Investigating the loss of recruitment potential in red grouse (Lagopus lagopus scoticus): the relative importance of hen mortality, food supply, tick infestation and louping-ill

In a recent paper in Journal of Animal Ecology, Laurenson et al. (2003) used an unreplicated experimental reduction in mountain hare (Lepus timidus Lath) numbers to test the importance of mountain hares in the persistence of louping-ill in a red grouse (Lagopus lagopus scoticus L.) population at a site in Morayshire. Their results confirmed that mountain hares are an important host of the sheep tick (Ixodes ricinus L.), and a vector of the louping-ill virus. They go on to show that a reduction in hare density was coincident with a reduction in tick numbers, a reduction in louping-ill seroprevalence in grouse and an increase in grouse breeding success. They concluded that, in the presence of mountain hares, ‘it may not be possible to take large harvests of red grouse’, and make moorland management for grouse uneconomic. Their case for mountain hares being important in the persistence of louping-ill is weakened by the lack of a rigorous experimental design but, moreover, they have failed to demonstrate that the removal of mountain hares has any effect on the potential harvest of red grouse, making their conclusions unreliable. We argue that the impact of louping ill on grouse dynamics, and the role that hares play in this, needs further investigation before any firm conclusions can be drawn or recommendations made for grouse-moor management with respect to the culling of mountain hares. Laurenson et al. set out to ‘test whether a reduction in hare densities leads to a decline in tick and louping-ill virus populations’. The authors acknowledge that an unreplicated treatment was not a satisfactory way to conduct such a test, but we would add that the problems associated with the lack of replication were increased by the absence of proper controls. The difference between a control site and a treatment site should be only in the treatment itself, with all other factors kept the same. In any large-scale field experiment, the choice of suitably paired sites is difficult, if not impossible, as sites will always differ in a variety of biotic and abiotic conditions, some of which may be very important. Both the control sites in this study are examples of just this problem: Control site 1, in Perthshire, was used for comparisons of louping-ill seroprevalence, and tick burdens in the red grouse population. Laurenson et al. stated that ‘tick numbers on grouse chicks decreased significantly on the treatment site between 1992 and 2001 in comparison to the control site’; and that ‘there was a significant reduction of louping-ill virus prevalence at the treatment site in comparison to the control site’. However, the management of this control site changed partway through the study, as the mountain hare culling regime changed in 1999. Louping-ill prevalence at control site 1 was also much lower than the treatment site even though the tick density was higher than the treatment site for much of the study period, suggesting that there were factors other than mountain hares involved in the relationship between tick numbers and louping-ill prevalence in red grouse. To look at the effect of mountain hare removal on overall tick numbers, a site adjacent to control site 1 was used for comparisons of tick burdens on the different vertebrate hosts present. However, this site received a poorer tick control regime on sheep than the treatment site, making the interpretation of the comparison impossible. Control site 2, in Inverness-shire, was used for comparisons of grouse breeding success and density with the treatment site. Several factors have been shown to be important in determining grouse breeding success and density, including climate, game-keeper density, soil quality and heather productivity (Hudson 1992, pp. 26–31), but the authors report only that the climate of the control site was similar to the treatment site. In addition, control site 2 is not an actual control, as the treatment is the reduction of louping-ill, while control site 2 has no louping-ill present at all. A true control would have had a high level of louping-ill throughout the study period, just like the treatment site before the treatment began. Controlling