The influence of stocking density on behaviour, health, and production in commercial fattening turkeys - a review.

1. This paper reviews literature on the effects of stocking density on behaviour, health, and production in intensively housed fattening turkeys.2. Worldwide, there are various regulations and recommendations on the maximum stocking density. While stocking density can be determined based on the space covered by the body, a more appropriate method considers space requirements for natural behaviour. Turkeys are less likely disturbed at low stocking density as seen by increased sitting, lying, and preening behaviours compared to animals housed at high stocking density. Furthermore, lower stocking density together with smaller group size, species-appropriate light conditions and suitable structuring of barn housing are repeatedly mentioned as good strategies to prevent injurious pecking.3. Increased stocking density - in terms of weight and animal number per floor area - is related to increased litter moisture, which can have negative impact on animal health. High stocking density can also lead to poor body mass gain and increased mortality, which are not only indicators of impaired welfare but also of economic interest.4. Based on the available scientific literature and economic aspects with regard to the above criteria, a maximum stocking density for turkeys appears to be 36-a maximum of 40 kg live weight per m2 of usable floor space. However, the number of animals per square space should also be limited to avoid increased litter moisture and reduced health.

Aerobic cloacal and pharyngeal bacterial flora in six species of free-living birds.

AIMS: The purpose of this study was to investigate the culturable aerobic pharyngeal and cloacal bacterial flora of free-living birds, to determine the physiological bacterial microbiota, to identify possible interactions between feeding behaviour and the composition of the pharyngeal and cloacal microflora and to investigate the occurrence of pathogenic bacteria. METHODS AND RESULTS: Cloacal and pharyngeal swabs of 167 free-living birds, including water rails (Rallus aquaticus), spotted crakes (Porzana porzana), mute swans (Cygnus olor), barn swallows (Hirundo rustica), reed warblers (Acrocephalus scirpaceus) and black cormorants (Phalacrocorax carbo) from Germany, were cultured to determine the prevalence of aerobic bacteria. Statistical analysis of bacterial findings and feeding behaviour was performed. A widespread soil and water bacteria were isolated, which are expected to be present in the habitat and food. However, some potentially avian- and human-pathogenic bacteria, such as Aeromonas hydrophila, Elizabethkingia meningoseptica, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, were also recovered. CONCLUSIONS: Free-living birds of the examined species harbour several environmental bacteria, which could be facultative pathogenic. SIGNIFICANCE AND IMPACT OF THE STUDY: Prevalence of bacteria in healthy free-living birds of the species included in this survey is influenced by environmental and alimentary factors.

Prevalence and severity of foot pad alterations in German turkey poults during the early rearing phase.

In the previously performed field study from 2007 to 2009, it became evident that foot pad alterations were already commonly found in turkeys at the age of 6 wk. At this early age, 45% of the clinically examined birds were diagnosed with epithelial necrosis. Therefore, it became important to specifically analyze the situation during the early rearing phase. The present study reflects the prevalence and severity of foot pad alterations of turkey poults up to the age of 35 d (5 wk), starting as early as the age of 3 d. From 24 turkey farms throughout Germany, in general 5,531 turkeys [3,131 male and 2,400 female] of the British United Turkeys 6 strain from 46 flocks, were examined to that effect. Prevalence and severity increased within the duration of stay in the stable, and the prevalence was higher (P < 0.001) during the second visit between d 22 to 35 (factor: 0.94). Therefore, 27.3% (d 3 to 5; male/female: 39.1/25.0%) and 63.3% (d 22 to 35: 61.3/65.7%) of the examined poults had alterations of the foot pads, such as hyperkeratosis (d 3 to 5: 20.4/14.2%; d 22 to 35: 17.6/17.1%), high-grade hyperkeratosis with adhesive dirt (d 3 to 5: 8.7/10.7%; d 22 to 35: 29.2/39.3%), and epithelial necrosis (d 3 to 5: 0.1/0.1%; d 22 to 35: 14.6/9.3%). Female poults showed a higher risk (P < 0.001) of developing food pad alterations (factor: 0.76) than male poults. Male poults developed a higher percentage of epithelial necrosis than hens shortly before relocation. A higher stocking density during the very early rearing phase (d 3 to 5) led to a worse foot pad health status (P < 0.001). Because even mild alterations in the foot pad condition can be indicators for suboptimal design of the rearing environment and are to be seen as a pre-state for severe cases of foot pad dermatitis, it is important to set the main focus on the early rearing phase.

