Genetic differences of Ascaridia galli egg output in laying hens following a single dose infection.

Groups of 20-week-old white (Lohmann LSL) and brown (Lohmann Brown) hens were reared under helminth-free conditions and both divided into two subgroups. One subgroup was artificially infected with 250 embryonated Ascaridia galli eggs, the other subgroup were kept as uninfected controls. During the following 12-month laying period individual faecal Ascaridia egg counts (FEC) were performed and bodyweight measured at monthly intervals. Laying performance and egg weights were determined daily. The mean FEC were significantly (P < 0.01) higher in infected white hens than in infected brown hens. The growth rate of the white hens was significantly (P < 0.05) higher in the control group, whereas in brown hens no significant group difference was observed. The laying performances and egg weights did not differ significantly (P > 0.05) between control and infected animals for either line. The estimated repeatabilities for mean log(10) FEC of different samples were reasonably high (0.16-0.54). Heritabilities for mean log(10) FEC were between 0.13 and 0.19 for white hens and between 0.0 and 0.10 for brown hens. Thus, it should be possible to select for A. galli resistance in chickens, which will be of importance for birds kept in alternative and organic farming systems.     

Age-related differences of Ascaridia galli egg output and worm burden in chickens following a single dose infection

Ninety white chickens (Lohmann LSL) were reared under helminth-free conditions and divided into five groups. Four groups were artificially infected with 250 embryonated Ascaridia galli eggs at the age of 6, 12, 18 or 24 weeks. Ten birds were kept as uninfected controls. Six and 10 weeks after infection (p.i.), individual faecal egg counts (FEC) were performed. The birds were slaughtered after the second sampling and their gastrointestinal tracts were examined for the presence of adult A. galli. The FEC increased from the first to the second sampling significantly in all the infected groups. The highest increase was shown in the group infected at 12 weeks of age, whereas the increase in the other groups was relatively moderate. However, the total worm burden and mean FEC at the second sampling were highest (p<0.01) in those birds infected at an age of 12 or 18 weeks. The serum protein and triiodothyronine (T3) levels did not differ significantly (p>0.05) between any of the groups. Thyroxine (T4) was significantly different between the groups infected at 6 and 18 weeks of age (p<0.05), and those at 6 and 24 weeks of age (p<0.01). The thyroid hormone levels correlated significantly with the FEC. Age does not seem to play a major role in resistance to A. galli infections in layers, whereas a bird's hormonal and immune status, related to laying activity, seems to have a significant negative impact on resistance.     

Genetic resistance to natural helminth infections in two chicken layer lines

Groups of Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL) hens were reared under helminth-free conditions and kept afterwards together in a free range system. Mortality rate, body weight development, laying performance and faecal egg counts (FEC) were recorded during a 12 month laying period. At the end of the laying period, 246 LSL and 197 LB hens were necropsied and worms counted following the World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines. In addition adult Heterakis gallinarum and Ascaridia galli were sexed and measured for length. Significant (P<0.01) differences were observed in mortality rates between LSL and LB animals (12.9 vs. 5.7%). LSL hens showed significantly (P<0.05) higher FEC when compared with LB hens at almost all dates of monitoring. Almost all animals became infected with at least one helminth species. The most prevalent species were H. gallinarum, Capillaria spp. and A. galli. LB hens showed a significantly (P<0.05) higher average number of adult H. gallinarum, Capillaria spp. and tapeworms when compared with LSL animals. However, number of adult A. galli was in tendency lower in these animals. In total, LB had a significantly (P<0.05) higher worm burden than LSL (192.3 vs. 94.3). The estimated heritabilities for total worm burden were 0.23 (SE±0.12) in LSL and 0.75 (SE±0.21) in LB, respectively. The number of all different helminth species were positively correlated. The sex ratio of H. gallinarum and A. galli and the average worm lengths were not significantly (P>0.05) different between the genotypes. There was no significant phenotypic correlation between body weight and worm burden in LSL, whereas it was the case in LB (r=0.17, P<0.05). Based on the estimated heritabilities it is possible to select for helminth resistance in both genotypes.     

Response of two breeds of chickens to Ascaridia galli infections from two geographic sources

Comparative resistance to different isolates of Ascaridia galli was investigated in a local chicken breed from Jordan (LC) and in the Lohmann LSL white chicken (LW) strain. In two trials, birds of LC and LW were inoculated orally at 1-day old with 250 embryonated A. galli eggs. In the first trial a German source of A. galli was used, whereas in the second trial, a Jordan source of A. galli was used. At week 7 of infection, infected LC birds harbored significantly (P<0.05) fewer worms and excreted less A. galli eggs than infected LW birds. A. galli isolated from Jordan were less infectious than A. galli from Germany. Results suggest that the variation in genetic background between LC and LW is involved in the resistance to A. galli infection. A. galli isolates from different geographic areas differ in their ability to infect different chicken genotypes.     

