-old broiler (Ross 308) chicks were allocated to 18 cages (eight broilers/cage) which were randomly assigned to one of three dietary treatments: a wheat-based basal diet or supplemented with one of two types of green tea; normal (N-GT) or selenium-rich (Se-GT) tea, at an inclusion rate of 1%. Bird performance, nitrogen-corrected apparent metabolisable energy (AMEn), and total tract digestibility of fat and starch were measured on d 7, 21 and 35. Effects on microbiota profile on d 7, 21 and 35 were determined in a cohort study. Green tea supplementation reduced (P<0.05) the weight gain and feed intake but improved (P<0.05) feed efficiency. Supplementation with N-GT increased the AMEn on d 7 and 21, and with Se-GT on d 7 (P<0.05). AMEn increased with age for all treatments. Fat digestibility increased (P<0.05) in birds fed N-GT on d 21 and Se-GT on d 7 and 21. Starch digestibility increased (P<0.05) on d 21 with N-GT supplementation and on d 7 with Se-GT supplementation. Carcass and breast meat yields were unaffected (P<0.05) by the dietary treatments. The abdominal fat pad decreased (P<0.05) in the N-GT diet and numerically in the Se- GT diet. Drip loss was less in meat from birds (P<0.05) fed both green tea treatments. Cooking loss was reduced in the Se-GT treatment (P<0.05). Dietary inclusion of green tea powder positively influenced microbiota profile, with increased (P<0.05) numbers of beneficial bacteria (Lactobacillus spp. and Bifidobacterium spp.) and reduced (P<0.05) numbers of pathogenic bacteria (Clostridium spp. and Bacteroides spp.). Differences were observed between the two green tea types, with Se-GT being more beneficial than N-GT in the positive modulation of intestinal microbiota.

The present study was conducted to assess the influence of green tea supplementation on performance, nutrient utilisation and cecal microbiota of broiler chickens. Treatments consisted of a wheat-based basal diet and the basal diet supplemented with one of two types of green tea, namely normal (N-GTE) or selenium-rich (Se-GTE) at an inclusion rate of 1%. Bird performance, nitrogen-corrected apparent metabolizable energy (AMEn), and total tract digestibility of fat and starch were measured on d 7, 21 and 35. In addition, effects on cecal microbiota counts were determined in a cohort study. Green tea supplementation lowered (P < 0.05) weight gain and feed intake, but improved feed per gain (P < 0.05). Supplementation with N-GTE increased the AMEn on d 7 and 21, and with Se-GTE on d 7 (P < 0.05). AMEn increased with age for all treatments. Fat digestibility increased with N-GTE supplementation on d 21 and with Se-GTE supplementation on d 7 and 21 (P <0.05). Starch digestibility increased on d 21 with N-GTE supplementation and on d 7 with Se-GTE supplementation (P < 0.05). The abdominal fat pad, as a proportion of carcass weight, decreased in the Se-GTE diet (P < 0.05) and numerically in the N-GTE diet. Drip losses were lowered (P < 0.05) by both GTE treatments. There was no difference in cooking losses and breastmeat yield between treatments. Dietary inclusion of green tea had a positive effect on the cecal microbiota, with an increased (P < 0.05) number of beneficial bacteria (Lactobacillus spp. and Bifidobacterium spp.) and a reduced (P < 0.05) number of pathogenic bacteria (Clostridium spp and Bacteroides spp.). Differences were observed between the two green tea types, with Se-GTE being more beneficial than N-GTE in the positive modulation of gut microbiota.

