Nematode Load Research Articles

Effect of calcium soaps from garlic (Allium sativum) and willow (Salix babylonica) extracts on nematode loads, nutrient intake and digestibility, nitrogen balance and rumen fermentation kinetics in dairy goats.

The objective of this study was to determine the effect of dietary calcium soaps from garlic (Allium sativum) and willow (Salix babylonica) extracts on nematode loads, nutrient intake and digestibility, nitrogen balance and rumen fermentation kinetics in dairy goats. Nine adult non-lactating Saanen goats were grouped into a complete randomized block design with 3 treatments (n = 3) over a period of 28 d. Animals were fed a diet based on alfalfa hay and a concentrate that was supplemented (65 g/kg DM) with calcium soaps of safflower (control), garlic or willow. Intake of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) were not affected by dietary calcium soaps. However, the highest digestibility of DM and OM were observed in willow supplemented goats. In vitro gas kinetics and fermentation profile were not affected by diets. Results from fecal egg count indicated a reduction in total count, Haemonchus spp. and Trychostrongylus spp. for both garlic and willow compared to control. Our results suggest that calcium soaps of garlic or willow extracts can be used to reduce gastrointestinal parasites in goats without compromising productive traits or rumen function.

Comparison of transmission of Bursaphelenchus mucronatus via two different pathways from Monochamus saltuarius to host trees

Summary Bursaphelenchus xylophilus, the causative agent of pine wilt disease, and B. mucronatus are transmitted by Monochamus adults to host trees. Feeding and oviposition wounds made by vectors are the primary transmission pathways to trees. Monochamus saltuarius female adults carrying B. mucronatus were reared singly and allowed to mate with nematode-free males at 5-day intervals, to determine the ratio of nematodes transmitted via the two different pathways. The survival time, lifetime fecundity and other reproductive traits decreased with increasing initial nematode load (number of nematodes carried by a newly-emerged adult). Model selection indicated that numbers of B. mucronatus departing from M. saltuarius and of those transmitted to pine via oviposition and feeding wounds were closely related to the initial nematode load, which was affected by survival time and number of oviposition wounds constructed. Most temporal patterns of nematode departure and transmission via oviposition or feeding wounds from individual vectors had a peak in the medium and heavy initial nematode loads. The nematode departure curve was significantly similar in shape to each of the nematode transmission curves via oviposition and feeding wounds, which were not significantly similar to each other, for individual vectors. After M. saltuarius females began to construct the oviposition wounds, it was estimated that B. mucronatus was transmitted via the oviposition wounds at a probability of 0.767. If B. xylophilus is transmitted in the same way as B. mucronatus, the incidence of pine wilt disease by mature vectors would be much lower than in the case of no oviposition-related transmission.

Parasite load effects on sex ratio, size, survival and mating fitness of Heleidomermis magnapapula in Culicoides sonorensis.

Heleidomermis magnapapula parasitizes the blood-feeding midge Culicoides sonorensis. Most (84%) single mermithid infective second stage juveniles (J2) developed into adult females, while parasitism by multiple J2 yielded 97% male adults. Nematodes emerged from the midge larval host as adults and mated immediately; females were ovoviviparous. Host larvae were exposed to nematode J2 and examined intact microscopically to score initial parasite load. Midge hosts were reared individually. Premature midge death, nematode survival within the host, and emerging adult nematode sex ratio and size as a function of load and host size were all tracked. Higher nematode loads produced smaller adult nematode males. The higher loads also increased and accelerated premature host death. Emergence of > 7-9 adult nematode males was rare, but up to 19 tiny males emerged from a single host. Larger midges supported higher parasite loads and a larger total volume of emerged nematode biomass. Virgin adult nematode males then were paired with females of variable, known sizes (volume) and held to determine size effects on fertility (egg hatch), and male survival (longevity). Tested adult males ranged in size from 0.0025 - 0.0334 mm3 and females from 0.0121 - 0.1110 mm3. Logistic regression indicated female nematode fertility was positively influenced by male nematode size, while nematode load and female nematode size had no significant effect. While fertility was reduced statistically in smaller males, even some of the smallest male and female individuals could be fertile. Findings are related to field studies in this system.

