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PubMed1992

Stress measurements on beak-trimmed and untrimmed pullets.

Stress in poultry is difficult to define and measure. There is general agreement that some modern poultry production practices may exert a certain amount of stress on birds. Three experiments were conducted to explore possible measures of stress associated with beak trimming and rearing schemes. Experiments 1 and 2 examined different degrees of beak trimming and rearing schemes of wire floor versus litter floor in pullet production. Experiment 3 examined the effect of beak trimming on feed consumption for 14 days after trimming. Adrenal glands of untrimmed birds were heavier (P less than .05) than those of trimmed birds at the end of the pullet growing period in Experiments 1 and 2, evidence that beak trimming reduced overall chronic stress levels. Hearts of untrimmed birds were heavier (P less than .05) than those of trimmed birds in Experiment 1. Hearts and spleens were not affected in Experiment 2. In comparisons of rearing schemes (litter versus wire), birds grown on litter floors had heavier adrenal glands and a greater incidence of cannibalism in the later weeks of Experiments 1 and 2. This indicated that a stressful interaction among penmates had occurred. Birds grown on litter floors consumed more feed than those grown on wire, and the untrimmed birds from both floor types consumed more total feed than trimmed birds. By the end of the growing period, body weights were not different in either study, indicating compensation for any early beak trimming stress. Beak trimming produced a decrease in feed intake in Experiment 3, consumption was reduced (P less than .05) in 5 of the first 8 days after trimming.

Adrenal Glands↗
PubMed1979

Skull growth after partial prospective lower beak extirpation in chick embryos.

On one side of chick embryos in stage 28, part of the prospective lower beak or the entire prospective lower beak anterior to the buccal corner was removed surgically (CLB-A and CLB-B embryos, respectively). In another group the prospective lower beak was split in the midsagittal plane (CMS embryos). The controls were shame-operated embryos (CS). The skulls of stage 39 CLB-A and CLB-B embryos showed changes in the lower beak as well as in the skull base, the pterygoid, the quadrate, the palatine, and the upper beak. Stage 39 CMS embryos showed shortening of the dentary and Meckel's cartilage. At the tip of the CMS mandible, an excessive amount of osseous material was found. The results support Dullemeijer's (1974) views concerning the issue of dependency of functional components. The value of a combined developmental and functional approach to morphology, i.e., integrated investigation of development of structure and function of the beaks and related jaw musculature, is discussed.

Animals↗
PubMed1979

The influence of the lower beak on the interorbital septum-prenasal process complex in the chick embryo.

The effect of removal of the lower beak on the development of the interorbital septumprenasal process (ISPP) complex was studied in chick embryos. In normal development the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process increases. At the same time the angle between the ventral contour of the interorbital septum and the basal plate increases. After surgical removal of the prospective lower beak at stage 29, the position of the entire ISPP complex was altered in stage-38 embryos and the prenasal process showed elongation. In stage-38 embryos in which the prospective upper beak had been removed at stage 29, Meckel's cartilage was elongated. It is concluded that straightening of the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process is not influenced by the lower beak, whereas the position of the entire ISPP complex and the size of the prenasal process are under the epigenetic influence of the lower beak. The position and size of Meckel's cartilage are under the epigenetic influence of the upper beak.

Animals↗
PubMed1991

The effects of ion implantation on the beaks of orthodontic pliers.

The surface of stainless steel may be hardened by bombarding the material with a stream of nitrogen ions generated by a nuclear accelerator. In the present study this technique was used to determine the hardening effect of ion implantation on the beaks of stainless steel orthodontic pliers. Ten orthodontic pliers (Dentarum 003 094) were divided into two equal groups, designated control and experimental. The beaks of the experimental pliers were subjected to ion implantation, after which the tips of the beaks of all the pliers were stressed in an apparatus attached to an Instron testing machine. A cyclical load of 500 N was applied to the handles of the pliers, while a 0.9 mm (0.036 inch) round, stainless steel wire was held between the tips of the beaks. The effect of the stress was assessed by measurement with a traveling microscope of the gap produced between the tips of the beaks. Measurements were taken before loading and after 20, 40, 60, and 80 cycles. Statistical analysis of variance and the two-sample t tests indicated that there was a significant increase in the size of the gap as the pliers were stressed from 0 to 80 cycles (p less than 0.001). Furthermore, the mean gap was significantly greater in the control group than in the experimental group (p less than 0.001). This study suggests that ion implantation increases the hardness of the tips of the beaks of orthodontic pliers.

