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At least 19 recordsLinked to original sources
PubMed1992

Beak trimming effects on beak length and feed usage for growth and egg production.

Two experiments were conducted to compare beak treatment effects on pullets of three genetic stocks. Within each stock, equal numbers were assigned to three treatments: no beak trimming (IN), beak trimming once (1X), and beak trimming twice (2X). Beak treatment, genetic stock, and age effects along with interactions among main effects were examined for production-associated traits during rearing and brief periods of early egg production. Beaks of 1X and 2X pullets remained shorter than those of IN pullets through final measurements at 36 and 32 wk of age in Experiments 1 and 2, respectively. However, differences in beak length decreased as age increased. Upper beaks of 2X pullets remained shorter than those of 1X pullets, but lower beaks of 1X and 2X pullets did not differ by 20 wk in Experiment 2. Weight gains, feed usage, and efficiency of growth were affected by beak treatments. Beak trimming reduced gains, feed eaten, feed wasted, and total feed used, and 2X pullets used their feed more efficiently for weight gain and egg production. A general decrease occurred in differences among beak treatments for weight gains, feed eaten, feed wasted, and efficiency of gains with increasing age during rearing. Nevertheless, significant differences in feed consumed, feed wasted, and efficiency of feed used for egg production indicated an economic advantage in favor of beak trimming.

Aging↗
PubMed1995

Anatomical consequences of partial beak amputation (beak trimming) in turkeys.

A detailed anatomical study was made of the effects of trimming the upper beak of turkeys. The anatomy of the normal beak was compared with that of beaks from birds which had been trimmed by one of three methods, all commonly used in the poultry industry: the Bio-Beaker which passes an electric current through the premaxilla, secateurs, or a heated blade debeaker. All three resulted in the loss of significant amounts of beak tissue. By 42 days after trimming the beak had healed with extensive regrowth, including bone and cartilage formation, and the pattern of regrowth was similar after all three methods. In the normal bird the dermis at the tip of the upper beak contains large numbers of nerve fibres and sensory receptors, but in the beak-trimmed birds the dermal tissue, although well supplied with blood vessels, was devoid of afferent nerve fibres and sensory nerve endings. In contrast with the results of previous studies with older chickens there was no evidence of neuroma formation. Trimming with secateurs was the most precise method. The heated blade damaged additional tissue close to the position of the cut, and the BioBeaker produced the most tissue damage. Behavioural studies suggested that the effectiveness of beak trimming in controlling feather pecking depends on the extent of the tissue damage.

Animals↗
PubMed1996

Beak trimming of turkeys. 1. Effects of three methods of beak trimming on body weight and mortality of six genetic lines.

An experiment was designed to compare BW and mortality of turkeys when three methods of beak trimming were utilized. Turkeys from six genetic lines were assigned to three beak trimming methods: arc beak trimming at hatching, hot-blade block trimming at 13 d, or hot-blade top-beak-only trimming at 13 d. Beak trimming method influenced 8-wk BW of three lines of females, but did not affect female BW at 16 wk. Beak trimming method influenced 8-wk BW of males from one line and 16-wk BW of a different line. There were no effects of method of beak trimming on 20-wk BW of either males or females from any line. Neither lines nor beak treatments differed in mortality.

Age Factors↗
PubMed1997

Beak trimming of turkeys. 2. Effects of arc beak trimming on weight gain, feed intake, feed wastage, and feed conversion.

An experiment was conducted to study the effects of arc beak trimming on feed consumption, weight gain, and feed wastage in males and females from two large-bodied strains and one medium-bodied strain of turkeys. Birds were placed in wire-floored battery cages from 3 to 8 wk of age and feed intake, weight gains, and feed spilled into dropping pans were recorded for each of the 5 wk of each trial. Feed conversion was calculated as feed consumed divided by weight gained. Sex by beak trimming interactions were not found. Beak trimming reduced feed wastage of the two large-bodied strains, but did not affected feed wastage of the medium-bodied strain, which did not consume as much feed as the large-bodied strains. The results of this study support the hypothesis that beak trimming reduces feed wastage of large-bodied turkeys.

Analysis of Variance↗
PubMed1986

Neuroma formation following partial beak amputation (beak trimming) in the chicken.

