Transdural circumferential decompression for thoracic spinal stenosis caused by beak-type ossification of the posterior longitudinal ligament: a technical note.

PURPOSE: Thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine is usually progressive and responds poorly to conservative therapy, making surgery the only effective treatment option. A variety of surgical procedures have been developed to treat thoracic OPLL. However, the optimal surgical approach for removal of thoracic OPLL remains unclear. In the present study, we described a newly modified posterior approach for the removal of OPLL: circular decompression via dural approach, and complete removal of OPLL can be achieved under direct vision and without neurological deficit. MATERIALS AND METHODS: Three patients with beak-type thoracic OPLL presented with progressive thoracic myelopathy and leg weakness. Magnetic resonance imaging showed the spinal cord severely compressed. The surgical management of the three patients involved the 'cave-in' circular decompression and transdural resection of OPLL. RESULTS: Transdural circumferential decompression was successfully performed in all three patients. Clinical outcome measures, including pre- and postoperative radiographic parameters, were assessed. All of the patients were followed up for an average of 12 months (ranging from 10 to 15 months), and no surgery-related complications occurred. Weakness relief and neural function recovery were satisfactorily achieved in all patients by the final follow-up. CONCLUSIONS: Transdural circumferential decompression was an effective method for thoracic spinal stenosis caused by concurrent beak-type OPLL, by which OPLL could be safely removed. It is especially useful when there is a severe adhesion between the dura OPLL.

Comparison of 3D-printed Titanium Alloy and Polyether Ether Ketone Prosthetic Beaks for an Injured Red-crowned Crane (Grus japonensis).

The red-crowned crane (Grus japonensis) is a critically endangered species. Three-dimensional-printed prosthetic beaks made of titanium alloy and polyether ether ketone (PEEK) were used to repair the beak of a red-crowned crane that had a complete fracture of the anterior maxillary bone and rhinotheca. The physical properties and stability of the prostheses and changes in the crane's behaviors after application of either beak were evaluated. The titanium alloy and PEEK prosthetic beaks weighed 30.81 g and 5.9 g, respectively. Scanning electron microscopy showed differences in microstructure between the 2 materials and the true beak; the true beak was softer than both materials from which the prostheses were made. The titanium beak frequently detached, and the residual natural beak showed significant cuticle softening with this prosthetic beak. The titanium beak detached within an approximately 3-month period after placement, whereas the PEEK prosthetic beak has remained secure for 2 years. Moreover, the crane's foraging times (P < .01) and grooming times (P < .05) with the titanium alloy false beak were lower than the normal, red-crowned crane. With the PEEK beak, no detachment or cuticle softening occurred, and foraging and grooming behaviors were evaluated by the investigators as natural (P > .05). Based on the results of this clinical case, the PEEK prosthetic beak was found to be superior to the titanium alloy prosthetic beak in color, weight, firmness, and postoperative effects.

Transsinus Pinning to Correct Lateral Deviation of the Upper Beak in Juvenile Macaws.

Lateral deviation of the upper beak ("scissor beak" or "wry beak") is a common malocclusion in many species of birds but appears to be a common presentation in macaws (Ara species). This article describes transsinus pinning, a procedure in which a pin is passed through the frontal sinuses, turned parallel to the upper beak, and attached to the tip of the beak with an orthodontic rubber band to provide constant tension on the beak as it grows. The tension of the rubber band is maintained until the beak is considered straight. The results of 16 cases in which this beak-straightening procedure was used are presented. The age of the chicks that had their beaks straightened ranged from 7 to 28 weeks, and they were placed into 2 groups: those younger than 12 weeks (12 chicks; 75%) and those older (4 chicks; 25%). Complete resolution was achieved in 87.5% (14 of 16) of the avian patients that were treated with this procedure. The 2 remaining cases (12.5%) failed to fully respond. The 12 younger birds (75%; age, 7-12 weeks; median, 10 weeks; range, 5 weeks) responded to treatment within 2 weeks (12-85 days; median, 14 days; range, 73 days); the remaining 4 older chicks (25%; age, 14-28 weeks; median, 17.5 weeks; range, 14 weeks) required a longer period (13-90 days; median, 25.5 days; range, 77 days) for the beak to straighten. Transsinus pinning is a simple, effective, and rapid technique for correcting this malocclusion in macaw chicks younger than 16 weeks old. With this approach, in most cases, excellent results can be expected in only 2-4 weeks.

