SEARCH · PubMed Health

Results for “Beak”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

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↗

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↗

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↗

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↗

PubMed1987

Effects of beak trimming and restraint on heart rate, food intake, body weight and egg production in hens.

1. Heart rate (measured on restrained hens in two experiments) was used as an indicator of short term fear and pain responses of light and heavy strains of hens subjected to beak trimming. 2. In the first experiment 3 mm of the upper and lower mandibles was trimmed, while in the second 0, 2, 4, 6 and 8 mm of upper and lower mandibles were removed. 3. Production responses to beak trimming were measured after trimming, for 4 weeks in experiment 1 and for 10 weeks in experiment 2. 4. In the first experiment the recovery of beak trimmed hens to normal heart rate took significantly longer than that of control hens subjected only to catching and restraint, suggesting that there was short term pain associated with beak trimming. 5. The heavier strain took about 4 min longer to return to a normal heart rate than the lighter strain, indicating a strain difference in responsiveness to beak trimming. 6. Trimming the hens' beak by 3 mm had no significant effect on rate of lay or body weight, but their mean egg weight was depressed and food intake took 9 to 10 d to recover to pre-trimming values. 7. In the second experiment a plateau was reached in recovery time of the heart rate once 4 mm of beak was removed. Removal of 4, 6 and 8 mm of beak depressed normal feeding and resulted in variable effects on production and body weight.

Animals↗

PubMed1991

Region-specific expression of scutate scale type beta keratins in the developing chick beak.

This study shows that different patterns of scutate scale type beta keratins are accumulated in the three adjacent structures of the embryonic chick beak: periderm, egg tooth, and cornified beak. The cornified beak accumulates all of the beta keratins of scutate scale except pp2,3. The periderm, which is the outermost, multilayered covering of the whole embryonic beak, accumulates only beta keratins 2,3, and p2,3 of the scutate scale pattern. The egg tooth, which is the rounded elevation on the dorsal surface of the upper beak, and the embryonic claw accumulate greatly reduced levels of 2,3 and p2,3 compared to scutate scale. Like cornified beak, the claw does not accumulate pp2,3, but both tissues express a potentially new beta keratin, beta keratin 8. Neither the histidine rich "fast" proteins (HRPs), which are expressed in embryonic scutate scales and feathers, nor the avian cytokeratin associated proteins (cap-1 and cap-2), which are expressed in scutate and reticulate scales, are expressed in any of the embryonic beak structures or in the claw. The implications of these findings with regard to regulation of terminal differentiation of avian skin are discussed.

Animals↗

PubMed1976

The cells that secrete the beaks in octopods and squids (Mollusca, Cephalopoda).

A single layer of cell secrets the hard cephalopod beaks. The beccublasts are tall columnar cells that separate the beak from the surrounding buccal muscles, and must serve to attach these muscles to the beak. Within the cell layer there are three types of cells. The first, and most frequently found contain cell-long fibrils. These fibrils may have contractile and tensile properties. Complex trabeculae extend from the beccublasts into the matrix of the beak. The fibrils are attached to these trabeculae and at the other end of the cells they are anchored near to the beccublast-muscle cell interface, closely associated with the muscles that move the beak. The second group of cells contain masses of endoplasmic reticulum the cysternae of which are arranged along the long axis of the cell. These cells also contain dense granules and are probably the major source of beak hard tissue. It is probable that each cell secretes its own column of beak hard tissue. The third group of cells cells contains a mixture of fibrils and secretory tissue. In the beccublast layer there are changes in the proportion of the three types of cells depending upon the region sampled. In the region where growth is most active there are mostly secretory cells, whereas near the biting and wearing tip there are mainly anchoring type cells.

Animals↗

PubMed1988

Effects of beak trimming at different ages on the body weight and feed conversion of guinea fowl (Numida meleagris).

The effect of beak trimming at different ages on feed consumption and growth of meat-type guineas (Numida meleagris) up to 12 wk of age was investigated. In the first experiment, beaks of birds were trimmed at 7, 28, 49, and 70 days, respectively. In the second experiment, beak trimming was done at 42, 49, 56, and 63 days, respectively. Body weight, feed consumption, and mortality were measured first at 4 wk and weekly thereafter in both experiments. Beak trimming of keets at 7 days, significantly (P less than .05) reduced body weights at 4, 8, and 12 wk whereas beak trimming at 70 days significantly (P less than .05) reduced body weights at 12 wk. Beak trimming at other ages did not produce significant differences in body weights or feed conversions. Mortality was low (2 to 4%) throughout.