the analyses statistically is a suitable alternative to overcome the differences between sites that will occur inevitably in a large-scale field experiment. This is where the issue of replication becomes important. Controlling statistically for weather, tick host community, grouse food quality and quantity, etc. requires many sites rather than just the three that are reported. Laurenson et al. explain that large-scale replicated experiments on grouse-moors are logistically difficult and financially costly to run, both in terms of the manipulations themselves, and the disruption to normal moor management. We echo their concerns about the problems of replication in these types of experiment; however, where replication is not possible, proper controlling of the treatment site should be seen as essential. It is due to the combined problems of the unsuitability of controls and the lack of replication that, even before any results were obtained, Laurenson et al. were unlikely to be able to conclusively test whether a reduction in hare densities leads to a decline in tick and louping-ill virus populations. Red grouse populations are known to cycle through time with a period of between 4 and 9 years in the United Kingdom (Hudson 1992), although the mechanisms that drive the cycles (gut parasites or kinship aggression) are under dispute (Hudson et al. 2002; Mougeot et al. 2003). Laurenson et al. wanted to ‘examine the consequences of a reduction in louping-ill virus prevalence’ on breeding success and population density of red grouse. However, despite working over an 8-year period, they failed to take account of the underlying cycles in grouse abundance. Although Laurenson et al. did not set out testable hypotheses for the effect of louping-ill reduction on grouse breeding success and overall density, it is apparent from their discussion that they expected both breeding success and overall density to increase once louping-ill prevalence was reduced. Laurenson et al. showed that the difference in breeding success between the treatment site and control site 2 decreased after louping-ill seroprevalence declined to a low level (i.e. the treatment and control sites had similar levels of louping-ill, Fig. 2a in Laurenson et al.). However, no decrease in the difference between the sites in overall grouse density was found (Fig. 2b in Laurenson et al.), suggesting that louping-ill reduced red grouse breeding success, but not overall grouse numbers. This apparent paradox can be resolved easily by examining what the underlying null and alternative hypotheses should have been, in relation to the known patterns of red grouse population dynamics, rather than focusing solely on the tick–host–virus relationship. The sets of differential equations set out in Laurenson et al. and Gilbert et al. (2001) treat red grouse as a passive player, with populations of grouse pushed up or down by the level of disease present. However, we know that grouse numbers can vary cyclically, due to delayed density dependence, and therefore these dynamics should underpin any studies on the effects of louping-ill. The change in mean and median numbers of grouse from the amended Dobson & Hudson (1992) model, as louping-ill infection rate (i) increased. The distribution of grouse counts is skewed, so the median is a better estimator than the mean. The models of Dobson & Hudson (1992) are modified from Anderson & May's (1978) host–parasite model, and reproduce the observed cycles in grouse numbers over time through a delayed interaction with gut parasites. The gut parasite hypothesis has been verified experimentally (Hudson, Dobson & Newborn 1998). We use a modified version of the Dobson & Hudson (1992) model that incorporates the impacts of louping-ill on the population: dH/dt = (a − b)H − (αP + δP)P − δDH dW/dt = λP − γW − βWH dP/dt = βWH − (µP + b + αP)P − (αpP2/H)(κ + 1/κ) where H is the population size of grouse, W is the number of free-living parasite stages and P is the number of adult worms in the host. All parameters are taken from Dobson & Hudson (1992), except δD, which is the instantaneous reduction in recruitment due to louping-ill. As louping-ill affects chick survival particularly, we used δD to describe the effect of louping-ill. δD = a × i × m where a is the instantaneous birth rate of grouse, i is the infection