Examinations on the prevalence of footpad lesions and breast skin lesions in British United Turkeys Big 6 fattening turkeys in Germany. Part I: prevalence of footpad lesions.

The present study demonstrates the prevalence of footpad lesions in turkeys and their level of expression in both live birds and in carcasses. In clinical investigations of 11,860 turkeys (5,740 males, 6,120 females) of the strain British United Turkeys Big 6, individuals of all the observed flocks showed alterations to the plantar skin. In general, the degree and severity of skin alterations were higher in the 16th week of life than in the 6th or 11th week of life. Epithelial necrosis, however, was already apparent in about 45% of individuals in the 6th week of life. At this point, deep lesions on the footpad surface were still rare findings. In the 11th week of life, such skin changes were apparent in 14.7% of males and 25.7% of hens. In general, the feet of male turkeys were less affected by footpad damage than those of females in the subsequent fattening period. In hens, the prevalence of lesions of the footpads at wk 16 of age was 60.0%, almost twice as high as in males of the same age group (33.8%). A comparison of the findings from the right and left feet showed that the state of the 2 extremities was correlated (Spearman correlation: r = 0.830). During the visual inspection of 16,200 slaughtered turkeys (7,800 males, 8,400 hens), almost all carcasses studied showed alterations to the footpad skin. Only 2.1% of males and 0.6% of females were without lesions. The most frequently observed lesions measured up to 2 cm in diameter (males: 59.2%; hens: 57.7%). Pronounced skin lesions of the footpad (males: 21.1%; females: 29.5%) and necrosis of the superficial epithelium (males: 17.5%; females: 12.1%) were less common. Foot abscesses were diagnosed only sporadically (males: 0.1%; females: 0.1%).

Examinations on the prevalence of footpad lesions and breast skin lesions in B.U.T. Big 6 fattening turkeys in Germany. Part II: Prevalence of breast skin lesions (breast buttons and breast blisters).

This project involves the prevalence of breast skin alterations (breast buttons, blisters, purulent bursitis) in male and female fattened turkeys (British United Turkeys Big 6) from conventional intensive farming. In this case, 24 turkey farms across Germany and 11,860 turkeys (5,740 toms, 6,120 hens) were clinically examined, and 16,200 birds (8,400 hens, 7,800 toms) were evaluated on slaughter lines at 7 turkey abattoirs. Each turkey farm included examination of at least 3 consecutive fattening cycles. Especially in the meat examinations, breast skin alterations were a frequent discovery, particularly in the form of breast buttons. The turkey toms exhibited a prevalence of 27.15%, and the toms were affected significantly more frequently (P < 0.001) by these variations than the turkey hens (7.77%). It is possible that the higher BW of the male specimens leads to increased lying times and is therefore connected with more severe strain on the breast region. The increased fattening period of the turkey toms (slaughtering at wk 21 to 22 of life) vs. the female specimens (slaughtering at wk 15 to 17 of life) must be discussed as a cause. Breast blisters and bursitis sternalis were discovered with a prevalence of 7.36 and 1.24% in toms and more seldom in hens, at 0.30% and 0.15%. Large differences in prevalence were partially recognizable between individual farms as well as between the 3 fattening cycles on a farm. Breast buttons and breast blisters are pathological skin variations for which the etiology is multifactorial. Clear correlations between the prevalence of breast skin alterations and the manner of rearing the birds were not able to be determined. An improvement in this situation, which is considered very problematic from the perspective of bird protection and economics, may be achieved only via cooperation to achieve optimized rearing methods, management, and breeding practices.

[Endocrinologic studies of male psittacine birds for the evaluation of their reproductive status]. / Endokrinologische Untersuchung männlicher Papageienvögel zur Beurteilung ihres Reproduktionsstatus.