Anthocyanins are the most abundant phytochemicals found in blueberries and exhibit several biological properties including antioxidant activity. This study investigated total anthocyanin concentration, chlorogenic acid concentration, antioxidant activity using FRAP assay and anti-angiogenic activity of five rabbiteye blueberry varieties ('Centurion', 'Maru', 'Rahi', 'Ono', 'Tifblue'). 'Tifblue' showed the highest total anthocyanin and chlorogenic acid concentrations while 'Rahi' contained the lowest. Interestingly, antioxidant activity was better correlated with chlorogenic acid concentration than anthocyanin. Anti-angiogenic properties of blueberry extracts were determined by chicken chorioallantoic membrane (CAM) assay. Blueberry extracts had macroscopic effects on CAM which were measured both quantitatively and qualitatively. In control CAM, a blood vessel network was formed with fine capillaries while there were fewer, shorter & more branched capillaries in blueberry extract treated CAMs. Even though some blood vessels or capillaries in the blueberry-treated CAMs were elongated, the vessels largely failed to interconnect to form a network. Three varieties, 'Centurion', 'Maru' and 'Tifblue', had the strongest anti-angiogenic impact. The best correlation between composition and anti-angiogenic activity was found with anthocyanin concentration rather than antioxidant activity. Blueberries contain various phytochemicals which contribute to their high antioxidant activity. It is well accepted that berry antioxidant activity plays an important role in the prevention of several diseases. However, this study demonstrated that blueberries exhibited other biological activity that is not necessarily related to their antioxidant activity but may have a role in disease prevention. Moreover, different phytochemicals are responsible for different biological activities. (c) All Rights Reserved

A study was conducted to assess the effect of whole wheat (WW) feeding on performance, gizzard development, oocyst yield and intestinal lesion score of broilers challenged with Eimeria species. Diets (ground wheat (GW) and 300 g/kg WW replacing GW before or after pelleting) were offered ad libitum from day 1 or days 7-28 post-hatch. At 21 days of age, each dietary treatment was divided into two groups, one unchallenged control and the other inoculated with mixed species of coccidia (Eimeria acervulina, E. maxima and E. tenella). The results showed that heavier gizzards and higher mortality were observed in WW-fed birds in comparison to GW-fed birds. Interestingly, the pattern of mortality in different dietary treatments paralleled changes in gizzard size. Based on increased mortality, it is concluded that WW feeding exacerbated the severity of coccidiosis infection, possibly via a mechanism involving enhanced gizzard development.

The objective of the present study was to examine the effects of feeding coarsely ground corn on performance, digestive tract measurements, nutrient utilization, and cecal microflora counts in broilers. Five diets containing 600 g/kg of finely ground corn (hammer milled) or 150, 300, 450, and 600 g/kg of coarse corn (cracked in roller mill) replacing (wt/wt) finely ground corn were formulated. Each diet in mash form was offered ad libitum to 6 replicate cages of broilers (8 birds per cage) from d 11 to 35 posthatch. Weight gain increased (linear effect, P < 0.01) with increasing inclusion levels of coarse corn. Feed intake (quadratic effect, P < 0.05) increased at 150 g/kg of coarse corn inclusion, plateaued until 450 g/kg, and then increased again to 600 g/kg. Feed per gain increased (quadratic effect, P < 0.05) as inclusion of coarse corn increased to 300 g/kg and then decreased with further inclusion. Apparent metabolizable energy and total tract DM retention (quadratic effect, P < 0.01) was unaffected up to 300g/kg inclusion, and then decreased with further inclusion of coarse corn. Relative gizzard weight increased (linear effect, P < 0.05) with increasing inclusion of coarse corn. Inclusion of coarse corn had no effect (P > 0.05) on ileal digestibility of DM, N, and starch. Breast meat yield decreased (linear effect, P < 0.05 and abdominal fat increased (linear effect, P < 0.001) with increasing inclusion levels of coarse corn, but there was no effect (P > 0.05) on the carcass yield. A linear (P < 0.05) effect was observed for cecal microflora counts. Lactobacillus spp. and Bifidobacteria spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of coarse corn. The present data showed that feeding of coarse corn increased weight gain and gizzard size, and modified gut microflora profile toward beneficial species and that it can totally replace ground corn in broilers fed mash diets.