Closed Reduction of a Rostroparasphenopalatal Luxation in a Red-crowned Parakeet (Cyanoramphus novaezelandiae).

A 1-year-old red-crowned parakeet (Cyanoramphus novaezelandiae) was presented with an acute onset of hyperprotraction of the upper beak and an inability to return the beak to its normal position. With the abnormal beak position, the bird was unable to eat. Standard radiographic images of the head supported a diagnosis of a rostroparasphenopalatal luxation. The luxation was reduced with a 23-gauge hypodermic needle inserted dorsal to the palatine bone and directed ventrally. After the procedure, the bird regained its normal beak function within 2 hours.

The effects of environmental enrichment and beak-trimming during the rearing period on subsequent feather damage due to feather-pecking in laying hens.

This experiment investigated effects of environmental enrichment and beak-trimming during the rearing period on behavior in rearing and plumage damage later in life. Treatments were applied in a 2 × 2 factorial arrangement. Half of the birds were beak-trimmed at 1 d of age using an infra-red laser. A follow-up light-trim was performed at 11 wk of age with a hot blade. Environmental enrichment consisted of pecking strings, whole oats in the litter, and greater litter depth. Sixteen pens of 50 ISA Brown laying hens were used. Four pullets were selected from each pen as focal birds and observed in their home pens between 3 and 14 wk of age. Plumage damage was scored at the end of the experiment in wk 43. Beak-trimmed birds performed less ground-pecking (P = 0.003), less severe feather-pecking (P = 0.021) and more gentle feather-pecking (P = 0.018) than their non-trimmed counterparts during the rearing period. These birds also exhibited less feather damage in wk 43 (P < 0.001). The results indicate that gentle feather-pecking during rearing is not related to plumage damage when older. Additionally, higher rates of ground-pecking and severe feather-pecking during rearing may be predictive of plumage damage later in life. There was no effect of enrichment on plumage damage. It was concluded that while there was no effect on enrichment, beak-trimming appeared to be effective in reducing plumage damage in wk 43.

Effect of partial comb and wattle trim on pullet behavior and thermoregulation,1.

The wattles and comb of chickens are important for thermoregulation allowing for heat exchange during high temperatures. These integumentary tissues are sometimes trimmed to prevent tears if caught on cage equipment and to also improve feed efficiency; however, the procedure itself could be painful to chicks. Our objective was to determine the effect of trimming the comb and wattles on behavior, BW, feed usage, and the surface temperature of pullets. The wattles and comb of Leghorns were partially trimmed at 21 d age (n = 6 cages, 13 chicks each) with another 6 cages serving as controls. Behaviors were recorded 3 times daily for 1 h starting at 0800, 1200, and 1500 using instantaneous scan sampling observations conducted every 5 min prior to, on the d of, and after the trim. Group BW at 21, 28, and 36 d age and the amount of feed used for 7 d beginning at 21 and 29 d age were measured per cage. At 1300 h on d before and after the trim, thermal images of the pullet's beak, comb, eye, wattle, and shank were randomly taken on 3 pullets/cage. Smaller proportions of trimmed chicks were eating and greater proportions were sitting on the d of the trim as compared to the controls with the opposite trend occurring on 4 d post-trim (treatment by age interaction, P = 0.03 and 0.0001, respectively). Standing behavior differed only on the d of the trim where smaller proportions of trimmed pullets stood as compared to intact controls (treatment by age interaction, P = 0.0002). Trimming the comb and wattles did not affect preening, running, BW, feed utilization, and the surface temperature of the pullet. The indices of behavior suggest that on the d of the trim, pullets may have experienced temporary distress, but they returned to normal behavior by 5 h post-trim with no long-term effect on BW, feed usage, or surface body temperature.

Relationships between beak condition, preening behavior and ectoparasite infestation levels in laying hens.