OBJECTIVE: Evaluating methods of hormone measurement in different specimens of male parrots in order to assess their reproductive status and stress axis. MATERIAL AND METHODS: Cockatiels and rose-ringed parakeets were chosen as psittaciforme representatives and their endocrine profiles were examined. In various pre-experiments, suitable techniques for the determination of testosterone in plasma, saliva and faeces of male parrots were established. Before analysing the samples by enzyme immunoassay, blood and faeces were extracted using diethyl ether, while saliva could be tested without extraction. Based on the excretion of mainly conjugated testosterone metabolites, parrots' faecal samples were also hydrolysed with ß-glucuronidase/arylsulfatase before extraction. In addition, the levels of the stress hormone corticosterone were determined by radioimmunoassay in order to assess possible relationships between stress and the secretion of testosterone. RESULTS: The examined psittacine species displayed different seasonal secretion patterns for both testosterone and corticosterone. Cockatiels had maximum plasma testosterone levels in February, in contrast, rose-ringed parakeets showed highest concentrations in November. As a consequence of cumulative excretion, both species showed much higher faecal than plasma testosterone concentrations. In rose-ringed parakeets, the levels of corticosterone in plasma were exceptionally high compared to the cockatiels. CONCLUSION: According to this study, we have been able to establish suitable methods for testosterone analysis in blood and faeces of cockatiels and rose-ringed parakeets, supporting the assessment of their reproductive status. At present saliva does not appear to be an ideal medium for reliable hormone level measurement, thus further investigations are required concerning this subject. CLINICAL RELEVANCE: By means of process analysis, it will be possible to detect increasing testosterone levels and/or pathological alterations, which could be considered in breeding programmes.

Spermatozoa characteristics in six psittacine species using light microscopy.

Even though breeding of companion birds has increased continuously for years, the fecundity assessment of birds has hardly been acknowledged. Knowledge of the structure of spermatozoa is crucial for evaluation of the basic reproductive biology of any species as well as for phylogenetic research and cladistic analyses of internal relationships. Spermatozoa of six different psittacine species (Nymphicus hollandicus, Myiopsitta monachus, Agapornis roseicollis, Melopsittacus undulatus, Tanygnathus lucionensis, Guarouba guarouba) were examined using light microscopy. Head length (nucleus including acrosome), head width, midpiece length and tail length were measured and documented. Significant differences were obvious among almost all of the species for almost all four parameters. However, in all the six species a significant moderate correlation between spermatozoa midpiece lengths and tail lengths (r=0.535, p

Investigation of the prevalence and severity of foot pad dermatitis at the slaughterhouse in fattening turkeys reared in organic production systems in Germany.

The present study shows the prevalence and severity of foot pad dermatitis (FPD) in turkeys reared in organic production systems assessed at slaughterhouses in Germany. The investigations of altogether 1,860 turkeys of the strains Kelly Broad Breasted Bronze (Kelly BBB; 540 toms, 540 hens) and British United Turkeys (B.U.T.) 6 and the Test Product 7 (TP 7; 780 hens) showed that 97.7% of the examined turkeys were diagnosed with different degrees of FPD. Only 4.6% of the toms and 1.3% of the hens had feet without lesions. Most frequent were necrotic lesions measuring up to 2 cm in diameter (64.3% of all turkeys). Extensive necrotic lesions of the foot pads (toms: 29.8%; hens: 12.4%) and necrosis of superficial scales (toms: 11.3%; hens: 7.6%) were less frequent. Plantar abscesses were rare findings (1.9%). In general, the feet of the Kelly BBB hens were more affected by foot pad lesions than those of the Kelly BBB toms. There were significant differences between the investigated flocks concerning the occurrence of foot pad lesions. The aim in rearing turkeys must be the reduction of FPD.

Computed tomography for the diagnosis and treatment monitoring of bacterial pneumonia in Indian pythons (Python molurus).

Eight Indian pythons (Python molurus) with clinical and microbiological evidence of pneumonia were examined by computed tomography (ct) before and after treatment. The results were assessed subjectively and measurements were taken following a standard protocol. Changes in the lung tissue of all the pythons were diagnosed, and the extent of the disease could be assessed. ct examinations after treatment showed an improvement in the six pythons whose clinical condition had improved, but in the other two pythons they demonstrated the severity of the disease. The subjective assessments were superior to the evaluation of measurements of attenuation in regions of interest. However, the average and the maximum attenuation provided additional information on the extent of the disease. Except for one python with only mild clinical signs, the attenuation after successful treatment was still higher than in healthy pythons.