The objective of the present study was to examine the effects of prepelleting inclusion of graded levels of whole corn on performance, digestive tract measurements, nutrient utilization, and cecal microbiota in broiler starters. Five diets, containing 600 g/kg of ground corn or 150, 300, 450, and 600 g/kg of whole corn replacing (wt/wt) ground corn, were formulated and cold-pelleted at 65°C. Each diet was offered ad libitum to 6 replicates (8 birds per replicate cage) from d 1 to 21 posthatch. The proportion of coarse particles (>1 mm) increased with increasing prepelleting inclusion of whole corn. Pellet quality, measured as pellet durability index, increased (quadratic effect, P < 0.001) with the inclusion of whole corn to 450 g/kg and then plateaued. Weight gain and feed intake decreased (linear effect, P < 0.001) with increasing prepelleting inclusion of whole corn. Feed per gain (quadratic effect, P < 0.05) increased as the inclusion level of whole corn increased to 300 g/kg and then plateaued with further inclusions. Relative gizzard weight (quadratic effect, P < 0.05) increased with increasing inclusion of whole corn up to 300 g/kg and then levelled off. The AME (quadratic effect, P < 0.05) increased up to 300 g/kg of whole corn inclusion and then decreased with further inclusion. Apparent ileal digestibility of DM (P < 0.001), N (linear effect, P = 0.07), and starch (linear effect, P < 0.001) increased with increasing inclusion levels of whole corn. Based on the fluorescence in situ hybridization method, a linear (P < 0.05) effect was determined for cecal microbiota numbers. Lactobacillus spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of whole corn. The present data showed that, despite increased gizzard weight and nutrient utilization, weight gain of broilers was poorer with prepelleting inclusion of whole corn due to reductions in the feed intake.

Chillies are good sources of phytochemical compounds. The concentration of these compounds varies depending on the genotype, harvest maturity, location within the fruit, the conditions during growth and postharvest handling. Commercially, chilli fruit are harvested by size, resulting in a high variation of fruit age and potentially phytochemical content. To control the maturity of chilli fruit, Jalapeno chillies were tagged at flowering and later harvested at different days after flowering to study the antioxidant capacity as a function of fruit development. Two assays, the ferric reducing antioxidant power (FRAP) assay and scavenging of diphenyl-picrylhydrazyl (DPPH) radicals were used to assess the antioxidant activity while the Folin-Ciocalteu assay was used to measure total polyphenol content (TPC). Two extraction solvents (water and 50% ethanol in water) were tested. The FRAP values significantly increased (P<0.01) in water extracts as the fruit matured on the plant from 1 to 6 weeks after flowering. In contrast, maturity had no influence on TPC or DPPH in either solvent. Both FRAP and TPC values were significantly lower (P<0.01) in ethanol extracts than in water extracts. The antioxidant activity as measured by FRAP assay correlated positively with the TPC in both extracts indicating that the polyphenols may be the major contributors of the antioxidant activity. Overall, maturity at harvest of Jalapeno chilli is an important factor for health-beneficial properties with fully mature fruit (i.e., 6 weeks after flowering) having the highest antioxidant activity measured by FRAP assay.

Tea polyphenols possess antioxidant properties and have been shown to have a protective effect against several degenerative diseases. The study aimed to determine the amounts of polyphenols and antioxidant properties for teas grown in Sri Lanka, over a period of 10months. Water extracts of freeze-dried fresh (unfermented) and fully-fermented tea leaves were made for a structured set of samples (fermented and unfermented teas from six plantations; teas representing two harvesting seasons from four plantations) collected from the main tea growing regions in Sri Lanka. Total phenolic content (TPC), the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity were determined for each sample. The results highlight significant (P<0.05) variations in antioxidant activity across the six plantations. FRAP and DPPH for both fermented and unfermented teas from the four highland plantations showed a significant (P<0.05) interaction between season and plantation. A similar interaction between season and plantation was observed for total phenolics in unfermented teas from the four highland plantations. The variability of the total phenolics for fermented teas, however, was independent of seasonal variations. A significant correlation (r=0.5, P<0.05) was observed between FRAP and total phenolics.