The effects of beak condition on ectoparasite populations and preening in laying hens were investigated. Beak-trimmed and beak-intact caged Hy-Line W-36 hens were infested with either chicken body lice or northern fowl mites using a 2×2 factorial design with 4 replicate cages (each containing 2 hens)/treatment: 1) BTL: (beak-trimmed lice-infested); 2) BTM: (beak-trimmed mite-infested); 3) BIL: (beak-intact lice-infested); and 4) BIM: (beak-intact mite-infested). Mite scores and lice numbers were estimated weekly. Hens were video recorded the wk before infestation and at wk 6 and 9 post-infestation. Time spent preening on 6 body areas and in total were analyzed using a repeated measures ANOVA. There was a wk×beak condition interaction for lice loads, with BTL harboring approximately 17 times more lice than BIL from wk 7 to 10 post-infestation (P<0.0001). Beak condition affected mite loads (P<0.0001), with BTM having a higher mite score (3.8±0.26) than BIM (1.4±0.26). At peak infestation, BTL spent more total time preening (P=0.02, s±SE: 232.1±37.6) than prior to infestation (33.9±37.6) and directed their preening behavior towards the vent. In contrast, BIL (73.9±37.6), BTM (9.4±1.6), and BIM (8.6±1.6) did not increase total time spent preening over pre-infestation levels (103.6±37.6, 5.8±1.6, 6.7±1.6 respectively), although BTM did redirect their preening behavior toward the vent. This study confirmed previous studies showing that an intact beak is important for reducing ectoparasite infestations. Preening behavior increased in response to lice infestation, but only in beak-trimmed hens; preening behavior and louse load were correlated at peak infestation. In contrast, mite infestation did not lead to increased preening, and there was no correlation between preening and mite load. However, both lice- and mite-infested hens directed preening behavior predominantly towards the vent where these parasites are typically found.

Modelling of feather pecking behavior in beak-trimmed and non-beak-trimmed crossbred laying hens: variance component and trait-based approach.

Because of a ban on the use of beak trimming in some European countries, feather pecking is becoming a substantial problem in the layer industry, both from animal welfare and economic points of view. The feather condition score (FCS) as a measure of feather damage has been shown to be closely related to feather pecking behavior in laying hens housed in groups. To obtain a better understanding of genetic and other biological mechanisms underlying feather pecking behavior, data on FCS of a population of 2,724 female offspring from crossing 50 male W1 and 907 female WB purebred lines were used. The offspring of 25 sires were beak-trimmed, and the offspring of another 25 sires were non-beak-trimmed. Titers of plasma natural antibody (NAb) isotypes IgM and IgG binding keyhole limpet hemocyanin at 24 wk of age were measured. Feather condition was scored at 53 wk of age. In the first part of the present study, we estimated genetic parameters for FCS with 2 variance components models: a traditional linear animal model and a model combining direct and associative genetic effects. In the second part of the present study, a trait-based analysis for FCS was conducted to investigate whether NAb isotype titers can explain variation in FCS among individuals, by fitting a linear mixed model. Though the estimated associative genetic variance was substantial, associative effects for FCS were not statistically significant in both populations (P = 0.09 in beak-trimmed birds, and P = 0.08 in non-beak-trimmed birds). This suggests an insufficient number of records on FCS. Individual's NAb isotypes titers did not show direct effect for FCS of itself, but individual's IgG titers showed a suggestive effect on the FCS of cage mates (associative effect) in beak-trimmed laying hens, which need further confirmation.

Effect of substrate provision on performance and behaviour of laying hens in the pecking and scratching area of furnished cages.

1. An experiment was set up to study the effects of substrate provision on performance and behaviour in the pecking and scratching area (PSA) of non-beak-trimmed hens housed in large furnished cages (60 hens/cage). 2. Three layer hybrids (two brown and one white, ISA-Hendrix Genetics, France) and two substrate conditions (with or without wheat bran automatically distributed on the PSA) were compared in a 3 × 2 experimental design with 12 cages per treatment. 3. Substrate distribution improved laying rate with no impact on the frequency of dirty or cracked eggs. 4. Substrate distribution improved the viability and body integrity of hens, which were not beak-trimmed. 5. Distribution of substrate tended to increase the number of hens in the PSA and enhanced their pecking and scratching behaviours but had a negative impact on the number of dust bath bouts per cage and encouraged dust bathing on the wire floor close to the feeder. 6. The white hens laid more eggs in the nest than the brown birds and used the PSA more for pecking, scratching and dust bathing at the end of the day than the brown hens, underlining the necessity to adapt cage furnishing and rearing management to specific behaviours of each layer genotype.