Branches of the trigeminal nerve, which innervates the beak in the chicken, were damaged after partial beak amputation (beak trimming) and degeneration in the nerve extended from 2 to 3 mm proximal to the cut stumps. Within 10 days the damaged nerves showed regeneration and axon sprouts had been formed. This neural regeneration was rapid so that by 20 to 30 days bundles of regenerating fibres were present and neuromas formed adjacent to the scar tissue of the stump of the beak. These neuromas became more extensive over the 70 day observation period.

Amputation, Surgical↗
PubMed1989

Behavioural consequences of partial beak amputation (beak trimming) in poultry.

1. The effects of beak trimming on 16-week-old Brown Leghorn hens, housed individually in battery cages, was assessed by comparing their behaviour after trimming with their behaviour before trimming and with the behaviour of a sham-operated control group. 2. In the short-term, times spent feeding, drinking and preening decreased. 3. In the long-term, times spent preening and pecking at the cage decreased and times spent standing inactive increased, with no signs of returning to pretreatment values after 5 weeks. 4. During the first three weeks, times spent feeding and drinking decreased and during the first two weeks, times spent sitting dozing increased, but after 5 weeks these had returned to near pre-treatment values. 5. It is argued that pain is the most probable cause of these behavioural changes. 6. The decrease in welfare to the individual bird caused by this pain will conflict with any increase in welfare to the flock brought about by beak trimming; this should be considered before any decision to beak trim is taken.

Amputation, Surgical↗
PubMed1985

Neuroma formation and abnormal afferent nerve discharges after partial beak amputation (beak trimming) in poultry.

Following partial amputation of the beak recordings were taken of the electrical activity from single afferent fibers of the intramandibular nerve. A total of 192 single afferent fiber units were isolated of which 47 were classified as nociceptors, with an abnormal pattern of discharge, and 89 were abnormal spontaneously active units. Following amputation neuromas were developing by 15 days after surgery and they were well formed by 20 to 30 days. The presence of neuromas together with abnormal spontaneous activity originating from them raise serious welfare questions concerning beak trimming.

Animals↗
PubMed2003

Psittacine beak and feather disease: a first survey of the distribution of beak and feather disease virus inside the population of captive psittacine birds in Germany.

Psittacine beak and feather disease (PBFD) is the most common viral disease of wild and captive psittacine birds. Here, we designed the first survey to investigate the existence of subclinical infections and the distribution of the causative agent named beak and feather disease virus (BFDV) inside the population of captive psittacine birds in Germany. DNA was isolated from feathers of 146 symptom-free birds from 19 different genera (all psittaformes) taken from 32 independent breeders from all over Germany. The presence of BFDV was analysed by performing polymerase chain reaction assays. Fifty-eight (39.2%) samples were found to be positive for BFDV. As expected, there was no significant predominance of one sex to be infected with BFDV.

Animals↗
PubMed2006

The calmodulin pathway and evolution of elongated beak morphology in Darwin's finches.

A classic textbook example of adaptive radiation under natural selection is the evolution of 14 closely related species of Darwin's finches (Fringillidae, Passeriformes), whose primary diversity lies in the size and shape of their beaks. Thus, ground finches have deep and wide beaks, cactus finches have long and pointed beaks (low depth and narrower width), and warbler finches have slender and pointed beaks, reflecting differences in their respective diets. Previous work has shown that even small differences in any of the three major dimensions (depth, width and length) of the beak have major consequences for the overall fitness of the birds. Recently we used a candidate gene approach to explain one pathway involved in Darwin's finch beak morphogenesis. However, this type of analysis is limited to molecules with a known association with craniofacial and/or skeletogenic development. Here we use a less constrained, complementary DNA microarray analysis of the transcripts expressed in the beak primordia to find previously unknown genes and pathways whose expression correlates with specific beak morphologies. We show that calmodulin (CaM), a molecule involved in mediating Ca2+ signalling, is expressed at higher levels in the long and pointed beaks of cactus finches than in more robust beak types of other species. We validated this observation with in situ hybridizations. When this upregulation of the CaM-dependent pathway is artificially replicated in the chick frontonasal prominence, it causes an elongation of the upper beak, recapitulating the beak morphology of the cactus finches. Our results indicate that local upregulation of the CaM-dependent pathway is likely to have been a component of the evolution of Darwin's finch species with elongated beak morphology and provide a mechanistic explanation for the independence of beak evolution along different axes. More generally, our results implicate the CaM-dependent pathway in the developmental regulation of craniofacial skeletal structures.

