H. Muklada

Anthelmintic activity of Pistacia lentiscus foliage in two Middle Eastern breeds of goats differing in their propensity to consume tannin-rich browse.

The Damascus and Mamber breeds of goats thrive in Middle Eastern Mediterranean regions where the tannin-rich (20% of polyethylene glycol-binding tannins) brush species Pistacia lentiscus L. (lentisk) is ubiquitous. In light of the increasing recognition of the anthelmintic activity of plant tannins, we examined the effect of offering lentisk foliage for 24 days on fecal egg excretion in 5.5-month-old Damascus and Mamber kid goats (n=28) following infection with 10,000 L3 larvae of mixed gastro-intestinal nematodes (GIN). Lentisk foliage was consumed with or without a daily supplement of 20 g polyethylene glycol (PEG; MW 4000). Lentisk tannins showed a strong protein-depletive effect that was totally reversed by the addition of PEG. At the peak of infection, kids of the two breeds lost weight unless they were fed with lentisk without PEG. Fecal egg counts (FEC) were lowest - and did not differ from 0 - in kids fed lentisk without PEG, highest in the controls fed hay as roughage, and intermediate in kids fed lentisk and PEG (241, 1293, and 705 eggs per gram, respectively, SEM 180; P<0.001); therefore, the anthelmintic activity of lentisk was only partly attributable to tannins. The suppressive effect of lentisk on FEC ceased when feeding was discontinued, suggesting that female parasites were not killed but their fertility was reversibly impaired. Damascus kids showed lower FEC than their Mamber counterparts, inferring that the effect of foraging on tannin-rich species is only additive to genetic differences between goat breeds in their sensitivity to GIN infection. On the basis of our results we would expect yearlong lentisk grazing to result in no or very low GIN infection, and Damascus goats to have some advantage over Mamber goats where chemical control of GIN is unfeasible. There appears to be a trade-off between the benefits of lentisk tannin as drug and its side-effects (protein depletion) when given at high level; how goats balance this trade-off requires further elucidation.

A fecal near-infrared reflectance spectroscopy-aided methodology to determine goat dietary composition in a Mediterranean shrubland

An ecologically sound approach to the problem of brush encroachment onto Israeli rangeland might be their utilization by goats, but better knowledge of the feeding selectivity and ability of goats to thrive in encroached areas is required to devise viable production systems. Direct observation of bites could provide precise and accurate estimates of diet selection, but construction of a sufficiently large database would require too much time. The present study describes the first attempt to construct fecal near-infrared reflectance spectroscopy (NIRS) calibrations of the botanical and nutritional composition of the diet, and of the total intake of free-ranging goats, based on reference values determined with bite-count procedures. Calibration of fecal NIRS was based on 43 observations encompassing 3 goat breeds and 4 periods (spring, summer, and fall of 2004, and spring of 2005). Each observation comprised 242 min of continuous recording of the species and bite-type category selected by a single animal, on each of 2 consecutive days. The mass and chemical quality of each species and bite-type category-a total of more than 200,000 bites-were determined by using the simulated bite technique. Associated feces were scanned in the 1,100- to 2,500-nm range with a reflectance monochromator. Fecal NIRS calibrations had reasonable precision for dietary percentages of the 3 main botanical components: herbaceous vegetation (as one category; R(2) = 0.85), Phillyrea latifolia (R(2) = 0.89), and tannin-rich Pistacia lentiscus (R(2) = 0.77), with SE of cross-validation (SECV) of 7.8, 6.3, and 5.6% of DM, respectively. The R(2) values for dietary percentages of CP, NDF, IVDMD, and polyethylene glycol-binding tannins were 0.93, 0.88, 0.91, and 0.74, respectively, with SECV values of 0.9, 2.1, 4.3, and 0.9% of DM, respectively. The R(2) values for intakes of herbaceous vegetation, P. latifolia, and P. lentiscus were 0.80, 0.75, and 0.65, with SECV values of 71, 64, and 46 g of DM/d, respectively. The R(2) values for the daily nutrient intakes were below 0.60. Fecal NIRS data can be used to expand the databases of botanical and nutritional dietary composition when observed and resident animals graze simultaneously, but intakes should be calculated from fecal NIRS-predicted dietary DM composition and an independent evaluation of DMI.