Blindness as a sign of proventricular dilatation disease in a grey parrot (Psittacus erithacus erithacus).

An approximately eight-year-old female grey parrot (Psittacus erithacus erithacus) was presented with a two months history of blindness. The radiographic examination showed a dilatation of the proventriculus, ventriculus and gut. Ophthalmoscopy and electroretinography revealed degeneration of the retina. A proventricular dilatation disease was suspected. The bird was euthanased because of deteriorating condition and poor prognosis. The pathological examination showed an atrophy of the ventricular muscles and lymphoplasmacytic infiltrates of the myenteric plexus of the proventriculus, ventriculus and gut as well as moderate lymphoplasmacytic infiltrates of the cerebrum with moderate neuronophagia. Lymphoplasmacytic infiltrates in the retina, indicating proventricular dilatation disease, and subsequent retinal degeneration were found. A potential common aetiology for proventricular dilatation disease and blindness is discussed.

[3D-X-ray microcomputer tomography and optical coherence tomography as methods for the localization of the blastoderm in the newly laid unincubated chicken egg]. / 3D-Röntgen-Mikrocomputertomographie und Optische Kohärenztomographie als Methoden zur Lagebestimmung des Blastoderms im unbebrüteten Hühnerei.

The routine culling of the male offspring of hybrid layer type chickens is met with increasing public disapproval for both ethical and legal reasons. Until now practice-oriented methods for reliable sex diagnosis prior to hatch could not be developed. Molecular genetical analysis of blastodermic cells can be used for sex determination in unincubated eggs; however, knowledge of the precise localization of the germinal disc is crucial for the extraction of a carefully directed cell biopsy. In principle, 3D-X-ray micro computed tomography (3D-CT) has been proven a suitable method to localize the germinal disk in the unincubated egg without damaging the egg shell. No negative effects on embryogenesis and hatching rate of irradiated hatching eggs were established. The pictorial representation of the germinal disk using optical coherence tomography (OCT) failed in the unopened egg. The egg shell formed an impenetrable barrier for the currently available measuring method which utilized near infrared (NIR) wavelength regions. After opening the egg shell, the germinal disk could be visualized without any difficulties. In conclusion, technical possibilities for localization of the germinal disk in the unincubated egg already exist, but regarding technical parameters, the procedures have to be adapted to the specific purpose.

Current approaches to avoid the culling of day-old male chicks in the layer industry, with special reference to spectroscopic methods.

The negative correlation between fattening and laying performance prevents breeding improvement in both laying performance and meat yield. Therefore, specialized chicken lines have been bred in order to achieve either an efficient production of high-quality eggs or high growth rates. As a result, day-old male chicks are culled in the layer hatchery, which poses animal welfare and ethical problems. Breeding companies, scientific groups, and hatcheries are attempting to resolve this issue, with a common aim to find feasible alternatives for the routine killing of male layer chicks. Some approaches aim to influence the sex ratio, while others target at the economically feasible use of the male layer offspring, such as the fattening of "laying hen brothers" or crossbreedings of layers and broilers to create "dual-purpose chickens." Another approach is the sex determination prior to hatch. One of the prerequisites of in ovo sex determination is a practicable method that can be used in industry. The analysis needs to be rapid, cost-efficient, and highly precise; in addition, negative impacts on hatching rate, animal health, and/or performance parameters should be limited. Furthermore, sex determination should be performed before the sensory nervous system's response of the chick embryo to certain or potentially harmful stimuli is developed, which according to current knowledge is before the d 7 of incubation.

Vitamin A requirements of alipochromatic ('recessive-white') and coloured canaries (Serinus canaria) during the breeding season.