Animals↗
PubMed1994

The effect of beak trimming on two strains of commercial tom turkeys. 1. Performance traits.

Two commercial strains (Strains A and B) of tom turkeys were either beak trimmed or left with intact beaks. These strains responded similarly to beak trimming for performance traits, with the exception of a higher incidence of beak-inflicted injuries among Strain B toms with intact beaks. Turkeys with trimmed beaks had higher body weights at 8, 12, and 16 wk. Feed efficiency was better in beak-trimmed birds from 4 to 8 wk, 12 to 16 wk, and 0 to 18 wk. Beak treatment did not effect mortality. Leg abnormalities caused the majority of culling or resulted in death or culling from beak-inflicted injuries. Beak trimming seems to be a beneficial practice in tom turkeys because feed efficiency of beak-trimmed toms was improved and injuries were reduced in a strain that tended to exhibit a high degree of beak-inflicted injuries. The results suggest that the need for beak trimming tom turkeys may be reduced when feed efficiency of toms with intact beaks is improved.

Animals↗
PubMed2004

Beak gape dynamics during song in the zebra finch.

Bird song is a complex communication behavior that requires the coordination of several motor systems. Sound is produced in the syrinx and then modified by the upper vocal tract, but the specific nature and dynamics of this modification are not well understood. To determine the contribution of beak movements to sound modification, we studied the beak gape patterns in zebra finches (Taeniopygia guttata). Subsyringeal air sac pressure and song were recorded together with changes in beak gape, which were monitored with a magneto-sensitive transducer. Beak gape was positively correlated with fundamental frequency, peak frequency, and subsyringeal air sac pressure in all but one bird. For harmonic stacks, peak frequency increased with increasing beak gape, and the relationship between fundamental frequency and beak gape was no longer significant. Experimentally holding the beak open or closed had acoustic consequences consistent with the model in which beak movements change upper vocal tract length and, thus, the filter properties. Beak gape was positively correlated with sound amplitude in all but two birds. The relationship between beak aperture and amplitude may, however, be indirect because air sac pressure is correlated with amplitude and beak gape. The beak is opened quickly and to its widest aperture immediately prior to the onset of sound and at rapid transitions in sound, suggesting that beak movements may affect vibratory behavior of the labia.

Acoustics↗
PubMed1991

Selection and beak-trimming effects on behavior, cannibalism, and short-term production traits in White Leghorn pullets.

Pullets of stocks derived from the North Central Randombred White Leghorn population without selection (C) or selected (S) on family performance when kept with beaks intact in multiple-hen cages were compared. Pullets had intact, one-fourth, or one-half of the beak removed (IN, 1/4R, and 1/2R, respectively). No stock differences were detected for behavior traits or other measures during the rearing period. However, beak-trimmed pullets were more inactive and feeding behavior was depressed in 1/2R pullets 1 wk after beak trimming. At 16 wk, 1/4R pullets' beaks had regrown but 1/2R pullets' beaks continued to be shorter than IN pullets' beaks. No differences in fearfulness were found between genetic stocks or among beak length treatments early in the laying period. Deaths from beak-inflicted injuries accumulated steadily from 18 wk until the study was ended at 40 wk. Cannibalistic deaths occurred less frequently in S as compared with C pullets within each beak treatment. As the amount of beak removal increased, beak-inflicted mortality decreased. The S pullets had earlier sexual maturity, lighter egg weights, and greater hen-housed egg production and egg mass than C pullets, and 1/2R pullets had greater egg production than 1/4R and IN pullets. Genetic stock by age and beak treatment by age interactions were present for hen-housed production and egg mass, and the interactions appeared to result primarily from increased mortality from cannibalistic pecking with increased age.

Analysis of Variance↗
PubMed1996

The absence of neuromas in beaks of adult hens after conservative trimming at hatch.