Analysis of Variance↗
PubMed2003

Bacterial sinusitis as a cause of beak deformity in an Antipodes Island parakeet (Cyanoramphus unicolor).

CASE HISTORY: From 26 days of age, an Antipodes Island parakeet (Cyanoramphus unicolor) was noted to have a severe beak deformity and reduced bodyweight gain compared to its nest mate. The bird was euthanised at 43 days of age. CLINICAL AND PATHOLOGICAL FINDINGS: The beak abnormality consisted of distortion of the right nares and severe shortening resulting in deviation of the upper maxilla to the right and cranially. On sectioning the head, copious mucoid material was found in the infraorbital sinus and the bony sinus architecture was disrupted. Histopathological examination of the infraorbital sinuses revealed a large focus of chronic but active inflammation, bony lysis on the right side and pockets of a mixed population of bacteria. DIAGNOSIS: Severe beak deformity, likely secondary to bacterial sinusitis. CLINICAL RELEVANCE: The case illustrates the need to look for underlying aetiologies to beak malformation, particularly in young parrots. KEYWORDS: Sinusitis, beak malformation, Antipodes Island parakeet, parrot, beak growth.

Journal Article↗
PubMed2004

Upper beak truncation in chicken embryos with the cleft primary palate mutation is due to an epithelial defect in the frontonasal mass.

In this study, we used the chicken mutant strain known as cleft primary palate (cpp) to study the mechanisms of beak outgrowth. cpp mutants have complete truncation of the upper beak with normal development of the lower beak. Based on structural analysis and grafts of facial prominences, we localized the defect to the frontonasal mass and its derivatives. Several explanations that would account for the outgrowth defect were investigated, including abnormal expression of genes in the frontonasal epithelium, intrinsic defects in epithelium and/or mesenchyme defects in epithelial-mesenchymal signalling, a localized decrease in cell proliferation or a localized increase in programmed cell death. One of the genes expressed in the frontonasal epithelial growth zone, Fgf8, failed to down-regulate and was maintained for at least 48 hr beyond the time when down-regulation normally occurs. Recombination experiments further illustrated that the frontonasal mass epithelium was abnormal in the cpp mutants, whereas mutant mesenchyme was capable of normal outgrowth when combined with wild-type epithelium. Cell proliferation was not decreased in mutant embryos nor was cell death initially increased. Later, at stages 31-32, when the prenasal cartilage begins directed outgrowth, there was an increase in cell death within the mutant upper but not lower beak cartilage. The cpp beak truncation, therefore, is due to an epithelial defect in the frontonasal mass that is coincident with a failure to down-regulate expression of Fgf8.

Animals↗
PubMed1993

Sensory nerve endings in the beak skin of Japanese quail.

This study is concerned with the distribution and ultrastructure of sensory nerve endings in the beak skin of adult Japanese quail (Coturnix coturnix japonica). The following nerve endings were found: free nerve endings, clusters of dermal Merkel nerve endings, Herbst corpuscles and Ruffini corpuscles. The latter were found only in the dermis of the tip of the upper beak. The remaining endings were present in the skin of all areas of upper and lower beak. Free nerve endings were supplied by either thin myelinated axons or unmyelinated C-fibers and were localized in the dermis close to the basal layer of the epidermis. Merkel cells formed clusters (up to 50) localized below and between the epidermal cones of the beak skin. Disc-shaped thickenings of nerve endings were squeezed between individual Merkel cells. Small Herbst corpuscles were found in the dermis close to the epidermal cones of the beak skin. Large Herbst corpuscles occurred in deep layers of the dermis. The Ruffini corpuscles were cylindrical in shape (80 microns x 400 microns) and arranged in groups of up to ten corpuscles. Each corpuscle was surrounded by an incomplete fibrous capsule.