Polyphenols from Pistacia lentiscus and Phillyrea latifolia impair the exsheathment of gastro-intestinal nematode larvae

The infection of grazing ruminants with gastro-intestinal nematodes (GINs) is a severe problem in the Middle East. However, goats that graze the south-western slopes of the Carmel Heights in Israel have very low faecal egg counts, despite high grazing density. We hypothesized that polyphenols from Pistacia lentiscus L. and/or Phillyrea latifolia L. - both prevalent woody species of the region that are consumed by goats - have anthelmintic bioactivity. We tested this hypothesis by using the larval exsheathment inhibition assay (LEIA). Extracts were prepared from leaves of either plant species using 70% ethanol (E70), 100% ethanol (E100), or boiling water (W). Larvae were incubated in a phosphate-buffered saline solution with or without plant extract (1200μg/ml) and then exposed to an exsheathment solution expected to elicit 100% exsheathment after one hour. All extraction methods of P. lentiscus were highly effective at inhibiting larval exsheathment, but higher potency was found for the E70 than for E100 extraction method, while W was intermediate. Only the E70 extract of P. latifolia was highly effective relative to the control. The E70 extract of P. lentiscus had more than 7 times the potency of the E70 extract of P. latifolia. Irrespective of solvent and tannin-equivalent used, P. lentiscus contained more than double the quantity of total polyphenols than P. latifolia. The polyphenols of P. lentiscus consisted mainly of galloyl derivatives (63.6%), flavonol glucosides (28.6%), and catechin (7.8%). In P. latifolia, oleuropein and its derivative tyrosol accounted for 49.3 and 23.1% of phenolics, respectively, the remainder being flavones (luteolin and quercetin) and their glucoside derivatives. Results of the LEIA test suggest that extracts of tannin-rich plants interfere with the very early stage of host invasion and that high concentration of galloylated derivatives may explain anthelmintic activity.

Self-medication with tannin-rich browse in goats infected with gastro-intestinal nematodes.

Primates self-medicate to alleviate symptoms caused by gastro-intestinal nematodes (GIN) by consuming plants that contain secondary compounds. Would goats display the same dietary acumen? Circumstantial evidence suggests they could: goats in Mediterranean rangelands containing a shrub - Pistacia lentiscus - with known anthelmintic properties consume significant amounts of the shrub, particularly in the fall when the probability of being infected with GIN is greatest, even though its tannins impair protein metabolism and deter herbivory. In order to test rigorously the self-medication hypothesis in goats, we conducted a controlled study using 21 GIN-infected and 23 non-infected goats exposed to browse foliage from P. lentiscus, another browse species - Phillyrea latifolia, or hay during the build-up of infection. GIN-infected goats showed clear symptoms of infection, which was alleviated by P. lentiscus foliage but ingesting P. lentiscus had a detrimental effect on protein metabolism in the absence of disease. When given a choice between P. lentiscus and hay, infected goats of the Mamber breed showed higher preference for P. lentiscus than non-infected counterparts, in particular if they had been exposed to Phillyrea latifolia before. This was not found in Damascus goats. Damascus goats, which exhibit higher propensity to consume P. lentiscus may use it as a drug prophylactically, whereas Mamber goats, which are more reluctant to ingest it, select P. lentiscus foliage therapeutically. These results hint at subtle trade-offs between the roles of P. lentiscus as a food, a toxin and a medicine. This is the first evidence of self-medication in goats under controlled conditions. Endorsing the concept of self-medication could greatly modify the current paradigm of veterinary parasitology whereby man decides when and how to treat GIN-infected animals, and result in transferring this decision to the animals themselves.