Influence of Thermal Regimes on the Relationship between Parasitic Load and Body Condition in European Sardine along the Catalan Coast

The small pelagic European sardine presents high commercial and ecological values. Due to its cold-temperate water affinity, stocks are affected by global warming. Water temperature rise may change primary productivity patterns, negatively affecting fish condition and increasing parasite incidence. In this context, sardine health status was evaluated through the annual cycle on the Catalan Coast using thermal regimes comparison. Morphogravimetric parameters, sex and gonadal stages were assessed; infection by nematodes was characterised, and body condition was estimated by the Le Cren Factor and lipid content measured using a fish fat meter. Significant statistical differences were observed in spawning dynamics, body condition, and parasite infection between thermal regimes. Sardines from the colder north area had better condition and an earlier spawning, with lower parasite incidence (in terms of total prevalence, mean intensity and abundance) than those from the southern coast. Hysterothylacium spp. was the most abundant nematode, while Anisakis spp. prevalence was null in the two locations. Seasonal differences in nematode load were observed along the Catalan Coast, with lower prevalence during the summer and higher in winter-spring. Although previous studies have underestimated parasite influence on sardine health status, parasite abundance and sardine condition were negatively correlated. Seawater temperature and primary productivity are the proposed factors promoting differentiation in nematode infection and fish condition throughout the annual cycle and between locations.

Morph‐dependent nematode infection and its association with host movement in the land snail Cepaea nemoralis (Mollusca, Gastropoda)

AbstractHost behaviour can be influenced by parasitic risk and infection through a variety of direct and indirect mechanisms. We can expect individuals expressing different phenotypes to also differ in the ways their behaviour is altered by parasites. We used the land snail Cepaea nemoralis, a species with various shell colour morphs differing in behaviour and physiology, as a model to study the link between parasite response and individual behaviour variation. We analysed metazoan parasite abundance and its relation to behaviour (movement and food intake) in snails from three shell morphs (from light unbanded to darker five‐banded) and from two neighbouring populations from contrasting environments. Snails were parasitized by mites, trematodes, and nematodes, from rarest to most frequent. We confirm that terrestrial gastropods can defend against infection by trapping parasitic nematodes in their shell. We show that nematodes encapsulated in shells can uncover past infections even when a snail population is currently nematode‐free, possibly due to parasite seasonality. We present new observations suggesting that not only nematodes but also mites might be encapsulated in shells. Infection levels varied between morphs, with darker snails harbouring fewer nematodes. Behaviour (movement and food intake) was linked to the nematode, but not trematode infection. Individuals with higher nematode load ate less, irrespective of morph and population. The most‐infected morph (unbanded snails) showed reduced activity in the nematode‐infected population compared to the one that was nematode‐free at sampling time. As a result, parasites may cancel previously described behavioural differences between morphs. We discuss the possible mechanisms explaining morph‐dependent responses to parasites, and how parasite risk may be an unseen force shaping C. nemoralis morph variation in space and time. We conclude with the possible ecological consequences of the link, mediated by shell colour, and between thermal and immune responses.

Transfer of four isolates of Bursaphelenchus doui into Monochamus alternatus and potential vector switching of the nematode

Summary To reinforce vector-switching potential of Bursaphelenchus doui in its ecological and evolutionary contexts, we tested our previous hypothesis that “B. doui (or its ancestor) was transferred by Acalolepta fraudatrix, Acalolepta sejuncta, and/or Monochamus subfasciatus (or their ancestral species) from broad-leaved trees to conifers, switched vectors from these cerambycid beetles to Monochamus beetles in conifers, and then evolved into the common ancestor of Bursaphelenchus mucronatus and Bursaphelenchus xylophilus”. The affinity of four B. doui isolates and one B. xylophilus isolate for Monochamus alternatus was tested using our simple nematode-loading method to the beetle, and the affinity was assessed based on the nematode loads on the beetles. Phoretic stages of two B. doui isolates obtained from Monochamus saltuarius and Pinus densiflora showed loading levels similar to that of B. xylophilus, which were significantly higher than those of the other two B. doui isolates obtained from A. fraudatrix and M. subfasciatus. This result indicates that the first two isolates of B. doui derived from a conifer-using beetle and a coniferous tree adapt to M. alternatus better than the last two isolates associated with beetles using broad-leaved trees. The data reinforce that vector switching of B. doui could have occurred during the evolutionary history of the B. xylophilus group.