OBJECTIVE: To determine the effects of the amount of break removed and cauterisation time on neuroma formation in hens. DESIGN: A pathology study with controls. ANIMALS: Twenty domestic fowl were beak-trimmed. Three non-beak-trimmed domestic fowl were used as controls. PROCEDURE: Beaks of two age groups with two levels of beak removal and either 2 s or 4 s cauterisation, were investigated macroscopically and microscopically for deformities. RESULTS: Scattered trauma-associated neuromas were present in the beaks of pullets 10 weeks after moderate trimming at hatch. Neuromas were not present in beaks of adult hens that had been similarly trimmed. Sensory corpuscles were present 10 and 70 weeks after moderate trimming, though fewer in number than in intact control hens. In contrast, trauma-associated neuromas persisted in beaks of 70-week-old hens that had been severely trimmed at hatch. A range of deformities that were absent in moderately trimmed hens, were observed in hens with severely trimmed beaks. Receptors were not seen in severely trimmed beaks. CONCLUSION: Beak-trimming at hatch induces the formation of neuromas, regardless of the amount of tissue removed. There is a critical amount of beak tissue that can be removed, beyond which trauma-associated neuromas will not resolve, but will persist in mature hens.

Amputation, Surgical↗
PubMed2006

Morphoregulation of avian beaks: comparative mapping of growth zone activities and morphological evolution.

Avian beak diversity is a classic example of morphological evolution. Recently, we showed that localized cell proliferation mediated by bone morphogenetic protein 4 (BMP4) can explain the different shapes of chicken and duck beaks (Wu et al. [2004] Science 305:1465). Here, we compare further growth activities among chicken (conical and slightly curved), duck (straight and long), and cockatiel (highly curved) developing beak primordia. We found differential growth activities among different facial prominences and within one prominence. The duck has a wider frontal nasal mass (FNM), and more sustained fibroblast growth factor 8 activity. The cockatiel has a thicker FNM that grows more vertically and a relatively reduced mandibular prominence. In each prominence the number, size, and position of localized growth zones can vary: it is positioned more rostrally in the duck and more posteriorly in the cockatiel FNM, correlating with beak curvature. BMP4 is enriched in these localized growth zones. When BMP activity is experimentally altered in all prominences, beak size was enlarged or reduced proportionally. When only specific prominences were altered, the prototypic conical shaped chicken beaks were converted into an array of beak shapes mimicking those in nature. These results suggest that the size of beaks can be modulated by the overall activity of the BMP pathway, which mediates the growth. The shape of the beaks can be fine-tuned by localized BMP activity, which mediates the range, level, and duration of locally enhanced growth. Implications of topobiology vs. molecular blueprint concepts in the Evo-Devo of avian beak forms are discussed.

Animals↗
PubMed2004

The effects of different beak trimming techniques on plasma corticosterone and performance criteria in Single Comb White Leghorn hens.

DeKalb XL chicks were given a beak trim at 6 d of age (6DP) with a 2.8-mm gauge and a beak trim at 11 wk (11WB) with a block cut approximately 2 mm anterior to the nasal openings. Corticosterone (CS) levels of the 6DP treatment were (P < or = 0.01) elevated above nontrimmed CS levels at 2 h posttrim; and BW and feed consumption (FC) of the 6DP were depressed until 8 wk of age. At 11 wk of age, CS of the 11WB treatment was (P < or = 0.02) elevated above controls at 1, 2, 8, and 5 wk posttrim. The 11WB treatment resulted in a decrease in FC and a reduction in BW at 12, 14, and 16 wk of age, whereas there were no differences among treatments in livability during the pullet phase. At 72 wk of age, FC of the nontrimmed controls was greater than both beak trimmed treatments, and both beak trimmed treatments had greater hen housed eggs, percentage hen day egg production, and percentage livability. Both beak trimmed treatments resulted in better egg income, feed cost per hen, and net income (NI). The 6DP and 11WB beak trim treatments resulted in an improvement of NI per hen of 1.48 dollars and 1.86 dollars, respectively. In addition, both beak trimmed treatments exhibited better feather score and Hansen's test (fearfulness). It was concluded that pullets and hens could adapt to the physiological stress of beak trimming and out perform, during a lay phase, controls whose beaks were not trimmed.

Animal Husbandry↗
PubMed2004

Vocal mechanics in Darwin's finches: correlation of beak gape and song frequency.