Application of 3D-printed prosthetic lower beak in an Oriental stork (Ciconia boyciana).

To our knowledge, ours is the first case of applying a 3D-printed prosthetic beak to an Oriental stork (Ciconia boyciana). A stork in captivity underwent several surgeries for beak fractures, but the lower-mandible fractures failed to be repaired. Therefore, we applied a patient-specific beak prosthesis of titanium alloy and nylon. Because the prosthetic beak could not be maintained due to mandible and soft-tissue inflammation, the stork was euthanized. Still, we confirmed typical behavior and feeding for ~3 months after surgery. This report highlights some of the challenges we encountered and identifies process improvements required for a more successful surgery.

Grey parrot (Psittacus erithacus) beak papillae and nerves identified using novel 2-D and 3-D imaging modalities.

OBJECTIVE: The avian beak is a complex organ containing bone, neurovascular tissue, and keratinized covering (rhamphotheca). Nerve-rich papillae extend through bone into rhamphotheca providing sensory input from the beak tip. Beak trimming is a common procedure in avian species and is used for corrective, cosmetic, and behavioral modification purposes. Yet, practitioners are not well versed in complete beak anatomy, and therefore, beak trimming often disregards neurovasculature, injuring the patient and hampering recovery. Here, using comprehensive anatomical description, we aim to provide recommendations on how to safely perform beak trimming without damaging underlying sensory papillae. ANIMALS: Here, we evaluated beaks of 2 deceased grey parrots (Psittacus erithacus). PROCEDURES: In one, we used a novel stain and microcomputed tomography to visualize papillae in the upper and lower beaks. In a second, we hand isolated the upper and lower beak dermal papillae and used high-resolution photography plus traditional paraffin histology. RESULTS: Papillae and their nerves were easily identified in these 2- and 3-dimensional approaches. This allowed us to determine the approximate lengths of papillae within the upper and lower beak. CLINICAL RELEVANCE: Based on these findings, the authors recommend lateral radiographs of the bird's head and beak to identify the location of the underlying bone relative to the overlying rhamphotheca before performing beak trims. Specifically in grey parrots, the authors recommend the upper and lower beak should not be trimmed closer than 8 to 10 mm from the underlying bone. Further work is needed to support these recommendations and provide guidelines for other species.

Effects of different infrared beak treatment protocols on chicken welfare and physiology.

Infrared beak trimming provides an alternative to conventional trimming, purporting to provide a welfare-friendly means of trimming. The infrared system can be adjusted to use multiple plate and power settings. In the present study, we used 2 different plate sizes (27/23C, less severe; 25/23C, more severe) with each of 3 power settings: high (52), moderate (48), and low (44). These birds, along with conventionally (hot blade; HB) trimmed birds were maintained in an industry egg-laying facility. Physiological and behavioral measures were taken at 5, 10, 20, and 30 wk. All birds followed a similar growth curve; birds from the 27/23C (48) protocol were the heaviest across all ages and 25/23C (44) birds were the lightest. Upper and lower beak growth curves showed birds trimmed with 25/23C protocols had shorter upper and lower beaks compared with 27/23C protocols or HB. Birds trimmed using 27/23 (44) and (48) had consistently longer upper and lower mandibles. Amount of feed wasted was greatest in HB and 27/23C birds and tended to be reduced in 27/23 (48) and 25/23 (48) and (52) birds (P < 0.10). Beak-related behaviors (eating, drinking, and pecking) were measured to observe the effects of trimming protocol on beak usage, which could indicate beak pain or morphological changes that inhibit normal behaviors. Walking behavior was also measured to assess overall activity. Behavior analysis revealed that compared with HB-trimmed birds, those of 27/23C protocols walked and drank more at a young age. At 5 and 10 wk of age, a test feather was attached to the cage and pecking at as well as the damage score of the feather were determined. Birds from 27/23C (44) and (48) protocols pecked significantly more at the feather than HB, whereas HB and 25/23C (52) birds had the highest damage score. The results from the study suggest that infrared protocols can be optimized for superior productivity as well as animal well-being.