Investigating associations between nematode infection and three measures of sociality in Asian elephants

Frequent social interactions, proximity to conspecifics, and group density are main drivers of infections and parasite transmissions. However, recent theoretical and empirical studies suggest that the health benefits of sociality and group living can outweigh the costs of infection and help social individuals fight infections or increase their infection-related tolerance level. Here, we combine the advantage of studying artificially created social work groups with different demographic compositions with free-range feeding and social behaviours in semi-captive Asian elephants (Elephas maximus), employed in timber logging in Myanmar. We examine the link between gastro-intestinal nematode load (strongyles and Strongyloides spp.), estimated by faecal egg counts, and three different aspects of an elephant’s social world: individual solitary behaviour, work group size, and work group sex ratio. Controlling for sex, age, origin, time since last deworming treatment, year, human sampler bias, and individual identity, we found that infection by nematodes ranged from 0 to 2720 eggs/g between and within 26 male and 45 female elephants over the 4-year study period. However, such variation was not linked to any investigated measures of sociality in either males or females. Our findings highlight the need for finer-scale studies, establishing how sociality is limited by, mitigates, or protects against infection in different ecological contexts, to fully understand the mechanisms underlying these pathways.Significance statementBeing social involves not only benefits, such as improved health, but also costs, including increased risk of parasitism and infectious disease. We studied the relationship between and three different sociality measures—solitary behaviour, group size, and the proportion of females to males within a group—and infection by gut nematodes (roundworms), using a unique study system of semi-captive working Asian elephants. Our system allows for observing how infection is linked to sociality measures across different social frameworks. We found that none of our social measures was associated with nematode infection in the studied elephants. Our results therefore suggest that here infection is not a large cost to group living, that it can be alleviated by the benefits of increased sociality, or that there are weak infection–sociality associations present which could not be captured and thus require finer-scale measures than those studied here. Overall, more studies are needed from a diverse range of systems that investigate specific aspects of social infection dynamics.

Do water shortages increase gastrointestinal nematode loads in Nguni does?

The objective of the study was to assess the effects of water deprivation on the burden of gastrointestinal nematodes in Nguni does. A survey was piloted on goat keepers in households where water was scarce (n = 143) and where it was available throughout the year (n = 142). In a controlled experiment, feed intake (ADFI), body condition score (BCS), FAMACHA score, packed cell volume (PCV) and faecal egg counts (FEC) were determined in does deprived of water for 24 and 48h. There was a significant association between the frequency with which goats drink water and the distance from the water source. From the experiment, an increase in the water deprivation period decreased ADFI, BCS and PCV, and increased FAMACHA scores and faecal egg counts in Nguni goats. The BCS of goats deprived of water for 48h was 12% lower than the control (p < 0.05). Reduction in water supply increased gastrointestinal burdens in does, which may compromise their productivity and production efficiency. Depriving goats of water for 24h had no significant effect on gastrointestinal nematode (GIN) loads. The deprivation period of 48h increased the GIN burden in does.

Relationship between the initial number of carried Bursaphelenchus xylophilus and its transmission by Monochamus carolinensis with reference to virulence

