Influence of Ascaridia galli infections and anthelmintic treatments on the behaviour and social ranks of laying hens (Gallus gallus domesticus)

In the present study, the effects of an experimental Ascaridia galli infection and anthelmintic treatment on the behaviour and social status of laying hens of two different lines were studied. Sixty white (Lohmann LSL; LSL) and 60 brown (Lohmann Brown; LB) hens were reared under helminth-free conditions. The hens of each line were divided into four groups. The birds in two of the groups were artificially infected with 250 embryonated A. galli eggs at an age of 27 weeks. The other two groups were kept as uninfected controls. One infection and control group was dewormed at 38 weeks of age and slaughtered 4 weeks later, contemporary with the other animals. Individual faecal Ascaridia egg counts (FEC) were performed 11 weeks post-infection (p.i.). Body weights, laying performance and egg weights were recorded regularly. Blood was taken to measure testosterone levels. The worm burdens established in the intestines were counted in the infected not treated group after slaughtering. In addition, 15 behavioural parameters were recorded by focal animal observation (n=10 per group) of one infection (plus anthelmintic treatment) and one control group, according to the time-sampling method throughout the experiment. All agonistic interactions within the groups were recorded simultaneously on an ongoing basis, thereby allowing the calculation of an individual social rank index. The following results were obtained: Mean FEC and worm burden were higher (p < 0.01) in the LSL hens than in the LB hens, but their performances were not different (p > 0.05) from the controls. Infections with A. galli resulted in significant behavioural changes in both lines as the infected birds showed a higher food intake and lower locomotion activity during the prepatent and patent periods. After anthelmintic treatment, food intake decreased and locomotion increased. Behavioural changes were more pervasive in the infected LSL hens, as these hens also showed changes in ground pecking and nesting activity not only during the prepatent and patent periods, but also after anthelmintic treatment. Social rank did not significantly change as a consequence of A. galli infection, but the infection groups of both lines had a tendency to display more agonistic activity than the non-infected controls. Serum testosterone values only increased significantly in the LSL hens during the patent period compared to the controls. No significant correlations were apparent between serum testosterone level, parasitic parameters, social status and/or aggressiveness in any of the groups. This study showed that even sub-clinical A. galli infections and their anthelmintic treatment can have an impact on animal behaviour.     

Infection dynamics of Ascaridia galli in non-caged laying hens

The infection dynamics of Ascaridia galli in laying hens was investigated in six commercial non-caged flocks. Three flocks were managed in accordance with the regulations for organic production and had outdoor access, whereas three flocks were housed indoors in aviaries or traditional floor systems. Faecal egg counts and total worm burdens were determined at specified intervals during the first 50 weeks of the production period. In two conventional flocks the efficacy of flubendazole on lumenal stages was investigated. All flocks became infected following the arrival of the birds (post placement) with residual infective eggs derived from the previous flock. In four flocks (two organic and two conventional) parasite eggs were first detected in faeces 6-7 weeks post placement, whereas parasite eggs were not detected until after 17-18 weeks in two flocks. This delay was observed in two of three flocks that were housed in barns that had been thoroughly cleaned and disinfected by chlorocresol. In three flocks (two conventional and one organic) flubendazole was administered to the birds in the drinking water for approximately one week. Both conventional flocks were dewormed twice approximately 20 weeks apart, whereas the organic flock was dewormed only once about 40 weeks post placement. Parasite eggs reappeared after deworming in all flocks, often within 2-4 weeks, followed by a rapid increase in parasite egg expulsion. Our results suggested impairment of host immunity post treatment, as the egg counts exceeded pre-treatment levels after 7-8 weeks on both conventional farms. Accordingly, the way by which anthelmintics and/or disinfectants are used in non-caged chicken flocks must be refined.     

Bilateral apex pubis distance：a novel index for follicular development and egg laying status in domestic hens (Gallus gallus domesticus)

ABSTRACT

1. Measures of the bilateral apex pubis (BAP) in White Leghorn (WLH) hens aged from 16 to 64 weeks (from the time ovaries were completely undeveloped to senility) were ranked into various groups so the relationship between external traits (BAP distance, comb length, comb height, wattle length, wattle height, body weight) and internal traits (largest ovarian follicle diameter (LFD) and oviduct weight and length) could be determined.