Consumption of Pistacia lentiscus foliage alleviates coccidiosis in young goats

Coccidiosis near weaning is a major cause of diarrhea, ill-thrift, and impaired performance in small ruminants. A recent survey showed that in villages of the Samaria Hills, Israel, shepherds treat young, weaned goat kids afflicted with diarrhea by cutting and feeding them the foliage of Pistacia lentiscus L. (lentisk) or by tethering them close to lentisk bushes which they browse. The aim of the present study was to assess whether lentisk leaves do indeed have anti-coccidial value, and, if positive, to ascertain the role of tannins in this effect. We monitored for 24 (Experiment 1) and 30 (Experiment 2) days the effect of lentisk feeding on the development of naturally occurring coccidiosis in weaned kids artificially infected with parasitic nematodes. In Experiment 1, kids were infected with nematodes and fed lentisk foliage (PIS) or cereal hay (HAY). Coccidiosis developed at the early stage of the nematode infection, when dietary treatments were initiated. Kids in the PIS group had a lower (P<0.02) concentration of oocysts per gram feces (opg). In Experiment 2, aimed at verifying if tannins are the active component in lentisk foliage, coccidiosis occurred at the peak of the nematode infection, before experimental diets were initiated. Dietary treatments were: cereal hay (HAY), or lentisk foliage consumed without (PIS) or with (PISPEG) a 20-g daily supplement of polyethylene glycol (PEG; MW 4000), a molecule that impairs tannin-bonding with proteins. Goats fed the PIS diet had lower fecal opg counts than counterparts of the HAY (P<0.001) and PISPEG (P<0.002) treatments. Fecal opg counts for the HAY and PISPEG treatments did not differ, suggesting that the anti-coccidial moiety in lentisk was indeed tannins. Our results strongly suggest that: (i) in agreement with the ethno-veterinary anecdotal evidence, exposure of young, weaned goat kids to lentisk foliage alleviates coccidiosis; and (ii) this positive effect is associated with tannins. As coccidiosis is a major affliction of kids, providing them with tannin-rich browse near weaning could be an environmentally friendly way of improving their welfare and health status, in particular under bio-organic farm management.

Effects of tannin-rich host plants on the infection and establishment of the entomopathogenic nematode Heterorhabditis bacteriophora

Parasitized animals can self-medicate. As ingested plant phenolics, mainly tannins, reduce strongyle nematode infections in mammalian herbivores. We investigated the effect of plant extracts known to be anthelmintic in vertebrate herbivores on the recovery of the parasitic entomopathogenic nematode Heterorhabditis bacteriophora infecting African cotton leafworm (Spodoptera littoralis). Nematode infective juveniles (IJs) were exposed to 0, 300, 900, 1200, 2400 ppm of Pistacia lentiscus L. (lentisk), Inula viscosa L. (strong-smelling inula), Quercus calliprinos Decne. (common oak) and Ceratonia siliqua L. (carob) extracts on growth medium (in vitro assay). In control treatments, 50-80% of IJs resumed development to J4, young and developed adult hermaphrodites, whereas all extracts, except for C. siliqua at 300 ppm, impaired IJ exsheathment and development. The highest concentration of I. viscosa extract (2400 ppm) had the strongest effect, killing 95% of exposed nematodes. Surviving nematodes did not recover, remaining at the IJ stage. Over the whole cycle, I. viscosa extract inhibited recovery to 25% or less, and did not allow full development to adulthood, whereas 65% of IJs in the control treatment recovered and resumed development, 12% reaching complete maturation within 72 h of incubation. When herbivorous S. littoralis larvae were fed with different plant extracts in vivo, I. viscosa had the strongest effect at concentrations above 300 ppm, with 90% of insect-invading IJs not developing to parasitic stages, whereas in the control treatment, 85% of IJs resumed development. Exposure to C. siliqua extract also inhibited exsheathment and development of 75% of the IJs. Half of those that resumed development reached full maturation. P. lentiscus and Q. calliprinos extracts also inhibited development of 50% IJs. Our results suggest that H. bacteriophora can be used to study herbal medication against parasites in animals.