Summary The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the causative agent of pine wilt disease and is transmitted by cerambycid adults of the genus Monochamus. It is believed to have been introduced into Japan from North America in the 1900s and since then it has been devastating the native pine forests. By contrast, the epidemics of the disease have never occurred in pine forests native to North America in the original habitats, indicating no expression of virulence. To determine the evolutionary change in the transmission traits of PWN, the temporal pattern of PWN transmission to fresh branch sections of Pinus sylvestris was studied using 38 Monochamus carolinensis adults in Illinois, USA, and compared with previous studies on the PWN-M. alternatus and B. mucronatus-M. saltuarius systems in Japan. A great difference was observed in the initial nematode load among vectors irrespective of the three systems. The maximal numbers of PWN transmitted (5 days)−1 by individual vectors were greater and the efficiencies of nematode transmission and invasion were higher for the Japanese PWN-M. alternatus system than for the North American PWN-M. carolinensis system in two heavy classes of initial load of over 1000 nematodes. The proportion of PWN transmitted to healthy pine trees by reproductively immature female vectors was small (2.5-11.5%) in the three nematode-vector systems in most cases. The evolutionary changes in the transmission traits and the control of the range expansion of the PWN were discussed in relation to the expression of virulence.

A generalist nematode destabilises plant competition: no evidence for direct effects, but strong evidence for indirect effects on rhizobium abundance.

Difficulties quantifying pathogen load and mutualist abundance limit our ability to connect disease dynamics to host community ecology. For example, specific predictions about how differential pathogen load is hypothesised to drive host competitive outcomes are rarely tested. Additionally, although infection is known to affect mutualists, we rarely measure the magnitude of pathogen effects on mutualist abundance across host competitive contexts. We tested for both mechanisms in a plant-rhizobia-nematode system. We paired the legume Medicago lupulina with intraspecific and interspecific plant competitors, with and without a generalist nematode parasite Meloidogyne sp. Relative change in plant biomass was used to determine how nematode inoculation affected plant competitive outcomes. We counted nematode galls to test for direct effects of parasitism on plant competition and rhizobia nodules to test for indirect effects of nematode presence on rhizobium abundance. Parasites were destabilising despite similar nematode load across competition treatments. During interspecific compared with intraspecific competition, nematode inoculation decreased nodulation on M. lupulina, increased nodulation on Trifolium repens and had no effect on nodulation on Chamaecrista fasciculata. We found no support for hypothesised direct effects of nematode load on competitive outcomes and strong but idiosyncratic indirect effects of nematode inoculation on rhizobium abundance.

Differential effects of nematode infection on pollinating and non‐pollinating fig wasps: Can shared antagonism provide net benefits to a mutualism?

Species pairs that form mutualistic associations are also components of broader organismal community networks. These interaction networks have shaped the evolution of individual mutualisms through interspecific interactions ranging from secondarily mutualistic to intensely antagonistic. Our understanding of this complex context remains limited because characterizing the impacts of species interacting with focal mutualists is often difficult. How is the fitness of mutualists impacted by the co-occurring interactive network of community associates? We investigated this context using a model interaction network comprised of a fig and fig wasp mutualist, eight non-pollinating fig wasp (NPFW) antagonists/commensals and a nematode previously believed to be associated only with the pollinator wasp mutualist. Through repeated sampling and field observations, we characterized the ecological roles of these mutualist-associated organisms to identify key antagonists. We then investigated how potential nematode infection of NPFWs could impact wasp survival across key life stages and, in turn, inferred how this influences the fitness of the fig-pollinator mutualists. Unexpectedly, we found all Ficus petiolaris-associated NPFWs to be the targets for nematode infection, with infection levels sometimes exceeding that of pollinators. Experimental data collected for the most abundant NPFW species suggest that nematode infection significantly reduces their longevity. Further, comparisons of nematode loads for emerging and successfully arriving NPFWs suggest that infection severely limits their dispersal ability. Through these observations, we conclude that this infection could impact NPFWs more severely than either mutualistic partner, suggesting a novel role of density-dependent facultative mutualism between figs, pollinator wasps and the nematode. This antagonist-mediated suppression of other network antagonists may present an ecologically common mechanism through which antagonists can present net benefits for mutualists' fitness.