rate of grouse chicks with louping-ill and m is the mortality rate of infected chicks; m has been shown to be around 80% in young grouse infected with louping-ill virus (Reid et al. 1978). We used this model to simulate time-series counts of red grouse under a number of levels of louping-ill prevalence (Fig. 1). An increase in louping-ill infection rate is associated with a lengthening of the grouse cycles and a narrowing of the range of grouse numbers towards the median value, which declines slightly as louping-ill infection rate increases (Fig. 2). This result matches that of Hudson & Dobson (2001): louping-ill dampens grouse cycles. Previously, it has been shown that the mean grouse numbers are reduced by the presence of louping-ill (Hudson et al. 2002), but because the distribution of grouse counts is heavily skewed, the median is the better estimator (Fig. 2). Results from the amended Dobson & Hudson (1992) model. The time series graphs show grouse numbers when (a) louping-ill is absent (i = 0%); (b) louping-ill is at moderate prevalence (i = 20%); and (c) louping-ill is at higher prevalence (i = 40%). In light of the above arguments, the mismatch between breeding success and total grouse harvests is resolved. We suggest that Laurenson et al.'s expectation of an increase in density of grouse upon removal of mountain hares appears not to be justified. Instead, we propose the testable hypothesis that a reduction in louping-ill virus would enhance the grouse population cycles, with an increase in maximum and a decrease in minimum grouse densities, and shorten the period of the cycles. This could be tested initially by characterizing the red grouse cycle length and amplitude on different moors and relating this to the level of louping-ill prevalence on each moor while controlling for other factors such as climate, keeper density and heather production. Grouse bag data are collated over a large number of moors (Hudson 1992), which should serve as a good resource this investigation. Grouse-moor management is of conservation importance, as without grouse shooting economic drivers may result in heather moors being converted to forestry or abandoned, thus losing some of their conservation interest (Thompson et al. 1995). Therefore, to maintain this important habitat, we agree with Laurenson et al. that grouse harvests must be economically viable. However, even if we accepted their methodology and results, the suggestion that louping-ill could make grouse harvests uneconomic is questionable. The model we present predicts that median numbers of grouse should be only slightly affected by louping-ill (Fig. 2), peak numbers may be reduced, but the cyclic lows may be less severe where louping-ill occurs. Hudson & Dobson (2001) suggest that grouse yields will be highest when dampening effects stop the population from oscillating, and that louping-ill can create such a dampening effect. Thus, it seems that louping-ill may not necessarily have a negative effect on grouse-moor economics as the minimum densities of grouse will be increased, and the time between nadir years will be greater (Fig. 1). While peak grouse numbers will be reduced, thus removing ‘bumper’ harvests, perhaps stability is the prudent approach to grouse-moor economics rather than cyclic boom and bust. The argument for reducing mountain hare numbers to keep grouse-moors economically viable in Morayshire has not been proven by the experiments of Laurenson et al. Before such management advice can be given with confidence, further work is required. While Laurenson et al. have put forward some evidence in support of a link between hare density, tick abundance and louping-ill seroprevalence, they fail to demonstrate a clear connection with grouse density and the viability of grouse-moors, on which they make recommendations. We have proposed an alternative relationship between louping-ill seroprevalence and grouse density from our model, and suggest that the consequences for grouse-moor economics need further investigation. We concur with Laurenson et al.'s approach using experiments to test theoretical explorations: large-scale field experimentation in animal ecology is commendable. However, experiments must be replicated and suitably controlled to rigorously manipulate the system and produce robust results and conclusions.