The effects of selenium-containing green tea (SGT; 1.4mgselenium/kg) and China green tea (CGT; 0.13mgselenium/kg) on the in vitro growth of lactobacilli and bifidobacteria were investigated using pure and mixed cultures. SGT had significantly higher phenolic contents (TPC), higher reducing activity, higher DPPH free-radical scavenging activity, and higher ferrous-ion chelating activity (P<0.05–0.0001) than CGT. The addition of aqueous extracts from CGT to Mann-Rogosa-Sharpe (MRS) broth at 10% and 25% (v/v) resulted in small but nonsignificant (P>0.05) increases in the numbers of Lactobacillus rhamnosus and Bifidobacterium breve over the control incubations (without tea). Addition of 10% and 25% of SGT extract resulted in a significant increase (P< 0.05–0.0001) in the number of lactobacilli and bifidobacteria recovered from batch fermentation while CGT did not increase the number of bifidobacteria. The higher prebiotic activity of SGT over CGT may be related to the higher TPC or minerals, notably selenium or a combination of these factors. To test whether selenium itself has an effect on bacterial growth, Na-selenite and Na-selenate were added alone or in combination with CGT to the MRS broth containing pure culture of L. rhamnosus. Growth of this bacterium was enhanced relative to the control incubation of MRS only. When added in combination with CGT, Na-selenate was more effective at enhancing the growth of L. rhamnosus than Na-selenite. The prebiotic effect of SGT could be largely explained by its selenium content.

Dock (Rumex obtusifolius) is commonly regarded as a weed, but it prevents bloat in cattle and the condensed tannins (CT) in dock are able to reduce the viability of gastrointestinal parasite eggs and larvae under in vitro conditions. These benefits, with other attributes of CT from a variety of forages promoted this study to examine effects of CT extracted from dock on the growth of five strains of proteolytic rumen bacteria in vitro. Streptococcus bovis NCFB 2476, Eubacterium sp. C124b, Prevotella bryantii B14, Butyrivibrio fibrisolvens H17c and Clostridium proteoclasticum B316(T) were tested against 200, 400 and 600 mu g CT/ml. In the absence of CT, all bacterial strains showed typical growth and reached maximum optical density (OD 600 nm) after 6 - 8 h of incubation at 39 degrees C. All strains continued to grow in the presence of 200 mu g of the CT from dock per ml but attained significantly lower (P<0.001) OD 600 nm values than their counterparts in the control incubation. The addition of 400 and 600 mu g CT/ml reduced (P<0.001) the growth of all bacterial strains tested compared to controls. All strains except P bryantii did not initiate growth after the addition of 600 mu g/ml relative to the growth before addition of CT. C. proteoclasticum was the most sensitive to the action of CT followed by B. fibrisolvens, S. bovis, Eubacterium sp. and P bryantii. These results suggest that the dock CT have the ability to modify the growth of rumen proteolytic bacteria either directly or indirectly by preventing access to the protein.

Water extracts of two blueberry cultivars (‘Centurion’ and ‘Maru’) were tested for their ability to modify appetite in a rat model. The fruits of ‘Centurion’ had higher in vitro antioxidant capacity (as measured using the ferric reducing antioxidant power (FRAP) assay) and higher total phenolic content (TPC, as measured by the Folin–Ciocalteu method) than fruits of ‘Maru’. When rats were gavaged with water-soluble blueberry extract (BBE; 1ml/day) of both cultivars for 6 days, serum FRAP increased significantly when compared to water-gavaged controls, indicating that BBE may have the ability to elevate circulating antioxidant potentials in vivo. Both cultivars had a satiating influence on experimental rats, as evidenced by their ability to decrease food intake by 8.6% (‘Maru’) and 6.2% (‘Centurion’), although a statistically significant decrease over the control rats was achieved only for the ‘Maru’ treatments. In addition, body weight gain of rats gavaged with extracts from ‘Maru’ and ‘Centurion’ cultivars decreased by 9.2% and 5.3% relative to the rats in the control group, respectively. The reduction in food intake over a 4h period compared to a control treatment preloaded with the same volume of water suggests that the decrease in food intake was mainly a consequence of a satiating effect, rather than a stomach distension effect. The observed results suggest that the reduction in food intake and decrease in body weight in experimental animals is not merely a consequence of antioxidant mechanisms. BBE may provide a good satiety inducer and weight management modulator.