2. Using correlation and regression analysis with data from 16 weeks of age to the onset of lay, measurements of the apex pubis showed a strong correlation with LFD (r = 0.80, P < 0.01) and oviduct weight (r = 0.80, P < 0.01).

3. Multiple comparisons among WLH hens from 16 to 43 weeks of age showed that the BAP distance increased in all groups ranked by LFD or by laying period.

4. In the late laying period (>60 weeks of age), BAP distance showed a significant decrease (P < 0.01) in long-term non-laying hens compared to laying hens.

5. These findings suggest BAP distance can serve as an index for evaluating the onset and probable stages of follicular development during sexual maturation and/or aid in the identification and selection of non-laying hens during reproduction.     

Multiple perineuriomas in chicken (Gallus gallus domesticus)

Intraneural perineurioma is an extremely rare condition characterized by perineurial cell proliferation within peripheral nerve (PN) sheaths. In the veterinary field, this entity has been reported only in a dog. We examined multiple enlargements of PNs in 11 chickens (Gallus gallus domesticus) (9 Japanese bantams and 2 specific pathogen-free White Leghorn), which were inoculated with an avian leukosis virus (ALV) causing so-called fowl glioma. All chickens clinically exhibited progressive leg paralysis. Lumbosacral plexus, brachial plexus, and/or spinal ganglion were commonly affected, and these nerves contained a diffuse proliferation of spindle cells arranged concentrically in characteristic onion bulb-like structures surrounded by residual axons and myelin sheaths. The spindle cells were immunohistochemically negative for S-100alpha/beta protein. Electron microscopy revealed that these cells were characterized by short bipolar cytoplasmic processes, occasional cytoplasmic pinocytotic vesicles, and discontinuous basal laminae. These features are consistent with those of intraneural perineurioma. Furthermore, the specific sequence of the ALV was detected in the PN lesions of 8/11 (73%) birds by polymerase chain reaction. These results indicate that the multiple intraneural perineuriomas of chicken may be associated with the ALV-A causing fowl glioma.     

Effect of permethrin impregnated plastic strips on Dermanyssus gallinae in loose-housing systems for laying hens.

The effect of permethrin impregnated plastic strips (Die No Mite Strips) was evaluated on Dermanyssus gallinae populations in aviary systems for layers in Sweden. Two application strategies of the strips were tested: (A) attached in the housing system, allowing the birds to rub against the strips and thereby get the acaricide released onto their plumage, and (B) attached out of reach of the hens, at two different sites (perches and egg-belt lids) of the inner surfaces of the system, where the mites sheltered during the day. On two farms with 2030 (A) and 3384 (B) hens, and existing mite populations, strips were mounted for 20 and 10 weeks, respectively, and mite numbers were monitored by traps. With application A an overall mite reduction of 53% was observed, while with B the mean mite numbers decreased by 39% at the perches and 92% at the egg-belt lid. The strips were originally designed for caged hens afflicted by ectoparasites that stay on the host for most of their life cycle. However, since D. gallinae spends most of its time off the host, it was not possible to control the parasite with application A. Resistance tests performed on mites from both treated and control compartments where application A was used showed no indication of resistance to permethrin, while 95% of the mites survived a 48 h exposure to the compound where application B was performed. Thus, permethrin resistant mites appeared to be the main reason for the failure to control D. gallinae with application B.     

Let me sleep! Welfare of broilers (Gallus gallus domesticus) with disrupted resting behaviour

Perching is important for broiler welfare, however, hampered by body weight. In a mixed flock, resting behaviour and location were compared between three broiler hybrids (Rowan Ranger, Hubbard CYJA57 &; Ross 308; n?=?100/hybrid), differing in growth. Rearing was in a large littered pen (1.84 birds/m²), with perches. Behaviour and position was observed in focal birds on daytime and as group scans on daytime (days 11, 45, 61 and 80) and night-time (days 63, 70 and 77). Birds were slaughtered at 84 days and accumulated mortality in fast-growing birds was 20% and 2% in slow-growing. Resting frequency did not differ though fast-growing broilers perched less and lower, at night (P?P?P?相似文献   

Metastatic melanomas in young broiler chickens (Gallus gallus domesticus)

Four young broiler chickens affected by multiple melanotic tumors are described. Grossly, there were multiple tumors composed of melanocytes within the skin, skeletal muscle, and multiple visceral organs. Tumors ranged from flattened macules to masses that extensively replaced viscera. Microscopically, melanocytes were often well pigmented, and while there was moderate nuclear anisokaryosis, mitotic rates were low. Immunohistochemical staining of some melanomas with antibodies to S100 proteins, Melan-A, vimentin, or neuron-specific enolase after bleaching of tumor cells with potassium permanganate revealed lack of immunostaining of tumor cells with antibodies to S100, strong positive staining of tumor cells for neuron-specific enolase, moderate staining with antibodies to vimentin, and faint staining for Melan-A. Only neuron-specific enolase staining was evident in unbleached tumor cells. Attempts to identify exogenous avian leukosis viruses in these tumors were unsuccessful.     