Influences of living and dead nematodes of Aphelenchoides besseyi (Aphelenchida: Aphelenchoididae) and artificial defoliation on rice seed ripening

Aphelenchoides besseyi Christie (Aphelenchida: Aphelenchoididae) is a seed-borne ectoparasite of rice Oryza sativa Linnaeus and the causative agent of white tip disease. To evaluate effects that the amount of substances translocated to seeds and the consumption by nematodes exert on seed size, 20 μL water containing 100 living or dead nematodes or no nematodes was inoculated individually into florets in bloom that appeared on culms with the amount of foliage modified: culms with no blades, half-cut blades, or intact blades of the three uppermost leaves. Inoculation of living A. besseyi nematodes into rice florets resulted in the highest proportion of light seeds (specific gravity < 1.0) whereas the removal of leaf blades had no effects on the occurrence of light seeds. Seed swelling, volume, weight, and volume density were the smallest for seeds derived from florets inoculated with living nematodes, indicating the effects of feeding by living nematodes. By contrast, those traits of seeds were not affected by the removal of leaf blades. Intriguingly, a positive correlation was found between nematode load per seed (total number of nematodes recovered) and seed weight when florets had been inoculated with living nematodes. Effects of nematodes on seed development was discussed.

Correlated evolution between herbivory and gastrointestinal tract in a prolific lizard adaptive radiation

Abstract Radiations of ectothermic vertebrates across cold climates depend on the coordinated evolution of multiple traits that compensate for the constraints imposed by limited and fluctuating resources, such as temperature, food and oxygen. One of nature’s most prolific such radiations, Liolaemus lizards, has diversified across the extreme cold climates of the Andes and Patagonia. Remarkably, the prevailing patterns of reptile herbivory are opposed by Liolaemus which, in contrast with lizards generally, have repeatedly evolved plant consumption across small-bodied species from cold climates. Herbivory is hypothesized to depend on the evolution of multiple traits that maximize absorption of nutrients from an intrinsically poor-quality diet, such as increases in gastrointestinal tract size and increases in the density of nematodes in the intestine that may assist with plant digestion. Here, a comparative phylogenetic approach across Liolaemus species is implemented to test these hypotheses, which have only been investigated nonphylogenetically. Results reveal that intestine length increases consistently with increasing herbivory, whereas stomach size or nematode load are not associated with plant consumption. Body size plays no role in herbivory either. Consequently, this evidence places emphasis on the enlargement of the intestine to facilitate the evolution of herbivory in cold climates.

Helminth communities in amphibians from Latvia, with an emphasis on their connection to host ecology

Helminth infracommunities were studied at 174 sites of Latvia in seven hosts from six amphibian taxa of different taxonomical, ontogenic and ecological groups. They were described using a standard set of parasitological parameters, compared by ecological indices and linear discriminant analysis. Their species associations were identified by Kendall's rank correlation, but relationships with host size and waterbody area were analysed by zero-inflated Poisson and zero-inflated negative binomial regressions. The richest communities (25 species) were found in post-metamorphic semi-aquatic Pelophylax spp. frogs, which were dominated by trematode species of both adult and larval stages. Both larval and terrestrial hosts yielded depauperate trematode communities with accession of aquatic and soil-transmitted nematode species, respectively. Nematode loads peaked in terrestrial Bufo bufo. Helminth infracommunities suggested some differences in host microhabitat or food object selection not detected by their ecology studies. Associations were present in 96% of helminth species (on average, 7.3 associations per species) and dominated positive ones. Species richness and abundances, in most cases, were positively correlated with host size, which could be explained by increasing parasite intake rates over host ontogeny (trematode adult stages) or parasite accumulation (larval Alaria alata). Two larval diplostomid species (Strigea strigis, Tylodelphys excavata) had a negative relationship with host size, which could be caused by parasite-induced host mortality. The adult trematode abundances were higher in larger waterbodies, most likely due to their ecosystem richness, while higher larval abundances in smaller waterbodies could be caused by elevated infection rates under high host densities.