Effect of beak trimming at hatch and the inclusion of oat hulls in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract traits of brown-egg pullets from hatch to 15 weeks of age.

The influence of infrared beak trimming at hatch (IRBT) and the inclusion of oat hulls (OH) in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract (GIT) development, was studied in brown-egg pullets from 0 to 15 wk of age. The experimental design was completely randomized with 4 treatments arranged as a 2 × 2 factorial with IRBT (sham vs. treated) and OH inclusion (0 vs. 3%) as main effects. Each treatment was replicated 20 times and the experimental unit was a cage with 10 pullets. Feed intake (FI), BW gain, feed conversion ratio (FCR), energy intake (EI, kcal AMEn/d), and energy conversion ratio (ECR, kcal AMEn/g of BW gain) were determined by feeding period (0 to 6, 7 to 10, and 11 to 15 wk of age) and cumulatively. Particle size preference was measured at 7 wk and exploratory pecking behavior of the pullets and at 8 to 14 wk of age. From 0 to 6 wk of age, beak trimming decreased FI (P < 0.01) and increased pullet mortality (P < 0.001) but did not affect BW gain. From 0 to 15 wk of age, OH inclusion improved BW uniformity (P = 0.090) but impaired FCR (P < 0.05) without showing any effect on BW gain or ECR. Preference for coarse particles was greater for the sham than for the treated pullets. Beak trimming and OH feeding reduced (P < 0.05) the exploratory pecking behavior of the pullets from 8 to 12 wk of age but not thereafter. Oat hulls increased the relative weights of the full gizzard and intestines at all ages (P < 0.05). In summary, beak trimming did not affect pullet performance at 15 wk of age or GIT development at any age. Oat hulls improved GIT development at all ages but did not affect BW or ECR. Both beak treatment and OH inclusion affected particle size preference and reduced the exploratory pecking behavior of the birds.

Review: Key tweaks to the chicken's beak: the versatile use of the beak by avian species and potential approaches for improvements in poultry production.

The avian beak is a multipurpose organ playing a vital role in a variety of functions, including feeding, drinking, playing, grasping objects, mating, nesting, preening and defence against predators and parasites. With regards to poultry production, the beak is the first point of contact between the bird and feed. The beak is also manipulated to prevent unwanted behaviour such as feather pecking, toe pecking and cannibalism in poultry as well as head/neck injuries to breeder hens during mating. Thus, investigating the beak morphometry of poultry in relation to feeding and other behaviours may lead to novel insights for poultry breeding, management and feeding strategies. Beak morphometry data may be captured by advanced imaging techniques coupled with the use of geometric morphometric techniques. This emerging technology may be utilized to study the effects of beak shape on many critical management issues including heat stress, parasite management, pecking and feeding behaviour. In addition, existing literature identifies several genes related to beak development in chickens and other avian species. Use of morphometric assessments to develop phenotypic data on beak shape and detailed studies on beak-related behaviours in chickens may help in improving management and welfare of commercial poultry.

Middle upper beak fracture in a Red-crowned crane that completely recovered with external skeletal fixation.

An adult Red-crowned crane in captivity that had a displaced compound fracture of the middle upper beak caused by an accident was treated by using Type I-a external skeletal fixator (ESF). The ESF that was equipped with a unilateral epoxy putty fixator and with five half-pins was fixed on the premaxilla bone. The crane with the ESF on the beak was able to feed smoothly by itself. The ESF was removed 49 days after the first surgery. Beak malocclusion, which was observed in the latter half period of fixing, spontaneously improved within one month after removal of the ESF. This is the first successful case of repair of an upper beak fracture in a Red-crowned crane.

Infrared beak treatment method compared with conventional hot-blade trimming in laying hens.