Animals↗
PubMed1976

The proteins of the keratin component of bird's beaks.

Birds' beaks have an outer shell of hard keratin which consists almost entirely of proteins which are very rich in glycine [about 30 residues per 100 residues (residues %)], contain moderate levels of tyrosine and serine (each about 8 residues %), and which have relatively low contents of cystine (about 2-5 residues %), lysine, histidine, isoleucine and methionine. Major protein fractions in the S-carboxymethyl form isolated from the beaks of six different orders of birds have similar amino acid compositions, isoelectric points (pH 4-2-4-9) and molecular weights (13,000-14,500). Detailed chromatographic electrophoretic and compositional studies of the proteins of kookaburra beak reveal them to be a family of closely related proteins with only limited heterogeneity, in contrast to mammalian keratin systems. The major kookaburra beak fraction is similar in overall composition and molecular weight to fowl epidermal scale, kookaburra claw and turtle scute proteins and shows some resemblance to reptile claw protein. Beaks also contain small amounts of protein which are distinctly different from the major fraction but which resemble feather keratin proteins in composition and size.

Amino Acids↗
PubMed2005

Ultraviolet reflecting photonic microstructures in the King Penguin beak.

King and emperor penguins (Aptenodytes patagonicus and Aptenodytes forsteri) are the only species of marine birds so far known to reflect ultraviolet (UV) light from their beaks. Unlike humans, most birds perceive UV light and several species communicate using the near UV spectrum. Indeed, UV reflectance in addition to the colour of songbird feathers has been recognized as an important signal when choosing a mate. The king penguin is endowed with several highly coloured ornaments, notably its beak horn and breast and auricular plumage, but only its beak reflects UV, a property considered to influence its sexual attraction. Because no avian UV-reflecting pigments have yet been identified, the origin of such reflections is probably structural. In an attempt to identify the structures that give rise to UV reflectance, we combined reflectance spectrophotometry and morphological analysis by both light and electron microscopy, after experimental removal of surface layers of the beak horn. Here, we characterize for the first time a multilayer reflector photonic microstructure that produces the UV reflections in the king penguin beak.

Animal Communication↗
PubMed2005

Adaptive significance of avian beak morphology for ectoparasite control.

The beaks of Darwin's finches and other birds are among the best known examples of adaptive evolution. Beak morphology is usually interpreted in relation to its critical role in feeding. However, the beak also plays an important role in preening, which is the first line of defence against harmful ectoparasites such as feather lice, fleas, bugs, flies, ticks and feather mites. Here, we show a feature of the beak specifically adapted for ectoparasite control. Experimental trimming of the tiny (1-2 mm) maxillary overhang of rock pigeons (Columba livia) had no effect on feeding efficiency, yet triggered a dramatic increase in feather lice and the feather damage they cause. The overhang functions by generating a shearing force against the tip of the lower mandible, which moves forward remarkably quickly during preening, at up to 31 timesper second. This force damages parasite exoskeletons, significantly enhancing the efficiency of preening for parasite control. Overhangs longer than the natural mean of 1.6mm break significantly more often than short overhangs. Hence, stabilizing selection will favour overhangs of intermediate length. The adaptive radiation of beak morphology should be re-assessed with both feeding and preening in mind.

Adaptation, Biological↗
PubMed2003

The cellular and molecular origins of beak morphology.

Cellular and molecular mechanisms underlying differences in beak morphology likely involve interactions among multiple embryonic populations. We exchanged neural crest cells destined to participate in beak morphogenesis between two anatomically distinct species. Quail neural crest cells produced quail beaks in duck hosts and duck neural crest produced duck bills in quail hosts. These transformations involved morphological changes to non-neural crest host beak tissues. To achieve these changes, donor neural crest cells executed autonomous molecular programs and regulated gene expression in adjacent host tissues. Thus, neural crest cells are a source of molecular information that generates interspecific variation in beak morphology.