Red grouse Lagopus lagopus scoticus populations exhibit unstable dynamics that are often characterised by regular periodic fluctuations in abundance. Time‐series’ of grouse harvesting records collected from 287 management units (moors) across Scotland, England and Wales were analysed to investigate the broad scale patterns of synchrony in these fluctuations. Estimation of the spatial autocorrelation of grouse population dynamics across moors indicates relatively high levels of synchrony between populations on adjacent moors, but that this synchrony declines sharply with increasing inter‐moor distance. At distances of greater than 100 km, grouse population time‐series exhibit only weakly positive cross‐correlation coefficients. Twenty‐eight geographical, environmental and other candidate variables were examined to construct a general linear model to explain variation in local synchrony. Grouse moor productivity (average size of shooting bag), distance from the Atlantic coast moving in a north‐easterly direction, April and June temperatures, and June rainfall significantly increased the explanatory power of this model. An understanding of the processes underlying synchrony in red grouse population dynamics is a prerequisite to anticipating the effects of large‐scale environmental change on regional patterns of grouse distribution and abundance.

One of the most important measures of offspring performance is growth rate, which is often traded off against another important survival trait, immune function. A particular feature of ostrich chicks maintained in farmed environments is that cohorts of chicks vary widely in size. As parents can have a profound effect on the phenotype and fitness of their offspring, we investigated whether chick growth and immune defence were related to variation in levels of immune defence in their genetic parents. As secondary sexual traits of sires could serve as indicators of male quality, and be used in female mating decisions, we also investigated whether chick growth rate and immune defence were related to male plumage and integumentary colouration. We found that offspring growth rates and humoral responses were related to the humoral responses of their parents, suggesting that at least some components of humoral immune capacity are heritable. The white colour of male ostrich feathers was correlated to the humoral response and growth rate of their offspring, suggesting that this visual cue involved in the male courtship display could serve as an important signal to females of male quality, thereby forming the basis of mate choice in this species.

Background: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease that is endemic in Africa, southeastern Europe, and Asia. Ticks are both the reservoir and the vector of the CCHF virus (CCHFV). Determining the virus infection rate of the tick population in different geographical regions is necessary todesign public health policies to prevent CCHF outbreaks. Objectives: To determine the prevalence, seasonal activity, and the frequency of CCHFV infection of the tick population in Hamadan province of west Iran. Methods: This cross-sectional study was conducted in 3 counties of Hamadan Province from June 2013 to May 2014. The study areas included both lowland (plains) and highland (mountains) and covered 5% of the villages where 10 herds per village of sheep and goats were randomly selected for hard tick collection. Results: We examined 983 sheep and goats, and 881 ticks were collected and identified before being preserved for molecular tests. The collected ticks belonged to 3 genera including, Rhipicephalus (95.6%, n = 842), Hyalomma (4.1%, n = 36) and Haemaphysalis (0.4%, n = 4). After species identification, 100 randomly selected ticks were analyzed using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect viral infection. CCHFV infection was observed in 7 collected ticks, of which 4 belonged to R. sanguineus, 2 belonged to R. bursa, and one Hy. asiaticum. Conclusions: Hyalomma and Rhipicephalus ticks are the main vectors of CCHFV in Hamadan province where CCHF is focal and endemic. Keywords: Crimean-Congo hemorrhagic fever, Hamadan, Iran, molecular epidemiology, tick-borne diseases, zoonotic viral disease

Growth and survival of altricial young are influenced by their parents’ abilities to invest in a breeding attempt. As a result, chick growth and survival in one breeding season may be indicative of their parents’ long-term reproductive potential. To determine whether variation in long-term reproductive success is driven by differential breeding investment, parental care and chick growth in wandering albatrosses (Diomedea exulans) were correlated with parental historical reproductive success. Effects of age and breeding experience (determined from past breeding attempts) and pre-laying body condition (mass–size indices) on chick growth and survival also were tested. Longer brooding of chicks increased their survival, but length of chick brooding did not differ between historically unproductive and successful breeders. Past reproductive success also was not correlated with chick growth rates or fledging mass or size. Chick brooding period, chick growth rates, final mass and size were independent of parental body condition. Older and more experienced parents brooded chicks for longer and their chicks grew faster, supporting previous findings that breeding competence is a learnt skill. Chick care and growth characteristics differed more between than within pairs, suggesting that differences in these characteristics are driven by variation among pairs.

Communal farmers in most African countries have used both indigenous and modern knowledge to control ticks and tick-borne diseases. The aim of this paper is to report on the communal farmers’ perceptions on the use of indigenous knowledge in controlling ticks and tick-borne diseases (Anaplasmosis) of cattle in the Katima Rural Constituency, Zambezi Region Namibia. The data was collected using structured questionnaires and analyzed as percentage of the participants. The results show that 85% of the participants are aware of the existence of ticks and tick-borne diseases affecting cattle in the study area and this suggests that the problems are evident in the area. It was also found that the roots, leaves and bark extracts of Muhonono (Terminalia sericia), Mukolotela (Piliostigmathonningii), Muchoko/Itanga (shrub) and Umbwiti/Ligwatanga (shrub) are often used by the farmers in the ethno-veterinary control of ticks and tick-borne diseases. This practice is evident among the older age bracket (51 – 70 years), with the 61 – 70 years old participants indicating complete reliance on the use of ethno-medicine to control their cattle’s ticks and tick-borne diseases. Even though, there is an existing government policy that compels all farmers to vaccinate their animals against all sorts of livestock diseases in order to supply healthy meat to the markets, the financial cost of utilizing the conventional methods appears to be beyond the reach of most of the communal farmers. This effect will continue to promote the use of ethno-medicine in the control of ticks and tick-borne diseases in the study area. Therefore, there is need for government veterinary department to work with the communal farmers in identifying and standardizing the plant extracts for wider applications in controlling cattle’s ticks and tick-borne diseases.