Six pairs of alipochromatic ('recessive-white') canaries (Serinus canaria) and six pairs of coloured canaries were kept through a complete breeding cycle while being fed a diet providing 12,000 iu vitamin A/kg. The eggs of three pairs (one recessive-white and two coloured) were all unfertilised and there were only 23 hatchlings (14 recessive-white and nine coloured), of which 14 (10 recessive-white and four coloured) were alive after the first moult. However, there was no clinical, biochemical or pathological evidence that the recessive-white canaries were suffering from vitamin A deficiency or that the coloured canaries were suffering from vitamin A toxicity, suggesting that the diet met the vitamin A requirements of both groups.

Plasma concentrations of voriconazole in falcons.

Doses of 12.5 mg voriconazole/kg bodyweight administered every 12 hours by crop gavage to six falcons for 14 days provided peak plasma concentrations of more than 1 microg/ml, but the trough concentrations were lower and sometimes undetectable. Administering the same doses incorporated into meat that was fed to one falcon for seven days and to three falcons for up to 91 days provided similar plasma concentrations.

[Significance of the sampling points and the aerobic microbiological culture for the diagnosis of respiratory infections in reptiles]. / Untersuchung zur Bedeutung der Probenschen Kultivierung zur Diagnostik von Infek-tionen des Respirationstraktes bei Reptilien.

Respiratory diseases play an important role in reptiles kept in captivity. Microbiological examinations are described as an essential part of the diagnostic possibilities. Therefore the aim of this study was to collect data on the usefulness of results obtained after aerobic culture (sheepblood, brilliantgreen, sabouraud's agar) of swabs and tracheal lavages following standardized sampling. Respiratory symptoms were found in 24.3% of the snakes, 16.5% of the tortoises/turtles and 1.6% of the lizards presented in the clinic for birds and reptiles at the university Leipzig. Altogether, 52% of the examined samples were found to be bacteriologically and 31% mycologically of pathologic significance. The tracheal lavage proved to be more sensitive in comparison to swabs taken from the pharynx. The bacteria most often found in the samples were Pseudomonas aeruginosa, Klebsiella pneumoniae and Stenotrophomonas maltophila. Mycologic culture revealed Aspergillus sp. and yeast most often. In boids and pythons, the highest number of bacteriologic results assessed to be of pathological significance were found (75%). Mycologically, samples from tortoises were found most often to have a result of pathological significance (48%). To summarize the aerobic cultivation on standard media (in this study: Columbia-Agar with sheep blood, brilliant-green-, Sabouraud-Agar) can be recommended as an initial diagnostic measure in reptiles presented with respiratory symptoms; further pathogens (eg, viral examination, Mycoplasma) should be checked additionally.

[Investigations on the influence of selected compulsory measures on clinically relevant haematological and blood-chemical parameters of racing pigeons (Columba livia f. dom.)]. / Untersuchungen zum Einfluss ausgewählter Zwangsmassnahmen auf hämatologische und blutchemische Parameter von Brieftauben (Columba livia f. dom.).

In the presented study the influence of stress and environmental factors on selected haematological and blood-chemical parameters in racing pigeons was examined. Blood was taken at three defined days and haematological as well as blood-chemical parameters of clinical relevance were determined. In comparison to reference values published for pigeons, the majority of the values obtained in this study were within physiological borders. The daily handling of the pigeons did not have any significant effect on the examined parameters. Also the heterophile/lymphocyte ratio did not show any changes characteristic of a stress reaction. In contrast, after change of the housing dies with pigeons originating normally from a flock, the first blood sampling should be performed after a 4 or 5-day lasting period of acclimatisation to the the individual housing conditions.

[Pilot study of echocardiographic studies using color- and pulsed-wave spectral Doppler methods in blue-crowned amazons (Amazona ventralis) and blue-fronted amazons (Amazona a. aestiva)]. / Pilotstudie zu echokardiographischen Untersuchungen mittels Farb- und pulsed-wave-Spektraldoppler an Blaukronenamazonen (Amazona ventralis) und Blaustirnamazonen (Amazona a. aestiva).