Aim: To assess the in vivo anthelmintic activity of condensed tannins (CT) in the forage species Dorycnium rectum and Medicago sativa, and in an extract from grape (Vitus vinifera) seeds (GSE), against two species of parasite, Teladorsagia (Ostertagia) circumcincta and Trichostrongylus colubriformis, at different stages of their life cycle, in sheep that were parasite-naive or previously exposed to nematodes.Methods: In Trial 1, a factorial treatment structure was used to compare faecal nematode egg counts (FEC) and worm burdens in 40 weaned Romney lambs fed either the CT-containing forage D. rectum (12% dry matter; DM) or M. sativa (lucerne; 0.2% DM). Twenty naive and 20 previously-exposed lambs were drenched free of parasites then reinfected with known species and numbers of parasites, and housed in pens indoors on a diet of lucerne pellets and chaffed hay. Groups of lambs (n=5 lambs per group) were fed one of the forages over one of two time periods within the parasite's life cycle. Six to nine days after the last feeding of fresh forages, faecal samples were collected for FEC, and all lambs were slaughtered and worm counts conducted. In Trial 2, 12 Suffolk x Romney lambs were surgically implanted with an abomasal cannula and then housed indoors in metabolism crates. After infection with parasites, six lambs were infused continuously over a 14-day period with a commercially available CT GSE (96% DM, made up to 34 g/L in water); the remaining lambs were infused with water. During infusion, samples were collected for egg hatch and larval development assays. After infusion, samples were collected for FEC, and all lambs were slaughtered and worm counts conducted.Results: In Trial 1, there was a significant (p < 0.001) difference in burdens of O. circumcincta between naive lambs and those previously exposed to parasites, but no other differences were recorded.In Trial 2, lambs infused with GSE had significantly (p < 0.05) fewer T. colubriformis at slaughter and significantly (p < 0.001) fewer eggs hatched in the egg hatch assay (EHA) than for lambs infused with water. Overall, the differences attributable to GSE were small in magnitude, being an 11% drop in egg hatch, and an 18% drop in numbers of adult T. colubriformis after 14 days of continuous infusion. No other differences were recorded.Conclusion: The results indicate that the in vivo anthelmintic activity of these CT sources is, at best, modest and is unlikely to be of any practical value. Further, these data emphasise that in vitro activity is an unreliable indicator of in vivo efficacy for CT-containing forages and extracts.