Infrared lasers have been widely used for noninvasive surgical applications in human medicine, and their results are reliable, predictable, and reproducible. Infrared lasers have recently been designed for the express purpose of providing a less painful, more precise beak-trimming method compared with conventional beak trimming. This study was designed to examine the potential of the infrared (IR) beak treatment to provide a welfare-friendly alternative to the conventional hot-blade method for chickens. The birds were beak trimmed by IR at the hatchery or by hot blade at 7 to 10 d of age in a commercial production setting, in accordance with standard procedures. The beak morphology and associated physiological characteristics, including production and aggressive behavior of the birds, were analyzed at 30 wk of age. There was no difference in egg production or bird BW between the 2 beak-trimming treatments. Birds also exhibited no difference in stress physiology measured in the study, such as fluctuating asymmetry and heterophil and lymphocyte profiles. However, birds receiving the IR treatment showed a superior feather condition and reduced aggressiveness under high light intensity, even though they had longer beak stumps. The results may indicate that the IR beak treatment may reduce the damage done by aggressive pecking and feather pecking. Indeed, IR trimming may provide a more welfare-friendly alternative to conventional beak trimming without compromising productivity.

Comparison of beak-trimming methods on early broiler breeder performance.

Beak trimming is necessary in commercial broiler breeders to prevent or decrease trauma as they mature. Two common beak-trimming methods were evaluated by early performance comparison with nontrimmed chicks (NBT). The robotic electrocautery device (ECD) trims and cauterizes the beak tip. The robotic infrared beak-trimming device (IBT) applies an infrared light beam to destroy the live basal tissue while leaving the hard corneum intact for the first approximately 10 d. In 2 experiments, day-of-hatch Ross 708 by-product chicks were obtained from a local hatchery, where 1/3 of the chicks were trimmed using IBT. All chicks were then transported to another hatchery where 1/3 were trimmed using ECD and 1/3 were NBT. Personnel at each hatchery were highly experienced and skilled with their respective technique. All chicks were then transported to University of Arkansas facilities. Before placement in each experiment, chicks were individually neck-tagged and weighed, and in experiment 1, beaks were measured using a digital caliper. A small but significant transient reduction in BW gain was observed at 14 d due to ECD as compared with NBT controls, although ECD was not different than IBT in experiment 1. In experiment 2, IBT birds were significantly heavier at 11 d by 7.8 and 8.7 g than the NBT or ECD, respectively. However, at d 21 and 42, no significant differences in BW or BW gain were observed. When beak trimming was performed on day of hatch by skilled and experienced personnel, little measurable effect on early performance was observed during the first 6 wk of life. Decreased broiler performance is generally considered a sensitive indication of physical or psychogenic stress. Given the marked reduction in beak-inflicted trauma with beak trimming birds as they reach sexual maturity, these results suggest that when properly performed, neither of these beak-trimming methods causes sufficient physical or psychogenic stress to markedly affect early growth rate.

Effects of dietary metabolizable energy levels and beak trimming on the performance, egg quality, and economic viability of layers.

Considering the market availability of new commercial layer strains with distinct characteristics and behaviors, studies to update their nutritional requirements and to evaluate the need to adopt management practices, such as beak trimming, are needed. The objective of the present study was to evaluate the effects of dietary metabolizable energy (ME) levels and beak trimming on the live performance, egg quality, and economics of commercial layers. A total of 640 Novogen White layers were distributed according to a randomized experimental design in a 5 × 2 factorial arrangement (5 ME levels × 2 beak trimming treatments), totaling 10 treatments with 8 replicates of 8 hens each. The evaluated dietary ME levels were 2,600; 2,700; 2,800; 2,900; and 3,000 kcal/kg of feed. Layers were beak-trimmed once (7 days old) or twice (7 and 70 days old). Live performance and egg quality mesuraments and production economics were analyzed. Egg production was positively influenced by dietary ME levels. Feed intake (FI), feed conversion ratio (FCR), egg weight, albumen height, Haugh units, and eggshell strength were positively influenced by increasing dietary ME levels. Hens beak-trimmed once presented higher feed intake and worse FCR than those beak-trimmed twice. Beak trimming did not affect egg production, egg weight, albumen height, Haugh units, and eggshell strength. Production costs increased as dietary ME levels increased. Higher production cost was determined for hens beak-trimmed once than for those beak-trimmed twice. Total revenue was not influenced by the treatments. Gross margin was linearly decreased as dietary ME levels increased and was lower when hens were beak-trimmed once. Increasing dietary ME levels and beak trimming hens once reduce the economic viability of egg production.