Influence of Dermanyssus gallinae and Ascaridia galli infections on behaviour and health of laying hens (Gallus gallus domesticus)

(1) The effect of infections with Dermanyssus gallinae (poultry red mite or chicken mite) and Ascaridia galli (roundworm) on the behaviour and health of laying hens was investigated. (2) Six groups of 15 pullets (Isa Brown) were kept in indoor pens from 18 weeks of age. Two groups were artificially infected with D. gallinae, two groups with A. galli and two groups were kept as uninfected controls. The hens were observed for behavioural reactions and physiological changes (weight gain and various blood variables) to the parasitic infections. (3) Infections with D. gallinae resulted in reduced weight gain, anaemia and even death of some of the hens. Behavioural changes were also observed, as the mite-infected hens showed higher self-grooming and head scratching both during the day and night. (4) A. galli resulted in a lower weight gain but no significant changes were seen in blood variables or behavioural activities.     

Anthelmintic effects of citrus peels ethanolic extracts against Ascaridia galli

The use of phytogenic bioactive compounds to control poultry helminthes is increasing in different production systems. In vitro and in vivo anthelmintic activity of citrus peels against Ascaridia galli was investigated. Ethanolic extracts of three citrus peels species were suspended in 0.5% dimethyl sulfoxide (DMSO) to form an experimental composition (EC). EC was mainly composed of Limonene (96%), followed by β-Pinene (1.5%), α-Pinene (0.5%), and Sabinene (0.3%). For in vitro investigation, adult A. galli worms (n=225) were collected from naturally infected chickens and distributed to 3 equal groups. Groups 1, 2, and 3 were exposed to Fenbendazole (0.5mg/ml), EC (50mg/ml), and 0.5% DMSO, respectively. For in vivo investigation, 200 Lohmann Selected Leghorns chicks were infected at 1-day old with 250 embryonated A. galli eggs. At 6 weeks of age, 150 A. galli infected birds were randomly allocated into 5 equal groups. Groups 1, 2, and 3 were treated with 300, 600, and 1200 mg EC kg(-1) body weight, respectively. Group 4 was treated with Fenbendazole (50 mg kg(-1)). Group 5 was left as control. Birds were euthanized 2-weeks post-treatment, and all worms were collected from their intestines. EC possessed significant (P<0.001) in vitro anthelmintic properties on live worms. No significant (P>0.05) difference was quantified between number of motile worms exposed either to EC or Fenbendazole 7h post-exposure. A significant (P<0.0001) reduction in fecal egg count was observed 14 days post-treatment with 1200 mg kg(-1) EC. No significant differences were observed in worm burden of the 300 mg EC-treated group compared to the controls. In contrast, the 600 and 1200 mg EC-treated groups showed significant (P<0.0001) reduction in worm burden. Fenbendazole was the most effective in reducing A. galli burden (Efficacy=97%) followed by 1200 mg EC kg(-1) (68%), 600 mg EC kg(-1) (66%), and 300 mg EC kg(-1) (5%). It is concluded that citrus peels extracts have potential anthelmintic properties against A. galli.     

A coprological and serological survey for the prevalence of Ascaridia spp. in laying hens

Ascaridia galli is a common nematode found in the intestine of domesticated chickens. The objectives of the study were to conduct a coprological and serological survey on the prevalence of ascaridiosis in laying hens of commercial farms. The farms recently adopted a breeding programme, where the hens have access to outdoor pens. Different amounts of Ascaridia eggs were detected in five of seven studied farms, while the other two farms were found to be free from the parasite. Serological tests revealed a seroprevalence of 21.8% (range 7.6-95%). No positive serum samples were detected in the same farms with previous negative coprological analysis. Western blot analyses confirmed the results obtained by the enzyme-linked immunosorbent assay (ELISA) test. In four experimentally infected hens, a progressive increase of the IgG antibody levels was observed, surpassing the cut-off point established for ELISA test 6 weeks post-infection. Serological tests are able to detect the infection before the eggs of the parasite appear in the faeces of infected hens, providing a useful tool to detect infections with Ascaridia spp. in avian farms.     