Age Factors↗

PubMed1989

Effects on turkey mortality and body weight of type of beak trimming, age at trimming, and injection of poults with vitamin and electrolytes solution at hatching.

This study was designed to determine the influence of: 1) age at and type of beak trimming (BT), and 2) injection of poults at hatch with 2 mL of a commercial mineral and vitamin solution versus noninjection of poults on the viability and growth rate of turkeys to market age. Mortality from 0 to 20 wk of age and BW at 8, 16, and 20 wk of age were recorded. At hatch, poults were BT 1.0 mm (Experiment 1) or 1.5 mm (Experiment 2) anterior to the nostril using an electric arc beak trimmer. In a second treatment (Experiments 1 and 2), one-third to one-half of the beak was removed at 11 days of age with a hot blade beak trimmer. In Experiment 1, offspring from three large-bodied crosses were used whereas in Experiment 2 birds were from a single large-bodied cross. The BT at 1.0 mm anterior to the nostril with an electronic beak trimmer (Experiment 1) increased mortality and decreased BW at 8, 16, and 20 wk of age relative to BT at 11 days of age with the hot blade beak trimmer. The BT at 1.5 mm (Experiment 2) at hatching did not affect mortality and reduced BW only at 8 wk of age relative to BT at 11 days of age. The use of an injectable commercial vitamin-mineral solution did not influence mortality in either experiment and significantly increased BW only at 8 wk of age in Experiment 2. The interactions of strain cross with either age of BT or injection vs. noninjection of poults were NS in Experiment 1.

Age Factors↗

PubMed1990

Influence of age at final beak trimming on pullet and layer performance.

Effects of final beak trimming on pullet and layer productivity were examined with three strains of commercial layers. All pullets were precision-trimmed at 7 days with final beak trimming at either 63, 84, or 105 days. Transient depressions of pullet body weight and feed consumption were noted in the periods immediately following beak trimming. Pullet mortality from 7 to 18 wk of age and 18-wk body weight were not significantly affected by beak trimming treatments. Strain effects were noted in rate of feed consumption following beak trimming. Age at 50% production was significantly later among birds trimmed at 63 days than among those trimmed at 84 or 105 days. Feed consumption, egg production, and mortality (140 to 441 days) were significantly lower among birds trimmed at 63 days than among those trimmed at 84 or 105 days. Egg quality and size were not influenced by beak trimming treatments.

Aging↗

PubMed1991

Beak trimming effects on behavior patterns, fearfulness, feathering, and mortality among three stocks of White Leghorn pullets in cages or floor pens.

White Leghorn pullets of the Y1, Y2, and North Central Randombred (NCR) experimental stocks were used. Half of the birds of each stock had half of the upper and less of the lower mandible removed at 4 wk of age by making a V-shaped cut as viewed from the side (BT), whereas the other half retained their beaks intact (IN). Pullets were moved from growing pens to a layer house at 18 wk of age. Seventy-two cages and 30 floor pens were filled with 6 and 20 birds per unit, respectively. Pullets within a cage or floor pen were all of the same genetic stock and beak treatment. All measurements were performed within 10 wk after housing, except for mortality in cages. When kept in cages, genetic stocks did not show behavioral differences. However, in floor pens, stock differences were detected in feeding, crouching, and nonaggressive pecking. When kept in cages, the stocks also differed in 24-wk body weight, weight gain from 18 to 24 wk, and certain measures of fearfulness in both cages and pens, and in feather condition at 21 and 22 wk. Mortality from cannibalism and hen-days survival of caged IN pullets differed among genetic stocks. Mortality from cannibalism was absent among pullets kept in experimental floor pens. In cages, BT pullets were less active, gained less weight, and had lower incidence of cannibalism than IN pullets. Also, BT pullets were less nervous and had better feather condition than IN pullets. However, trimming beaks to prevent cannibalism was less effective in NCR pullets than in Y1 or Y2 pullets. In floor pens, BT pullets showed less activity and reduced feeding frequency and less fearfulness as indicated by duration of induced tonic immobility. Agonistic behaviors were not different between BT and IN pullets. From these results, beak trimming could be interpreted as having either stressful or stress-alleviating effects, depending on the criteria used. However, proper beak trimming appears beneficial when cannibalistic pecking is likely to be a problem. The relative benefits of beak trimming vary among genetic stocks.

Agonistic Behavior↗

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↗

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↗