Eleven strains of ruminal bacteria (Streptococcus bovis NCFB 2476 and B315, Butyrivibrio fibrisolvens strains WV1 and C211, Prevotella ruminicola 23, Prevotella-like strain C21a, Eubacterium spp. C12b and C124b, Clostridium proteoclasticum B316T, Ruminococcus albus 8, and Fibrobacter succinogenes S85) were used to determine the effect of condensed tannins (CTs) from Lotus corniculatus (LC) on the proteolysis of the large (LSU) and small (SSU) subunit of ribulose-1,5-bisphosphate carboxylase (Rubisco) protein extracted from white clover (Trifolium repens), and on bacterial growth in vitro. The effects of CTs were determined with and without polyethylene glycol (PEG; 1.7 mg PEG/mg CT), which binds and inactivates CTs. Proteolysis of the LSU and the SSU of Rubisco (with 1.5 mg CT/ml) was determined in vitro and measured using a sodium dodecylsulphate polyacrylamide electrophoresis (SDS-PAGE) procedure. Bacterial growth in a plant protein medium containing 0, 50, 100, 200, 400, and 600 μg CT/ml was also measured after 0, 2, 4, 8, 12 and 24 h of incubation. Proteolytic bacterial cultures without CTs or with CTs + PEG degraded LSU and SSU rapidly (6–8%/h), but proteolysis varied markedly between species. Cultures of P. ruminicola C21a degraded both the LSU (11.3%/h) and SSU (9.8%/h) when grown in the presence of 1.5 mg CT/ml. Bacterial strains S. bovis B315 (11.5%/h) and strain NCFB 2476 (10.6%/h), Eubacterium sp. C12b (5.1%/h) and C124b (5.5%/h) appeared to degrade SSU more effectively than the LSU (2.6, 2.3, 3.8, and 2.6%/h, respectively) in the presence of 1.5 mg CT/ml. F. succinogenes S85, R. albus 8, P. ruminicola 23, C. proteoclasticum B316T, B. fibrisolvens WV1 and C211a had low (0.3%/h) to moderate (3–4%/h) rates of proteolysis when CT was included in the medium. In the absence of CT, all bacterial strains showed typical growth. Addition of 200, 400 and 600 μg CT/ml significantly (P < 0.05) reduced the growth rate and maximum optical density of most bacterial strains tested compared to the minus CT controls. Some strains (C. proteoclasticum B316T; P < 0.05 and R. albus 8; P = 0.09), however, showed transient increases in their growth rate at low (50–100 μg/ml), but not at high (>200 μg/ml) concentrations of CT. It was concluded that CTs from LC reduced the rate of proteolysis and inhibited the growth of proteolytic rumen micro-organisms.

The effects of a hot water infusion and an aqueous acetone extract of green tea (Camellia sinensis) on the motility of infective larvae of the sheep nematodes Teladorsagia circumcincta and Trichostrongylus colubriformis were investigated under in vitro conditions. The infusion and extract dose-dependently inactivated the infective larvae as assessed by the larval migration inhibition (LMI) assay. To determine the components responsible for the inhibitory activity, the hot water infusion and aqueous acetone extract of green tea were fractionated on Sephadex LH-20 and the green tea extract fractions (GTE-I–VIII) characterised by mass spectrometry. The larvae were exposed to increasing concentrations of these GTE fractions. Fractions containing epigallocatechin gallate (EGCG) and proanthocyanidin oligomers were most effective. GTE fractions were more effective against T. circumcincta than T. colubriformis larvae as assessed by the LMI assay.

The proanthocyanidin polymer fractions of the leaves of the forage legume Dorycnium rectum were analysed by acid catalysis with benzyl mercaptan, NMR and ES–MS. The results showed that D. rectum differs from other temperate proanthocyanidin-containing forage legumes in that the range of polymers extends up to very high degrees of polymerisation. Three fractions were characterised as low, medium, and high molecular weight proanthocyanidin fractions with mean degree of polymerisations of 10.3, 41 and 127, respectively. Epigallocatechin was the most abundant extension unit and the terminating flavan-3-ols comprised largely catechin and gallocatechin units in equal proportions. Formation of thiolyated dimer products showed the interflavan-linkages of the lower molecular weight proanthocyanidins to be predominantly C4→C8 with a small amount of C4→C6. ES–MS spectra distinguished lower from higher polymeric proanthocyanidins from M2− to M82−. The antibacterial activity of proanthocyanidin fractions against pure cultures of microbes selected from the ruminal population to represent fibre degrading, proteolytic and hyper ammonia producing bacteria in broth culture was evaluated. The activity of proanthocyanidin fractions against Clostridium aminophilum, Butyrivibrio fibrisolvens and Clostridium proteoclasticum was significantly dependent on their structure but not so against Ruminococcus albus and Peptostreptococcus anaerobius. The latter observation was unique in that they were sensitive to all proanthocyanidin fractions evaluated, even at the lowest concentration (100 μg/ml). The results suggest the effects of the extractable proanthocyanidins on rumen microbes should be considered when evaluating an alternative proanthocyanidin-containing forage source for ruminants, such as D. rectum.