The effect of concurrent infections with Pasteurella multocida and Ascaridia galli on free range chickens

Pasteurella multocida and Ascaridia galli are observed with high prevalences in free range chickens in Denmark, but the impact is unknown. A study was carried out to examine the interaction between A. galli and P. multocida in chickens and the impact on production.Five groups, each with 20 18-week-old Lohmann Brown chickens were infected. Group 1 was orally infected with 1000+/-50 embryonated A. galli eggs. Group 2 received 10(4) cfu P. multocida intratracheally. Group 3 was infected with A. galli and subsequently with P. multocida. Group 4 was infected with P. multocida followed by A. galli. Group 5 was the control. The study ran for 11 weeks where clinical manifestations, weight gain and egg production were recorded. Excretion of P. multocida was determined on individual basis and blood smears were made for differential counts. At the end of the study pathological lesions and the number of adult worms, larvae and eggs in the faeces were recorded.The birds were more severely affected when infected with both pathogens compared to single infections with A. galli or P. multocida, respectively. A lower weight gain and egg production was observed with dual infections. A. galli infection followed by a secondary P. multocida infection resulted in more birds with pathological lesions and continued P. multocida excretion.In conclusion a negative interaction between A. galli and P. multocida was observed and it is postulated that free range chickens are at higher risk of being subjected to outbreaks of fowl cholera when they are infected with A. galli.     

Effect of furnished small group housing systems and furnished cages on mortality and causes of death in two layer strains

1. Mortality and causes of death were recorded over two trials with 13045 Lohmann Selected Leghorn (LSL, white layer strain) and 4410 Lohmann Brown (LB) laying hens kept in furnished small group housing systems and furnished cages. In trial 1, hens were housed from weeks 19 to 71 (LSL) and 17 to 69 (LB). In trial 2, LSL hens were housed from weeks 18 to 57. 2. The hens were kept in groups of 40 and 60 in the furnished small group housing system Eurovent 625 + a-EU and in groups of 10 and 20 in the furnished cages Aviplus and Eurovent 625A-EU. 3. To investigate the possible effect on mortality of rearing the birds on litter floors or in cages, in trial 2 half of the LSL hens were reared on the floor and half in conventional cages. 4. Mortality was greater in the Eurovent furnished small group housing system (5.2%) than in the furnished cages Aviplus (4.0%) and Eurovent (4.2%). 5. Mortality was also affected by the interactions among housing system and trial, layer strain and rearing. In trial 1, more LB laying hens died in the Aviplus system than in the Eurovent group system. There was no significant difference in mortality of the LSL laying hens between housing systems in trial 1. In trial 2, mortality of the LSL hens was greater in the group housing system (hens reared on litter floors: 10.1%; hens reared in cages: 2.8%) than in the furnished cage Aviplus (hens reared on litter floors: 6.0%; hens reared in cages: 1.5%). 6. Mortality was greater in floor-reared LSL laying hens than in the LSL laying hens reared in conventional cages. 7. Group size within housing system had no significant effect on mortality. 8. The most common findings at autopsy were different types of cannibalism (65.51%), with vent cannibalism (38.57%) the most common.     

Effects of a high oil and fibre diet and supplementary roughage on performance, injurious pecking and foraging activities in two layer hybrids

1. The study investigated the feeding of a high oil and fibre diet containing 260 g/kg organically produced cold pressed sunflower cake or supplemental roughage to aviary-housed Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) layers between 20 and 74 weeks of age with outdoor access during summer. 2. Feeding roughage was associated with reduced vent injuries, a tendency to improve plumage condition, and was accompanied by improved FCR compared with controls. Feeding the high oil and fibre diet tended to improve FCR compared with the control diet. 3. The dry matter of faeces was reduced in both treatments compared with controls. Foot pad cleanliness and the proportion of dirty eggs were negatively affected by the high oil and fibre diet. Foot health was superior in LB compared to LSL. 4. LB used the outdoor hen-runs more than LSL, but LSL consumed more litter indoors. Fewer LB hens fed on the control feed were recorded in the outdoor hen-runs. Supplemental roughage tended to decrease litter consumption. 5. In conclusion, supplemental roughage reduced vent injuries and was correlated with foraging activities. Feeding 260 g/kg sunflower cake negatively affected hygiene in aviary hens. Sunflower cake is nevertheless a promising alternative feedstuff to fulfil the protein requirement in organic layers.     

Flubendazole: safety regarding egg production and reproductive performance of breeder chickens

In a comparative field trial, 5,950 meat breeder chickens were medicated via feed for 7 consecutive days with 60 ppm of the anthelmintic flubendazole. This treatment cured the birds of an infection with Ascaridia galli and Capillaria obsignata. A slight but transitory diarrhea was observed in treated chickens. The applied medication did not unfavorably affect egg production, fertility, or hatchability.     