Colour-flow and pulsed-wave spectral Doppler echocardiography was performed on 6 healthy, adult Hispaniolan amazon parrots (Amazona ventralis) and 6 blue-fronted amazon parrots (Amazona a. aestiva) to establish normal reference values. Birds were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. An electrocardiogram was recorded continuously and birds were imaged with a micro-phased-array scanner with a frequency of 7.0 MHz. After assessment of cardiac function in 2-D-echocardiography, blood flow across the left and the right atrioventricular valve and across the aortic valve was determined using color-flow and pulsed-wave spectral Doppler echocardiography. Diastolic inflow (mean value +/- standard deviation) into the left ventricle was 0.17 +/- 0.02 m/s (Hispaniolan amazons) and 0.18 +/- 0.03 m/s (Blue fronted amazons). Diastolic inflow into the right ventricle was 0.22 +/- 0.05 m/s (Hispaniolan amazons) and 0.22 +/- 0.04 m/s (Blue fronted amazons). Velocity across the aortic valve was 0.84 +/- 0.07 m/s (Hispaniolan amazons) and 0.83 +/- 0.08 m/s (Blue fronted amazons). Systolic pulmonary flow could not be detected in any of the birds in this study. No significant differences were evident between the two species examined. Results of this study indicate that Doppler echocardiography is a promising technique to determine blood flow in the avian heart. Further studies in other avian species are needed to establish reference values for assessment of cardiac function in diseased birds.

The use of conventional radiography and computer-assisted tomography as instruments for demonstration of gross pathological lesions in the cranium and cerebrum in the crested breed of the domestic duck (Anas platyrhynchos f.dom.).

According to literature reports, the crested breed of the domestic duck (Anas platyrhynchos f. dom.) is described as a variety with high pre- and post-natal mortalities, malformations in skull and brain anatomy, and various central nervous deficiencies in affected birds. A detailed examination as to the cause and pathogenesis of these neurologic disorders has not yet been conducted, nor has an explanation concerning the inheritance of the feather crest been found. By using two non-invasive radiographic techniques, conventional radiography and computer-assisted tomography, living ducks were examined. Our studies have demonstrated that brain and skull anatomy of ducks of various breeds (Crested, Abacot Ranger, and German Pekin) can be well visualized using computer-assisted tomography. The Crested ducks investigated in this study showed abnormal fatty tissue deposits in the tentorium cerebelli, cranial malformations, and variable bone formations in the thickened hypodermis of the crest. In comparison with computer-assisted tomography, only parts of the skull changes were detected with conventional radiography; in no case could fat bodies be seen with this imaging method. An increase of the cranial capacity in the Crested ducks compared with other breeds examined (Abacot Ranger, German Pekin ducks) was found in morphometric studies carried out by computerassisted tomography. This increase of cranial capacity in Crested ducks results from an increase of the tentorial fatty depot during craniogenesis, as an enlargement of the fat body can influence cranium growth as long as the cranial bones are not yet fused. Thus, in comparison with other phenotypically similar domesticated birds like the crested chicken, the expression of the feather crest in domestic ducks demonstrates symptomatologic differences.

Morphometry of the heart of budgerigars (Melopsittacus undulatus), Alisterus parrots (Alisterus s scapularis) and common buzzards (Buteo buteo).

In order to establish data and reference values for the thickness of the myocardium and the length of the left and the right ventricle of the avian heart, the hearts of 14 budgerigars (Melopsittacus undulatus), five Alisterus parrots (Alisterus s scapularis) (also known as Australian king parrot) and 10 common buzzards (Buteo buteo) of both sexes were examined according to a standard protocol. In order to compare the results of birds of different sizes all data were related to the size of the bird's body (length of the sternum) and the results of the measurements of the myocardial thickness in relation to the length of the heart. Results of different zones were compared by means of statistical methods within one species. Besides that a comparison between the different species was performed. Only minor significant differences were noted.

Effect of handling-induced stress on the results of spectral Doppler echocardiography in falcons.

In order to evaluate the effects of habituation to handling on the Doppler-derived velocity of diastolic ventricular inflow and systolic aortic outflow, falcons that were accustomed to regular handling were compared with falcons that had been handled very little. The mean heart rate of the frequently handled birds was 111 beats per minute less than the non-habituated birds. All the mean blood flow velocities recorded were much higher in the non-habituated birds than those accustomed to handling. Taking into account the difficulty of objectively quantifying the level of stress suffered by any individual bird, the question is, if meaningful clinical or reference values for Doppler-derived blood flow velocities may be obtained in unsedated or non-anaesthetized birds?