Parasites Can Regulate Wildlife Populations

Extant populations of Irish red grouse (Lagopus lagopus hibernicus) are both small and fragmented, and as such may have an increased risk of extinction through the effects of inbreeding depression and compromised adaptive potential. Here we used 19 microsatellite markers to assay genetic diversity across 89 georeferenced samples from putatively semi-isolated areas throughout the Republic of Ireland and we also genotyped 27 red grouse from Scotland using the same markers. The genetic variation within Ireland was low in comparison to previously published data from Britain and the sample of Scottish red grouse, and comparable to threatened European grouse populations of related species. Irish and Scottish grouse were significantly genetically differentiated (FST = 0.07, 95% CI = 0.04–0.10). There was evidence for weak population structure within Ireland with indications of four distinct genetic clusters. These correspond approximately to grouse populations inhabiting suitable habitat patches in the North West, Wicklow Mountains, Munster and Cork, respectively, although some admixture was detected. Pair-wise FST values among these populations ranged from 0.02 to 0.04 and the overall mean allelic richness was 5.5. Effective population size in the Munster area was estimated to be 62 individuals (95% CI = 33.6–248.8). Wicklow was the most variable population with an AR value of 5.4 alleles/locus. Local (Munster) neighbourhood size was estimated to 31 individuals corresponding to an average dispersal distance of 31 km. In order to manage and preserve Irish grouse we recommend that further fragmentation and destruction of habitats need to be prevented in conjunction with population management, including protection of the integrity of the existing population by refraining from augmenting it with individuals from mainland Britain to maximise population size.

Several tick-borne infectious diseases that can affect children are prevalent in different geographic areas within the United States. Examples of these include: babesiosis, a protozoal infection transmitted by the deer tick(Ixodes scapularis); Colorado tick fever, which is an arboviral infection; and tularemia, a Gram-negative bacterial infection. Several rickettsial diseases also are spread by tick bites, including ehrlichiosis,which is spread by the tick vector Amblyomma americanum and possibly Ixodes scapularis, and Rocky Mountain spotted fever (RMSF). RMSF is transmitted in the South Atlantic/Southeastern states primarily by the dog tick Dermacentor variabilis, in the Western United States by the wood tick Dermacentor andersoni, and in the South Central region by the Lone Star tick, Amblyomma americanum.Perhaps the most notorious tick-borne disease in the United States today is Lyme disease, caused by the spirochete Borrelia burgdorferi. The disease is transmitted by the deer ticks Ixodes scapularis(previously Ixodes dammini) in the East/ Midwest and Ixodes pacificus in the West.Control measures for these and other tick-borne pediatric infectious diseases are aimed at preventing infected ticks from biting children. These measures include avoiding tick-infested areas; wearing protective clothing that covers exposed parts of the body; using tick/insect repellant; and carefully examining the child’s head, neck, and body following possible tick exposure.Any ticks that are discovered should be removed promptly either by using the fingers or fine tweezers. Whatever method is used, the tick should be grasped as close to the skin as possible and removed by pulling straight out. Twisting motions should be avoided. In addition, care should be taken not to squeeze the body of the tick. Fingers always should be protected by tissue paper and thoroughly washed with soap and water after tick removal.Adherence to the measures described can diminish the transmission of tick-borne diseases by reducing contact with ticks and preventing infected ticks from biting and engorging on children.Worldwide, only mosquitoes surpass ticks as arthropod vectors of human infections, and the range of infectious agents transmitted by ticks to people is an unfortunate reflection of nature’s almost infinite variety: virus, bacterium,protozoa, rickettsia, and spirochete,not to mention the noninfectious neurotoxin that causes tick paralysis. Children are particularly susceptible to tick-borne disease because they love to play in the kinds of places where ticks live, as do their pets,another common source of exposure.An article published in Pediatrics(Needham GR. Evaluation of five popular methods for tick removal. 1985;75:997) serves as the scientific basis for the recommendations outlined by Dr Ozuah. Despite what our grandmothers may have told us,neither petroleum jelly, fingernail polish, alcohol, nor a hot match works as well in extracting a tick intact as totally straight traction. Dr Ozuah points out that if fingers are used instead of tweezers, they should be protected by tissue or rubber gloves to keep infectious agents in the tick’s saliva from invading through breaks in the skin—an argument for not allowing children to “de-tick” their pets.Because of the risk of contamination with infectious agents from the tick’s saliva, the site of a bite should be disinfected carefully after the tick has been removed. Removed ticks should be put into a bottle of alcohol or flushed down the toilet.