Animals↗
PubMed1995

An experimental investigation of the costs and benefits of beak trimming in turkeys.

An investigation was carried out on 504 BUT 8 female poults to identify the optimum technique and age for beak trimming breeding turkeys, which have to be kept at relatively high light intensities and are thus at serious risk of cannibalism. Different groups of birds were subjected to electronic trimming (Bio-beaking) at one day old, cold cutting (with secateurs) at six days or at 21 days, or hot cutting (with a cautery iron) at six days or 21 days old. The behaviour, production traits, feather damage, injuries and mortality of the birds were measured up to 12 weeks old. None of the methods had much effect on the behaviour or production traits, other than relatively minor reductions in beak-related activities such as pecking other birds and preening, and short term depressions of food intake and bodyweight gain, and improvements in food conversion ratio. All the beak-trimming techniques resulted in marked reductions in mortality (controls 8.7 per cent, trimmed 1.6 per cent), in injuries due to cannibalism (controls 68.1/100 birds, trimmed 9.8/100 birds) and in the scores of feather damage caused by pecking (controls 1.05, trimmed 0.29). The adverse effects of beak trimming were minor and short-lived, and were clearly outweighed by the benefits in reducing cannibalism. Of the different methods, trimming with a hot blade is not recommended. Electronic trimming appeared to offer the most benefits and caused little apparent distress, but can be hazardous in unskilled hands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Research note: genetic adaptation to multiple-bird cage environment is less evident with effective beak trimming.

Selection of hens with intact beaks for high performance in multiple-bird cages has produced a stock that clearly exceeds its unselected control when hens have intact beaks but shows less advantage when comparisons involve effectively beak-trimmed birds. The selected stock performed at about the same level as a stock recently derived from a commercial source (but with two generations of relaxed selection) when birds had intact beaks but at a lower level when birds had their beaks trimmed. Relative incidences of deaths from cannibalistic pecking were partially responsible for the results obtained.

Adaptation, Physiological↗
PubMed1992

Effect of rearing floor type and ten-day beak trimming on stress and performance of caged layers.

Beak trimming pullets at an early age is a widespread industry practice. There is some concern that this practice may have effects on the subsequent performance of the birds in the production phase. Effects of beak treatment (trimmed or untrimmed) and rearing floor type (litter or wire) on performance of caged layers were evaluated in a 2 x 2 factorial arrangement of treatments. Pullets that were trimmed or untrimmed at 10 days of age and reared on either litter or wire floors were placed in a cage house. Production factors and stress measurements were recorded to determine detrimental effects of the early trimming and rearing floor types. No interactions (P = .15) between rearing floor type and beak treatment were observed for BW, feed consumption, egg production, heart weight, spleen weight, or blood corticosterone. However, an interaction (P = .02) between rearing floor type and beak treatment was observed for adrenal weight. There were no differences (P = .08) in the final BW of the pullets. Birds reared on litter ate considerably (P = .0002) more than those reared on wire. There were no differences (P = .27) in egg production rate. Adrenal weights were different (P = .007), with the litter-raised birds having much smaller adrenals at the end of the 36-wk trial. Hearts of the beak-trimmed birds were smaller (P = .02) than those of the untrimmed birds. There were no differences in spleen weights (P = .07) or blood corticosterone levels (P = .07). Differences in the feather cover were observed.

Adrenal Glands↗
PubMed1992

Beak trimming and sex effects on behavior and performance traits of large white turkeys.