Recent studies of vocal mechanics in songbirds have identified a functional role for the beak in sound production. The vocal tract (trachea and beak) filters harmonic overtones from sounds produced by the syrinx, and birds can fine-tune vocal tract resonance properties through changes in beak gape. In this study, we examine patterns of beak gape during song production in seven species of Darwin's finches of the Galápagos Islands. Our principal goals were to characterize the relationship between beak gape and vocal frequency during song production and to explore the possible influence therein of diversity in beak morphology and body size. Birds were audio and video recorded (at 30 frames s(-1)) as they sang in the field, and 164 song sequences were analyzed. We found that song frequency regressed significantly and positively on beak gape for 38 of 56 individuals and for all seven species examined. This finding provides broad support for a resonance model of vocal tract function in Darwin's finches. Comparison among species revealed significant variation in regression y-intercept values. Body size correlated negatively with y-intercept values, although not at a statistically significant level. We failed to detect variation in regression slopes among finch species, although the regression slopes of Darwin's finch and two North American sparrow species were found to differ. Analysis within one species (Geospiza fortis) revealed significant inter-individual variation in regression parameters; these parameters did not correlate with song frequency features or plumage scores. Our results suggest that patterns of beak use during song production were conserved during the Darwin's finch adaptive radiation, despite the evolution of substantial variation in beak morphology and body size.

Acoustics↗
PubMed1977

Cell turnover in the beak of Rana pipiens.

Rana pipiens tadpoles were injected with 3H-thymidine at different stages to label basal cells of the horny beaks, the keratinized oral specializations of many anuran tadpoles. Cells in the column and sheath of the beak are derived from the basal layer. Movement of the labeled cells in beak columns can be traced, permitting calculation of the rate of cell addition into the columns. With the counts of the total number of column cells and cell addition rate, the rate of apical cell loss from a column throughout the larval stages can also be calculated. The rate of cell addition decreases steadily from stage III through stage XX, in all portions of both beaks. The rate of change of these column cell addition rates is similar among middle and lateral portions of both upper and lower beaks. There is a relatively constant rate of cell loss until stage XII or XIII. It then increases sharply, and the beaks are completely lost at stages XIX or XX. The longer, lower beak columns have a much faster cell loss rate than do the upper beak columns at late larval stages. Life spans for cells that move to the sheath may be about one-half those for cells that enter the beak columns, It is suggested that thyroid hormone accelerates the rate of column cell loss.

Age Factors↗
PubMed2004

Analysis of dose conformity and normal-tissue sparing using two different IMRT prescription methodologies for irregularly shaped CNS lesions irradiated with the Beak and 1-cm MIMiC collimators.

PURPOSE: To determine whether intensity modulated sequential tomotherapy using the NOMOS Beak provides superior dose conformity and organ sparing to the MIMiC "1-cm" mode, and if so, to identify a subset of patients most likely to benefit from Beak intensity modulated sequential tomotherapy. METHODS AND MATERIALS: Twelve patients with irregularly shaped central nervous system tumors were selected for intensity modulated radiation therapy planning. Two treatment plans, one using the Beak collimator and the other using the 1-cm MIMiC collimator, were generated for each patient with identical anatomic contouring, prescriptions, and optimization algorithms. The Beak attaches to the MIMiC collimator and truncates the 1-cm MIMiC mode beamlet size from 1.00 x 0.85 cm(2) to 1.00 x 0.39 cm(2) at isocenter. Conformity indexes were calculated for each lesion using two different prescription methodologies, and mean doses to critical structures were recorded. RESULTS: For the first prescription methodology using uniform prescribed isodose, mean conformity index was 2.19 (range, 1.33-3.90) for the Beak compared to 2.67 (range, 1.64-4.75) for the 1-cm mode (p = 0.0003). Mean doses to the brainstem, right orbit, and left optic nerve were significantly lower with the Beak than with the 1-cm mode (p = 0.0150, 0.0068, and 0.0284, respectively). For the second prescription methodology using uniform target volume coverage prescription, mean conformity index was 2.04 (range, 1.56-2.70) for the Beak compared to 2.73 (range, 1.70-8.58) for the 1-cm mode (p = 0.07). Mean doses to the brain, brainstem, optic chiasm, right optic nerve, left optic nerve, and left orbit were significantly lower with the Beak than with the 1-cm mode (p = <0.0001, <0.0026, <0.0016, <0.0076, <0.0007, and <0.046, respectively). CONCLUSION: Beak intensity modulated sequential tomotherapy is superior to the 1-cm MIMiC mode for irregularly shaped central nervous system tumors, because it provides better conformity and critical organ sparing. These differences may allow for safer dose escalation and retreatment, so the method presents an alternative to gamma knife stereotactic radiosurgery.

Algorithms↗