Influence of beak trimming and inclusion of sodium butyrate in the diet on growth performance and digestive tract traits of brown-egg pullets differing in initial body weight.

We studied the effects of beak trimming and sodium-butyrate inclusion in the diet on growth performance and gastrointestinal tract (GIT) traits of brown-egg pullets differing in initial BW. In experiment 1, a total of 6 treatments were organized as a 2 × 3 factorial with 2 BW at hatch (light, 33.9 g and heavy, 37.6 g) and 3 beak trimming protocols [mild (MI-0) or aggressive (AG-0) infrared power setting at hatch and traditional hot blade at 8 D of age (HB-8)] as main effects. Initial BW did not affect growth performance or GIT traits at any age. From hatch to 5 wk of age, HB-8 pullets had lower ADFI (P < 0.01) and ADG (P < 0.05) than MI-0 and AG-0 pullets but no differences were detected after this age. Beak trimming did not affect FCR, BW uniformity, GIT traits, or bacteria count in the excreta at any age. In experiment 2, a total of 12 treatments were organized as a 2 × 3 × 2 factorial, with 2 BW at hatch, 3 beak trimming protocol (as per in experiment 1), and 2 levels of a sodium-butyrate additive (0 vs. 0.3%) as main effects. At 7 D of life, beak treatment reduced pullet growth and AG-0 procedure impaired pullet uniformity (P < 0.001) but the birds recovered completely by day 14 (P < 0.001 for the interaction with time). Cumulatively (0 to 6 wk of age), pullets beak treated at hatch (MI-0 and AG-0) had greater ADFI than HB-8 pullets (P < 0.01). Sodium butyrate tended to improve ADG (P = 0.073) and FCR (P = 0.069) with most of the benefits observed for the first 2 wk of life. In summary, initial BW and beak trimming procedure did not affect final pullet growth in any of the 2 experiments, or GIT traits in experiment 1. Sodium butyrate tended to improve growth and FCR from 0 to 6 wk of age but did not affect BW uniformity.

Comparative effects of infrared and one-third hot-blade trimming on beak topography, behavior, and growth.

This research examined the effects of infrared beak treatment on layer chicks. Seventy-two layer chicks were assigned to hot-blade trimming (HB), infrared treatment (IR), or a control treatment. Day-old chicks were pair-housed by treatment. Beak photographs, behavior, and production indices were obtained at intervals for 9 wk posttreatment. All beaks were normally shaped at the onset of the study, and no perceptible treatment-related differences in shape occurred over time (P > 0.05). Posttreatment, HB birds had shorter beaks relative to the other 2 groups (P < 0.05). Control and IR beaks remained comparable in length until tissue eroded in IR beaks at 1 to 2 wk posttreatment. Thereafter, beak length increased in all treatments over time (P < 0.01). Two weeks posttreatment, beaks were longest in control birds, intermediate in HB birds (P < 0.001), and shortest in IR birds (P < 0.001). The HB birds had abnormal deviations from a normal upper-to-lower mandible length ratio than the IR or control birds (P < 0.05). Notable effects of treatment on production emerged by +2 d and persisted for 5 wk. Growth and feed intake were lower in HB and IR birds compared with control birds (P < 0.05), with IR birds performing least well until the fourth week of the study (P < 0.05). Thereafter, they performed similarly to the HB group. Feed waste was lowest in the IR group and was generally greatest in the control group (P < 0.05). There was an overall effect of trimming, irrespective of method, on behavior, particularly eating and drinking behaviors (P < 0.05). Specifically, IR birds were less active (P < 0.01) and spent less time eating (P < 0.01) and drinking (P < 0.05) than did control birds. Behavior in HB birds often ranked intermediate in duration and incidence, but was not significantly different compared with behavior measured in the control and IR groups. Effects of treatment on behavior were not present after 1 wk posttrimming. Results indicate that acute pain occurred with both trimming methods. Although the impact of trimming appeared to be greatest in the IR birds initially, these differences disappeared relatively quickly, and subsequent performance was similar in both trimmed groups.