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.     

Influence of light and darkness on the behaviour of Dermanyssus gallinae on layer farms

The behaviour of Dermanyssus gallinae was investigated on two layer farms where two different light programs were introduced in the 40th week of hen life. In layer house No. 1, light was applied continuously for 16 hours during the day, while layer house No. 2 was subjected to 4 hours of light and 2 hours of darkness applied alternately during the day. To monitor the level of red mite infestation, 30 tube traps were placed in every layer house corridor at a height of 1.5 m above the floor. In the first layer house, 280 Dermanyssus gallinae females, 50 nymph larvae and 198 eggs were found in 100 mg of tube trap material during 16 hours of the light phase, while during the 8-hour darkness phase, 1240 females, 70 nymph larvae and 110 eggs were collected. In the other layer house (with an alternating light phase of 4 hours and a darkness phase of 2 hours per day), 387 Dermanyssus gallinae females, 401 nymph larvae and 1060 eggs were found in trap tubes over the 8-hour dark phase, while 343 females, 202 nymph larvae and 1106 eggs were discovered over the 16-hour light phase.     

Ontogeny of brain temperature regulation in chicks (Gallus gallus domesticus)

1. Development of brain temperature regulation was studied in the domestic fowl (Gallus gallus domesticus) from hatching to 21 d of age. 2. Body and brain temperature at hatching were relatively low compared with adult levels. However, both were effectively regulated at ambient temperatures of 30 and 35 degrees C, with only a minor difference between the 2 temperatures. 3. Body and brain temperature increased as a power function of age at significantly different rates, approaching adult levels at around 10 d of age and resulting in a linear increase in body-to-brain temperature difference with age. 4. The results indicated the existence of different patterns of post-hatching development of brain temperature regulation in relation to the degree of precocity of a species.     

Changes in luteinizing hormone-containing gonadotrophs after moulting induced by fasting and zinc in laying hens (Gallus domesticus)

The purpose of the present study was to investigate egg production performance, immunohistochemical (IHC) identification, localization and morphological characterization of moulted hen’s pars distalis luteinizing hormone (LH) gonadotrophs. This system has been validated for chicken LH by immunodetection of purified hormones on dot blots, western blotting and by specific labelling of cells on sagittal sections of chicken pituitaries. This study showed that egg production and egg weight increased significantly after zinc-induced moult when compared with fasting-induced moult. Luteinizing hormone-gonadotrophs are of numerous shapes and distributed throughout the adenohypophysis, with densely populated regions on the margins of pars distalis. Moulting of laying hens was associated with a significant increase in immunoreactive LH gonadotroph cell count and cell size, which peaked at the subsequent production stages. Zinc-induced moulting also caused a significant increase in LH gonadotroph cell size as compared with fasting-induced moulting. The nuclear size of LH-positive cells was distinct during decreased egg production. Our results validate the use of ovine LHβ antibodies for the IHC localization of chicken LH gonadotrophs. This technology was further applied to the characterization of the shape and morphological changes of gonadotrophs as a function of the egg production status of the birds.     

Field efficacy of phoxim 50% (ByeMite) against the poultry red mite Dermanyssus gallinae in battery cages stocked with laying hens