Pathogen-associated selection on innate immunity genes (TLR4, TLR7) in a neotropical rodent in landscapes differing in anthropogenic disturbance

Toll-like receptors (TLRs) form part of the innate immune system and can recognize structurally conserved pathogen-associated molecular pattern (PAMP) molecules. Their functional importance in the resistance to pathogens has been documented in laboratory experimental settings and in humans. TLR diversity, however, has been rarely investigated in wildlife species. How the genetic diversity of TLRs is associated with various pathogens and how it is shaped by habitat disturbance are understudied. Therefore, we investigated the role of genetic diversity in the functionally important parts of TLR4 and TLR7 genes in resistance towards gastrointestinal nematodes and Hepacivirus infection. We chose a generalist study species, the rodent Proechimys semispinosus, because it is highly abundant in three Panamanian landscapes that differ in their degree of anthropogenic modification. We detected only two TLR7 haplotypes that differed by one synonymous single-nucleotide polymorphism (SNP) position. The TLR4 variability was higher, and we detected four TLR4 haplotypes that differed at one synonymous SNP and at three amino acid positions within the leucine-rich repeat region. Only TLR4 haplotypes had different frequencies in each landscape. Using generalized linear models, we found evidence that nematode loads and virus prevalence were influenced by both specific TLR4 haplotypes and landscape. Here, the variable “landscape” served as a surrogate for the important influential ecological factors distinguishing landscapes in our study, i.e. species diversity and host population density. Individuals carrying the common TLR4_Ht1 haplotype were less intensely infected by the most abundant strongyle nematode. Individuals carrying the rare TLR4_Ht3 haplotype were all Hepacivirus-positive, where those carrying the rare haplotype TLR4_Ht4 were less often infected by Hepacivirus than individuals with other haplotypes. Our study highlights the role of TLR diversity in pathogen resistance and the importance of considering immune genetic as well as ecological factors in order to understand the effects of anthropogenic changes on wildlife health.

Demographic and reproductive associations with nematode infection in a long-lived mammal

Infection by macroparasites, such as nematodes, varies within vertebrate host systems; elevated infection is commonly observed in juveniles and males, and, for females, with different reproductive states. However, while such patterns are widely recognized in short-lived model systems, how they apply to long-lived hosts is comparatively understudied. Here, we investigated how infection varies with host age, sex, and female reproduction in a semi-captive population of individually marked Asian elephants Elephas maximus. We carried out 1,977 faecal egg counts (FECs) across five years to estimate nematode loads for 324 hosts. Infection patterns followed an established age-infection curve, whereby calves (5 years) exhibited the highest FECs and adults (45 years) the lowest. However, males and females had similar FECs across their long lifespan, despite distinct differences in life-history strategy and clear sexual dimorphism. Additionally, although mothers invest two years in pregnancy and a further three to five years into lactation, nematode load did not vary with four different measures of female reproduction. Our results provide a much-needed insight into the host-parasite dynamics of a long-lived host; determining host-specific associations with infection in such systems is important for broadening our knowledge of parasite ecology and provides practical applications for wildlife medicine and management.

MHC, parasites and antler development in red deer: no support for the Hamilton & Zuk hypothesis.

The Hamilton-Zuk hypothesis proposes that the genetic benefits of preferences for elaborated secondary sexual traits have their origins in the arms race between hosts and parasites, which maintains genetic variance in parasite resistance. Infection, in turn, can be reflected in the expression of costly sexual ornaments. However, the link between immune genes, infection and the expression of secondary sexual traits has rarely been investigated. Here, we explored whether the presence and identity of functional variants (supertypes) of the highly polymorphic major histocompatibility complex (MHC), which is responsible for the recognition of parasites, predict the load of lung and gut parasites and antler development in the red deer (Cervus elaphus). While we found MHC supertypes to be associated with infection by a number of parasite species, including debilitating lung nematodes, we did not find support for the Hamilton-Zuk hypothesis. On the contrary, we found that lung nematode load was positively associated with antler development. We also found that the supertypes that were associated with resistance to certain parasites at the same time cause susceptibility to others. Such trade-offs may undermine the potential genetic benefits of mate choice for resistant partners.