三種の処理法,すなわち熱水処理,熱アルコール処理およびオートクレーブ処理が,菜種粕の特異作用防止に対する効果を調べるために,各処理粕を10%配合した飼料を給与したシロネズミについて,おもに成長および甲状腺におよぼす影響を,無処理粕給与の場合と比較検討した.またハツカネズミでの予備試験により,菜種粕の特異作用の程度が,去勢によつて変化することが認められたので,これについても同時に調べた.三種の処理のうち,熱水処理のみが著しく有効で,特異成分は,大部分除去されたか,または不活性化されたものと推定された.すなわち,同じように10%配合しても、無処理粕に比べて,熱水処理粕の場合には,嗜好性および成長が良好で,甲状腺の肥大も見られず,その組織像もほとんど正常であつた.また肝および腎の肥大も認められなかつた,これに反して,熱アルコールおよびオートクレーブ処理は,おおむね無効であつた.なお,無処理粕を与えたシロネズミの雄では,甲状線は肥大したが,成長は阻害されなかつたのに対し,雌では,甲状腺のみならず成長に対する特異作用もあらわれ,性別による差があることが認められた.去勢した場合には,菜種粕の特異作用はあらわれ得ないものであろうと推定される結果を得た.このことから,性ホルモン投与による化学的去勢によつて,特異作用を軽減できるのではないかと考えられた.

The purpose of the present experiment, using chicks instead of rats in authors' previous studies, was to confirm the advantageous effect of hot-water treatment in counteracting the maleficence of rapeseed oilmeal (abridged as RSOM hereafter), and further to confirm whether or not there is any sexually different response to the maleficence of RSOM.Sixty male chicks of day-old White Leghorn were used in the first experiment (I) and 100 females of the same breed in the second (II) respectively. Both groups of chicks, subdivided into 4 subgroups in I and 5 subgroups in II, were fed the respective rations for 4 weeks of which formulae and chemical compositions were given in Table 1 and 2.In experiment I, the growth rate of male chicks in each subgroup was almost similar. No significant differences between control and other three treated subgroups were observed.In experiment II with female chicks, on the contrary, an advantageous effect of hot-water treatment on growth was observed. The growth of female chicks fed a ration contain 10per cent of untreated RSOM was markedly retarded, the differences in weight gain being found to be highly significant (P<0.005) between control and untreated RSOM group. Almost no growth depression, however, was observed in the subgroups fed rations containing treated RSOM. It was further shown that the growth rates of chicks in two subgroups receiving hot-water extract of RSOM were promoted than that of none added group.In the male chicks, the advantageous effect of hot-water treatment in preventing enlargement of thyroid gland was not clearly revealed but it was remarkable in the females. As shown in Table 4, the thyroid weight of females in three subgroups which received rations containing untreated RSOM or its hot-water extract increased significantly (P<0.001) than that in control, whereas that was not remarkably shown in hot-water treated RSOM group.As mentioned above, there was a sexually different response to the specific effect of RSOM on either growth or thyroid gland, e. g. the female chicks were more sensitive than males to the specific effects of the oilmeal.These findings are in good accord with those of former experiments with rats which have been reported in authors' previous papers1, 2, 3, 5, 8). Consequently it is indicated that our possible interpretation2, 3) for the specific factors contained in RSOM is applicable to chick.The reduced glutathione levels in liver of male chicks receiving untreated RSOM or its hot-water extract were higher (P<0.05) than those of chicks in basal group.