Host age only partially affects resistance to primary and secondary infections with Ascaridia galli (Schrank, 1788) in chickens

Two experiments were conducted to compare the effect of chickens' age on resistance to primary and secondary infections with Ascaridia galli. In Experiment I, three groups, each of 80 female Lohman Brown chickens, aged one day, one month, or four months were compared. Within each group, 54 chickens were infected orally with 500 embryonated eggs and 26 were kept as non-infected controls. Weights were recorded weekly and five chickens in each group were slaughtered every 2 weeks for worm counts. At week 10 post-infection, 17 of the infected chickens and 18 of the controls were challenged with 500 eggs. In a replicate experiment (Experiment II), 35 one-day-old and 53 one-month-old female Lohman Brown chickens were infected orally with 500 A. galli eggs. Weights and fecal egg counts were recorded every week and infected chickens were necropsied every two weeks for determination of the worm burden. Chickens infected at one month of age excreted significantly fewer A. galli eggs when measured at 14 weeks of inoculation. The worms recovered from the one-month-old age group were significantly shorter than those from the chickens infected at one day of age in the first experiment. Worm burden and female fecundity values, however, were not significantly different between age groups in both Experiments I and II. Weight gains of infected chickens were not significantly different from the controls' and only a few chickens exhibited occasional slight diarrhea in both experiments. The results from these experiments demonstrate that the chickens' age only partially influences resistance to A. galli infection.     

The effect of Plasmodium gallinaceum on a challenge infection with Ascaridia galli in chickens

The effect of a primary infection with the haemoparasite Plasmodium gallinaceum on the establishment of a challenge infection with the nematode Ascaridia galli in chickens was studied. Four groups were infected as follows. Group 1: inoculated intravenously with 10(6) P. gallinaceum-infected erythrocytes on day 0; group 2: orally infected with 500 embryonated A. galli eggs on day 10; group 3: infected with P. gallinaceum on day 0 and A. galli on day 10; and group 3: non-infected control birds. The results of this investigation demonstrates that a primary infection with P. gallinaceum in chickens alters the course of a subsequent infection with A. galli. Thus, an antagonistic effect was seen in which the malaria infection caused a significant reduction on the establishment of the nematode in concurrently infected animals.     

Comparative efficacy of flubendazole and a commercially available herbal wormer against natural infections of Ascaridia galli, Heterakis gallinarum and intestinal Capillaria spp. in chickens

The efficacy of a commercially available flubendazole-based product and a commercially available herbal product were compared against three species of helminth parasites of chickens: Ascaridia galli, Heterakis gallinarum and Capillaria spp. A total of 48 naturally infected chickens were used in the study with 16 birds in each of three treatment groups (untreated control; flubendazole; and a herbal product). One bird from each treatment group was necropsied on Day 0 prior to first treatment to confirm the parasite species present in the birds. Treatments were administered as labelled and the 45 remaining birds were necropsied on Day 12 and worm counts performed. Average worm counts in the two treated groups were compared to the untreated controls to calculate efficacy. Flubendazole (Group A) achieved an overall efficacy of 99.4% for the three parasite species. The herbal product (Group B) achieved efficacies ranging from less than zero to 11.6% for the three parasites, with worm counts not significantly different to the untreated controls. At present, commercially available herbal products claiming anthelmintic properties do not require licencing as veterinary medicinal products (Directive 2004/28/EC: see Article 17 and 33-38) and thus are not required to meet specific efficacy thresholds. Products which do not appear to deliver acceptable anthelmintic efficacy, are obviously a concern from many aspects but specifically from an animal welfare perspective.     

Ivermectin as a bird anthelmintic--trials with naturally infected domestic fowl

To evaluate the use of ivermectin as a bird anthelmintic, 29 White Leghorn hens naturally infected with Ascaridia spp., Heterakis spp. and Capillaria spp. were treated with 0.2, 2 or 6 mg/kg intramuscularly or 0.2 or 0.8 mg/kg orally. Faecal samples were collected before treatment and at autopsy, 2, 6, or 16 days after treatment, when the intestines were also examined for helminths. None of the treatments gave satisfactory anthelmintic results.     

Genetic resistance to Ascaridia galli infections in chickens.