FEEDING FREQUENCY ITS ACTION ON VIABILITY OF PRODUCTION AND PARASITE LOAD IN Pterophyllum scalare

Angelfish (Pterophyllum scalare) is a very important species in Brazil’s domestic market, enjoying feeding managements that differ from fish breeders to aquarists, so the cost of feed and labor become relevant items when cultivating the species. Thus, the objective of this work was to assess feeding frequency and feed deprivation based on growth performance, parasite infestation and cost-benefit in farming the species. The experiment was conducted in a completely randomized design in a 3x2 factorial scheme with 3 daily feeding levels, 4 meals, 2 meals and 1 meal; with and without feed deprivation and two repetitions. Feed deprivation consisted of offering feed 5 days a week only. Considering the performance, we observed that feeding once a day is the management of choice when the objective is maintaining fish weight. Feeding twice a day without deprivation and four times a day with or without feed deprivation resulted in higher growth performance than feeding once a day. Monogenean and nematode loads were not influenced by feeding management. The cost-benefit analysis enabled us to observe that the treatment with the best benefit was the one involving two feedings a day with no deprivation. Thus, considering the parameters mentioned above, we concluded that the treatment consisting of two daily feedings with no feed deprivation is the most adequate for farming this specie.

Disseminated strongyloides infection with Enterobius vermicularis and Streptococcus faecalis in an immunocompetent teenage UK resident

In 2005, a 13-year-old child presented with a 1-day history of fever and encephalopathy and later, abdominal pain. We report a case of strongyloides, one of only 17 cases reported in the UK that year. The presentation was consistent with a heavy strongyloides infection, seen occasionally with a high nematode load, in this case Enterobius vermicularis. It is an illness of the tropics and rare in an indigenous setting. We suggest that the diagnosis should be considered in children presenting with signs of sepsis.

Effect of feeding oak leaves (Quercus semecarpifolia vs Quercus leucotricophora) on nutrient utilization, growth performance and gastrointestinal nematodes of goats in temperate sub Himalayas

A 120 days of growth study was conducted on goats to assess the comparative effect of feeding two species of tanniferous oak leaves (Quercus semecarpifolia and Quercus leucotricophora) having varied levels of tannin on nutrient utilization, growth performance and gastrointestinal nematode load in goats. Eighteen crossbred (Chegu×Jamunapari) goats of 7–9 months old (body weight, 15.99±1.53kg) were divided into three groups of six in each in a completely randomized block design. Animals in all the three groups were fed similar concentrate mixture with different roughage sources (30:70). Animals were fed green grass (PS, Pennisetum clandestinum) in group T1 and oak leaves i.e. Quercus semecarpifolia (QS) and Quercus leucotricophora (QL) in groups T2 and T3, respectively. The level of condensed tannin (gkg−1 dry matter (DM)) was found to be more in QL (34) than QS (17), whereas the level of hydrolysable tannin (HT) (gkg−1 DM) was more in QS (61) than QL (31). A metabolic trial of six days duration was conducted after 90 days of growth trial. Dry matter intake (DMI) through roughage and total DM intake (gd−1) in oak leaves fed groups (T2 and T3) was higher (P<0.05) than grass fed group (T1). Feeding of QL in T3 had a depressing effect (P<0.05) on DM, organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and total carbohydrate (TCHO) digestibility as compared to feeding of PC. DM and OM digestibility were lower (P<0.05) in T2 fed QS whereas CP, NDF, ADF and TCHO digestibility were at par with control (T1). However, EE digestibility was higher (P<0.05) in T2. Daily nutrient intake per kilogram metabolic body weight in both the oak leaves fed groups was higher (P<0.01) than green grass fed group. Nitrogen and calcium balances (gd−1) and its efficiency of utilization were higher (P<0.05) in oak leaves fed group. Average daily gain (gd−1) was higher in T2 (32.5) and T3 (25.7) compared to T1 (13.5). Feed gain ratio (DMI/body weight gain) was better in T2 (22.9) than T1 (39.5) but at par with T3 (29.9) (P<0.05). Feeding of oak leaves (10–19gkg−1 DM CT in diet) significantly reduced (P<0.01) the gastrointestinal nematode load in goats. It can be concluded that feeding of oak leaves (Quercus spp.) to kids was beneficial in augmenting nutrient utilization, growth performance and feed efficiency as compared to animals fed green grass (PS). However, goats fed tannin (gkg−1 DM) with QS based diet (CT, 10; HT, 34) showed comparatively better performance than feeding of QL based diet (CT, 19; HT, 16).