Traditional Uses of Pistacia lentiscus in Veterinary and Human Medicine

Pistacia lentiscus L. is an evergreen shrub or tree of the Anacardiaceae family that is ubiquitous in Mediterranean areas under 1,100 m above sea level. The essential oil obtained from the gum/resin is commonly called mastic oil, whereas the oil obtained from the leaves is termed lentisk oil. Mastic, foliage, and fruit essential oils have served in traditional human medicine for millennia. In human medicine, aqueous extracts of leaves and young twigs are prepared as infusions or decoctions. Leaves and young twigs are used “as is” in veterinary medicine. Extracts exhibit a high concentration of phenolics and terpenes of varying composition. In addition to the traditional use of mastic resin in human medicine against stomach ulcers, evidences for anti-bacterial, antifungal, antioxidant, hepato-protective, and anti-carcinogenic properties of products sourcing from P. lentiscus, some of them controversial, are accumulating. The anthelmintic and anticoccidial properties of P. lentiscus foliage have been recently demonstrated in small ruminants. Metabolomics, encompassing new analytical procedures will probably help in elucidating the rationale of traditional medicine in using P. lentiscus for therapies or prevention. It can be expected that new cultivars will be cultivated on the basis of bio-activity.

Goat farming and landscape management: from controlled research to controlled grazing

In May, 2002 fourteen Damascus goats were bought and held at the Ramat-Hanadiv Nature Park on Mt. Carmel, in central Israel. The main purpose of purchasing the goats was to collect scientific information regarding grazing behaviour of different goat breeds and seasons and apply it in the management of the nature park. The research aimed at bridging the agricultural and ecological aspects of grazing in Mediterranean shrubland and reconciling the needs of both farmers and landscape managers. Fecal NIRS calibrations were developed using the MPLS routine of the Win- ISI II software in order to determine dietary quality and botanical composition of free-grazing goats’ diets. Reference values for calibration were obtained by a NIRS-oriented observation method that combined focal observation, digital recording and computerized ‘reconstruction’ of the diet. Further on, the equations were used for determining dietary composition of three goat breeds (Damascus, Boer and Mamber) in different seasons. These data were implemented in the context of a yearly grazing program at the park. Due to the relatively poor results of the Boer goats, they were excluded and the herd has expanded (to 150 head) with Mamber and Damascus goats. The herd forages daily at specific locations in the park with specific management goals, such as suppression of P. lentiscus (approx. 20% tannins) or consumption of forest understory vegetation. Most scientific results are implemented in the park and herd management. The herd serves as a semi-commercial herd, since milk and cheese are produced, as well as for agro-tourism activities.

Ethanolic extracts of Inula viscosa, Salix alba and Quercus calliprinos, negatively affect the development of the entomopathogenic nematode, Heterorhabditis bacteriophora – A model to compare gastro-intestinal nematodes developmental effect

Heterorhabditis bacteriophora can represent a model system for herbal medication against gastro-intestinal strongylid parasites in determining the recovery and development due to their unique parasitic infectious cycle. The fact that plant extracts impair nematode development is known but their differential impact on stages of the life cycle of H. bacteriophora has never been investigated. We examined the developmental stages resumed from eggs, young juveniles (J1-3), infective juveniles (IJs), young and adult hermaphrodites of H. bacteriophora upon exposure to crude ethanolic extracts of Inula viscosa, Salix alba, and Quercus calliprinos at concentrations of 600, 1200, and 2400ppm. Our results showed that plant extracts were highly toxic to the survival of the eggs and young juveniles J1 to J3 at all concentrations. The plant extracts inhibited their development and were associated with low reproduction parameters (i.e. fecundity and viability of eggs). The IJs, J4, young and developed hermaphrodites displayed concentration-dependent negative effect on development with less egg count, poor vulval muscle development, loss of egg laying capacity and progeny development by matricidal hatching. Plant extract of I. viscosa at low (600ppm) concentration did not impair vulval development. These results suggest that these plant extracts show potential for the control of parasitic rhabditids.