Ascaridiosis is still a cause of economic losses in modern poultry production systems. Improving genetic resistance to this disease provides an attractive alternative for free-range organic poultry producers and will eventually reduce the extensive use of anthelmintic drugs. An experiment was conducted to compare resistance to Ascaridia galli infections in Lohman Brown (LB) and Danish Landrace (DL) chickens. A self-cure mechanism to A. galli infections was observed in both breeds. However, significantly higher worm burdens and egg excretion were seen in the DL compared to LB chickens during primary infection. This indicates that breeding for resistance to A. galli is possible in chickens.     

Effect and repeatability of Ascaridia galli egg output in cockerels following a single low dose infection

Three groups of caged 20 Tetra-SL cockerels aged 1 day were orally infected with 30, 60 or 125 embryonated Ascaridia galli eggs. After 11, 12 and 13 weeks, faecal egg counts (FECs) were determined. All birds were slaughtered after the last sampling. A group of 25 control birds was sampled and slaughtered in parallel. The gastrointestinal tracts were examined for the presence of adult stages of A. galli. A random sample of 10% was also examined for the presence of immature stages of A. galli. The group with an infection dose of 125 eggs showed the highest average worm burden (p<0.05) and number of females (p<0.05), but the mean establishment rate was the lowest in this group. There was no significant difference in the mean logFEC between the groups. The logFEC per female worm was the highest in the low infection group (p<0.05). The average worm length and weight and the birds body weight were not significantly different among the groups. The estimated repeatabilities for mean logFEC of the different samples were reasonably high (0.55-0.87). This may open a way of genetic selection for A. galli resistance in chickens, which will be of importance for birds kept in alternative and organic farming systems.     

Ascaridia galli infections in free-range layers fed on diets with different protein contents

1. One hundred and twenty 17-week-old Lohman Brown hens were divided into 4 groups. Groups 1 and 3 were given a diet with 180 g protein/kg and groups 2 and 4 were given a diet with 140 g protein/kg. Groups 1 and 2 were orally infected with 500 (50) embryonated Ascaridia galli eggs. 2. Marked differences in mean weekly weight gain for the 4 groups were observed. 3. Hens given 140 g protein/kg had a significant lower mean worm burden of adult A. galli worms and a significant lower weight gain compared to the group given 18 g protein/kg. 4. There was no significant difference in faecal egg counts between the 2 parasitised groups. 5. The egg production did not differ significantly between any of the groups. 6. The results of this study indicate that the amount of dietary protein in the diet has an effect on the establishment of A. galli infections in the gut of layers kept under free range conditions.     

鹅蛔虫ITS rDNA的分子特征及种类分析

为探究从广东省清远的鹅体内采集的蛔虫(Ascaridia anseris)的种类,对临床采集的鹅蛔虫样品,在形态观察的基础上,用保守引物NC5和NC2扩增鹅蛔虫的ITS rDNA基因片段,将扩增产物经克隆测序后,获得大小为1 009bp的鹅蛔虫ITS rDNA基因序列(GenBank登录号为KC905082)。序列比对和系统进化分析表明,鹅蛔虫5.8SrRNA基因与GenBank收录的鸡蛔虫(登录号为AJ001508)同源性为96%,而与不同地理株的鸽蛔虫的同源性在91%~96%之间;禽蛔科的鸡蛔虫、鸽蛔虫和鹅蛔虫同一进化分支,鹅蛔虫、鸡蛔虫和鸽蛔虫处于各自的独立进化分支。上述证明,鹅蛔虫是不同于鸽蛔虫的一个独立有效种,在系统发生关系上与鸡蛔虫更亲近。     

湖南鸡隐孢子虫感染情况调查及雏鸡人工感染试验

作者对湖南省５县（市）８个鸡场的３４８只鸡进行了隐孢子虫感染的调查，并用２５只雏鸡作了隐孢子虫的人工感染试验。调查表明：４个县（市）有鸡隐孢子虫感染，感染率为２．８～２５．０％，总感染率为１２．１％，其中２～４周龄鸡为３．６％，８～４０周龄鸡为１５．１％，伊莎鸡、ＡＡ鸡、罗曼鸡、艾维茵鸡、泰国肉鸡分别为２１．９％、１３．６％、９．１％、５．４％和０；１０只阳性鸡器官粘膜涂片检查盲肠、法氏囊、直肠的染虫率分别为１００％、６０％和４０％，气管、十二指肠和小肠中段未查到虫体。雏鸡人工感染试验表明：经鼻腔和眼结膜感染潜隐期均为５天；经口感染潜隐期为４天，第８～１９天排出卵囊数较多，第１２天排卵囊达到最高峰，显露期为２１天。