The effects of flavan-3-ols (the monomer units of condensed tannins (CT)) and their galloyl derivatives on the viability of eggs, the development of first stage (L1) larvae, and the viability of the infective larvae of Trichostrongylus colubriformis were investigated under in vitro conditions. Each of the flavan-3-ol gallates showed some inhibition of egg hatching at 100 μg/ml, and 100% inhibition at 1000 μg/ml, with epigallocatechin gallate being the most effective in the egg hatch (EH) assay. In contrast, none of the flavan-3-ols were able to completely inhibit egg hatching. The flavan-3-ols and galloyl derivatives dose-dependently inhibited the development of infective larvae as assessed by the larval development (LD) assay. A larval migration inhibition (LMI) assay was used to assess the effect of flavan-3-ols and their galloyl derivatives on the motility of the infective third-stage (L3) larvae of T. colubriformis. In general, the flavan-3-ol gallates were more effective than the flavan-3-ols at immobilising the infective larvae as evidenced by their ability to inhibit more (P<0.05–0.01) larvae from passing through the LMI sieves. At 500 μg/ml, epigallocatechin gallate inhibited significantly more (P<0.1) larvae from passing through the sieves than did catechin gallate, epicatechin gallate, or gallocatechin gallate. Comparisons were made between the flavan-3-ols and their galloyl derivatives with the in vitro effects of CT extracts from several forage legumes, which have exhibited effects on parasites in vivo. The forage legumes tested at 200–500 μg/ml reduced the proportion of eggs that hatch, with comparable results to those obtained using the flavan-3-ols. The activities may be influenced by the prodelphinidin: procyanidin (PD:PC) ratios: CT extracts from Lotus pendunculatus and sainfoin have PD:PC ratios of 70:30 and 77:23, respectively, whereas the less active CT extract from Lotus corniculatus has a PD:PC ratio of 27:73. The active CT extracts from forage legumes have epigallocatechin as the dominant flavan-3-ol extender unit, and epigallocatechin is the most active flavan-3-ol in both the EH and LD assays.

The objective of this study was to determine the effects of condensed tannins (CT) and an extract containing crude sesquiterpene lactones (CSL) from chicory (Cichorium intybus) on the motility of the first-(L1) and third-stage (L3) larvae of deer lungworm Dictyocaulus viviparus and the L3 larvae of gastrointestinal nematodes in vitro, using the larval migration inhibition (LMI) assay. The CT and CSL had a profound effect on the motility of the larvae displayed by their ability to inhibit larval passage through nylon mesh sieves. Incubation of lungworm L1 larvae in rumen fluid (collected from deer fed pasture) containing 100, 400 and 1000 μg CT/ml, inhibited 12, 28 and 41% of the larvae from passing through the sieves, respectively, while the incubation of L3 larvae with rumen fluid (pH 6.6) containing the same concentrations inhibited 26, 37 and 67% of L3 larvae from passing through the sieves, respectively. Gastrointestinal larvae seem more susceptible to CT than lungworm larvae especially at higher concentrations. CT inhibited 27, 56 and 73% of gastrointestinal larvae from passing through the sieves when used at a concentration of 100, 400 and 1000 μg/ml, respectively. CT were more effective (P<0.001) at reducing the motility of lungworm L1 and L3 larvae when added to the rumen fluid than when added to the abomasal fluid (pH 3.0). Addition of 2 μg polyethylene glycol/μg CT eliminated the inhibitory effect of CT against L1 and L3 larvae especially during incubation in rumen fluid, confirming the effect as due to CT. The CSL extract also showed similar inhibitory activity against L1 and L3 lungworm and L3 gastrointestinal larvae in both fluids, indicating that this extract was not affected by the pH of the fluid, and was more effective against L3 than L1 lungworm larvae. Condensed tannins appeared to be more effective than CSL at inactivating L1 and L3 lungworm and L3 gastrointestinal larvae in rumen fluid, but CSL were particularly effective against L3 lungworm larvae in abomasal fluid. Activity of these secondary compounds explains the reduced parasite problem of young deer grazing chicory.