The two experiments were carried out to study the effect of vitamin B12 on the growth rate of chick, and the egg production and the hatchability of laying hen.(1) White leghorn hens were fed either low vitamin B12 layer diet, which consists of corn starch, meal and soybean oil, or high vitamin B12 layer diet, which was enriched with 10μ of vitamiu B12 per kg of the low vitamin B12 layer diet.The efficiency of vitamin B12 had no influence on egg production, egg weight, feed consumption and viability of the hens. Moreover, no difference in hatchability was observed between the fertile eggs of hens on low vitamin B12 diet and that on high vitamin B12 diet, although vitamin B12 content in the former was much low than that in the latter.(2) The additional effect of vitamin B12 (10μg/kg) and DL-methionine (0.4%) to the low vitamin B12 and low methionine starter diet was examined on the growth rate of the chicks, which were offsprings of breeding hens fed either low vitamin B12 layer diet or high vitamin B12 layer diet.Additional vitamin B12 to both of low vitamin B12 layer and starter diets was effective to improve growth rate of the chicks. The additional effect of methionine on the chick growth was significant, although the interaction between vitamin B12 and methionine on the growth rate of chick was not recognized. The feed conversion was improved by addition of either vitamin B12 or methionine to low vitamin B12, low methionine starter diet. Possitive correlation was observed between the amount of vitamin B12 in the chick liver and growth rate of chick.

Epidemiology of Tick Bites and Borreliosis in Children Attending Kindergarten or So-Called “Forest Kindergarten” in Southwest Germany

The growth in ecotourism and nature-based recreational activities in China has resulted in an increased frequency of visits to green spaces, thereby elevating exposure to ticks and the subsequent risk of tick-borne diseases. This study comprehensively investigate individual behavioral and cognitive factors associated with the risk of contracting tick-borne diseases to facilitate the development of effective prevention and control strategies, supporting public health initiatives in high-prevalence regions. We conducted an extensive questionnaire survey among 3000 residents from three northeastern provinces in China (Heilongjiang, Jilin, and Liaoning), where tick-borne diseases exhibit relatively high prevalence. The survey focused on gathering information regarding participants' tick bite history, perception of tick-borne disease risks, and outdoor activity patterns. Using structural equations analysis, we explored the pathways and strengths of the associations between these factors. Our findings revealed an average self-reported tick bite rate of 14% among the participants. Notably, tick-borne encephalitis exhibited the highest self-reported prevalence of infection (4%) among tick-borne diseases, while both Lyme disease and Severe fever with thrombocytopenia syndrome had a prevalence of 2%. The average rate of tick bites among respondents' pets was 14%, with bites predominantly located on the ears, back, and abdomen. The strongest correlation was observed between tick bite rate and subsequent infections, emphasizing its role as the primary contributing factors to infectious status. Moreover, our results indicated that the causal structure of tick-borne disease infections varied across different cities, underscoring the significance of considering the ecological environment and regional knowledge on ticks. This study provides valuable insights into the current landscape of tick-borne disease infections in northeast China and identifies potential behavioral and cognitive factors, an aspect that has not been previously investigated. Our findings enable predictions on the future impact of knowledge dissemination efforts and improved urban facilities on mitigating tick bites and reducing tick-borne disease infections.

Rising burden of immature sheep ticks (Ixodes ricinus) on red grouse (Lagopus lagopus scoticus) chicks in the Scottish uplands.