Infestations with the poultry red mite Dermanyssus gallinae represent a major ectoparasite problem in poultry and can affect egg layers worldwide. There is presently a lack of an ectoparasiticide in Europe for poultry which can assure a 0-day withholding period for eggs. In this study, ByeMite (phoxim 50%, Bayer HealthCare, Animal Health Division) was administered to treat a D. gallinae infestation in a poultry house stocked with egg-laying hens kept in a cage system. A layer house was sprayed twice within a 7-day interval using a solution containing 2000 ppm phoxim and a similar layer house was used as an untreated control unit. Specially developed D. gallinae traps made of cardboard were used to assess the mite density in both layer houses during a 49-day period after the treatment. In order to collect mites, the traps were placed on days--1, 2, 6, 9, 13, 20, 34 and 48 and always removed after 24 h. The collected mites were counted and differentiated according to their developmental stage (mite eggs, larvae, nymphs, adults). Three days after the first spray treatment, the efficacy against all mite stages (larvae, nymphs, adults) was 96.1%, and from day 7 post-treatment until the end of the trial (day 49) the efficacy exceeded 99%. In contrast, in the untreated layer house (negative control group) the mite population showed a 400% increase. No treatment-related side effects in chickens were detectable. It is concluded that two administrations of ByeMite within a 7-day interval are highly effective against D. gallinae infestations in a stocked poultry house.     

鸡皮刺螨引起产蛋下降的诊断与治疗

2007年6月，邢台县某养鸡场所饲养的一批高峰期产蛋鸡群鸡因发病产蛋率持续下降，虽经多个兽医诊治均未出现好转，并开始出现鸡只伤亡，经笔者进行检查，确诊为由鸡皮刺螨引起的寄生虫性传染病。通过采取有效治疗办法，鸡群明显好转，15日后产蛋率恢复正常。现将诊断与治疗情况报告如下：     

The effect of levamisole and albendazole on some enzymes of Ascaridia galli and Heterakis gallinae

Ascaridia galli and Heterakis gallinae obtained from the common fowl Gallus gallus were exposed to 10(-2)-10(-5)M levamisole and albendazole; both compounds caused death of the parasites in vitro. The effect of the drugs was investigated on homogenates of the treated worms. Albendazole, at 10(-2)M, inhibited oxaloacetate reduction by 67 and 53% and malate oxidation by 21 and 17% in A. galli and H. gallinae, respectively, whereas 10(-4)M levamisole completely inhibited malate dehydrogenase activity in both directions in the two parasites. Lactate dehydrogenase was not affected significantly by either anthelmintic. Aldolase activity was diminished by 57 and 32% in A. galli and H. gallinae, respectively, with 10(-4)M levamisole. Levamisole at 10(-4)M also inhibited the activity of acid and alkaline phosphomonoesterase and cholinesterase. Albendazole had no significant effect on these enzymes in either parasite. Malate dehydrogenase and cholinesterase activity of the host tissue (intestine and caecum) was also reduced significantly with 10(-2) and 10(-3)M levamisole. These studies indicated a multiple mode of action of levamisole and albendazole.     

Uterine adenocarcinoma with transcoelomic metastases in breeder hens (Gallus domesticus)

Hens involved in a Newcastle disease study were euthanased at regular intervals according to a designed protocol. Of these, 7.14 % (n = 42) of the 82-week-old specific pathogen-free breeder hens were found to have well-delineated firm white to yellowish nodules of varying sizes in the abdominal cavity. Histologically, the nodules were identified as an adenocarcinoma originating in the uterus. Transcoelomic spread was evidenced by the presence of similar neoplastic cells embedded in the serosa and outer longitudinal muscle layer of the intestines as well as the liver.     

Experimental stimulation of eosinophil production in the domestic fowl (Gallus gallus domesticus)

A method has been devised to produce eosinophilia in birds experimentally. Multiple intraperitoneal injections of bovine serum albumin (BSA) produced a greater response than horse serum in young adult fowls, and injections of 2 ml BSA were more effective than injections of 0.2 ml. The highest eosinophilic responses were obtained with injections of BSA together with aluminium hydroxide. Thymectomy had little effect on eosinophil numbers following horse serum injections but irradiation produced a depressed response. Horse serum that had been heated to 56 degrees C for 30 minutes to inactivate complement and to denature proteins, including possible horse IgE, induced an eosinophilic response in 50 per cent of birds compared with only 14 per cent with unheated horse serum. Furthermore, when the former birds were reinjected after a rest period of 13 weeks, the eosinophilic response followed a similar curve as before but a higher proportion of birds responded. Birds aged over two years did not give a good eosinophilic response after horse serum stimulation. There was no consistent correlation between raised IgE levels and eosinophil numbers. Tolerance to horse serum was detected in some birds using a radial immunodiffusion technique. Analyses of blood plasma from birds with eosinophilia showed a significant increase in total amino acids compared with normal birds.