The effects of beak trimming at day old on performance and behavioral activities of male and female Large White turkeys were evaluated. One hundred and twenty poults of each sex were evenly assigned to 20 treatment pens and evaluated for body weight, feed usage, and livability characteristics to 18 wk of age. Behavioral observations were conducted for feeding, drinking, sleeping, huddling, resting, and agonistic activities. Beak trimming affected body weight and feed usage levels for the sexes differently. From 6 wk, trimmed males were significantly heavier than untrimmed males, whereas untrimmed females were heavier than trimmed females from 12 wk. Similar to body weights, feed usage levels from 13 to 18 wk were higher for trimmed males compared with untrimmed males and lower for trimmed females compared with untrimmed females. Feed conversion ratios after 12 wk and survival to 18 wk were not affected by trimming treatment. Livability rates, however, were lowest for untrimmed males and highest for untrimmed females. Effects on behavioral activities were confined primarily to the brooding and early rearing phases. Beak trimming reduced feeding activity of females and drinking activity of both males and females during the first 2 wk. Sleeping, huddling, and resting activities were increased by beak trimming for both sexes during brooding. Agonistic acts were reduced by beak trimming main effect at 3 and 6 wk. Trimmed males committed fewer agonistic acts at 6 wk than untrimmed males.

Agonistic Behavior↗
PubMed1988

Psittacine beak and feather disease syndrome in a cockatoo.

Psittacine beak and feather disease syndrome was diagnosed in an adult sulfur-crested cockatoo with a history of chronic, progressive feather loss and beak necrosis. A definitive diagnosis was made on the basis of clinical signs and the observation of intracytoplasmic and intranuclear inclusions in involved feather follicular epithelium. Psittacine beak and feather disease syndrome develops in a variety of psittacine species and usually has a progressive and irreversible clinical course. Symmetric feather loss with replacement by severely dystrophic plumage is the salient clinical finding. Beak elongation and breakage also may be found. Treatment of diseased birds remains palliative and consists of a controlled environment, balanced nutrition, antibiotics, and autogenous vaccines. Avian practitioners should include psittacine beak and feather disease syndrome as a potential cause for pathologic feather loss in caged birds.

Animals↗
PubMed2006

Beaked whale auditory evoked potential hearing measurements.

Several mass strandings of beaked whales have recently been correlated with military exercises involving mid-frequency sonar highlighting unknowns regarding hearing sensitivity in these species. We report the hearing abilities of a stranded juvenile beaked whale (Mesoplodon europaeus) measured with auditory evoked potentials. The beaked whale's modulation rate transfer function (MRTF) measured with a 40-kHz carrier showed responses up to an 1,800 Hz amplitude modulation (AM) rate. The MRTF was strongest at the 1,000 and 1,200 Hz AM rates. The envelope following response (EFR) input-output functions were non-linear. The beaked whale was most sensitive to high frequency signals between 40 and 80 kHz, but produced smaller evoked potentials to 5 kHz, the lowest frequency tested. The beaked whale hearing range and sensitivity are similar to other odontocetes that have been measured.

Acoustic Stimulation↗
PubMed2003

Body temperature in captive long-beaked echidnas (Zaglossus bartoni).

The routine occurrence of both short-term (daily) and long-term torpor (hibernation) in short-beaked echidnas, but not platypus, raises questions about the third monotreme genus, New Guinea's Zaglossus. We measured body temperatures (T(b)) with implanted data loggers over three and a half years in two captive Zaglossus bartoni at Taronga Zoo, Sydney. The modal T(b) of both long-beaks was 31 degrees C, similar to non-hibernating short-beaked echidnas, Tachyglossus aculeatus, in the wild (30-32 degrees C) and to platypus (32 degrees C), suggesting that this is characteristic of normothermic monotremes. T(b) cycled daily, usually over 2-4 degrees C. There were some departures from this pattern to suggest periods of inactivity but nothing to indicate the occurrence of long-term torpor. In contrast, two short-beaked echidnas monitored concurrently in the same pen showed extended periods of low T(b) in the cooler months (hibernation) and short periods of torpor at any time of the year, as they do in the wild. Whether torpor or hibernation occurs in Zaglossus in the wild or in juveniles remains unknown. However, given that the environment in this study was conducive to hibernation in short-beaks, which do not easily enter torpor in captivity, and their large size, we think that torpor in wild adult Zaglossus is unlikely.

Animals↗