Soft tissues influence nasal airflow in diapsids: Implications for dinosaurs.

The nasal passage performs multiple functions in amniotes, including olfaction and thermoregulation. These functions would have been present in extinct animals as well. However, fossils preserve only low-resolution versions of the nasal passage due to loss of soft-tissue structures after death. To test the effects of these lower resolution models on interpretations of nasal physiology, we performed a broadly comparative analysis of the nasal passages in extant diapsid representatives, e.g., alligator, turkey, ostrich, iguana, and a monitor lizard. Using computational fluid dynamics, we simulated airflow through 3D reconstructed models of the different nasal passages and compared these soft-tissue-bounded results to similar analyses of the same airways under the lower-resolution limits imposed by fossilization. Airflow patterns in these bony-bounded airways were more homogeneous and slower flowing than those of their soft-tissue counterparts. These data indicate that bony-bounded airway reconstructions of extinct animal nasal passages are far too conservative and place overly restrictive physiological limitations on extinct species. In spite of the diverse array of nasal passage shapes, distinct similarities in airflow were observed, including consistent areas of nasal passage constriction such as the junction of the olfactory region and main airway. These nasal constrictions can reasonably be inferred to have been present in extinct taxa such as dinosaurs.

Effects of functional oils on the growth, carcass and meat characteristics, and intestinal morphology of commercial turkey toms.

Two experiments were conducted to evaluate the effects of functional oils containing cashew nutshell and castor oil on turkey performance and intestinal morphology. In experiment 1, 585 hatchlings were randomly placed in 15 replicate floor pens, (13 poults/pen) with recycled litter and provided feed and water ad libitum. Birds were randomly assigned to 3 dietary treatments from 1 to 12 wk: nonmedicated control, 0.15% functional oils, and 66-ppm monensin. From wk 13 to 20, each initial treatment group was further divided into 3 treatments-control (no additive), 0.15% of functional oils, or 20 ppm of virginiamycin to produce 9 different treatments, 5 replicate pens per treatment. Data on feed weights were collected weekly, and body weight bi-weekly. At termination (20 wk), birds were euthanized, and their meat was processed to determine mass of carcass sections and meat quality, while intestinal samples were collected for histology. In experiment 1, toms fed monensin or functional oils were 10.5 and 4.5% heavier (P < 0.05), respectively, than the controls at 12 wk. Birds fed monensin had a 4% improvement (P < 0.05) in feed conversion as compared to the other treatments. Neither virginiamycin nor the functional oils affected bird performance when fed from 13 to 20 wk. The jejunum villi surface area at 3 wk was most enhanced (P < 0.05) for the poults fed monensin. Supplementation with functional oils significantly reduced leg yield and thiobarbituric-acid reactive substances of white meat after 7 D of storage (P < 0.05). There were no effects on performance or carcass characteristics in experiment 2. While additional confirmatory studies are needed, functional oils in the diet of turkey toms may be a viable alternative to antibiotic growth promotants.

The Nasal Gland in Turkeys (Meleagris gallopavo): Anatomy, Histology, and Ultrastructure.

This study provides a detailed description of the major morphoanatomic and ultrastructural features of the nasal gland in turkeys. In this avian species, nasal or salt glands are bilateral, pale pink, elongated to spindle-shaped, serous, tubuloalveolar structures, with a mean length ranging from 0.64 ± 0.15 cm in poults of 4 days of age to 2.15 ± 0.17 cm at 22 weeks. Instead of having a supraorbital location as commonly seen in waterfowl and other avian species, these glands run underneath the lacrimal, frontal, and nasal bones in turkeys. The reference point for sample collection for histologic examination is just before the rostral edge of the eyelid. Each gland adheres to the surrounding bone through a thick capsule of dense connective tissue merging with the skull periosteum. Histologically, the salt gland consists of secretory tubuloalveolar structures, lined by cuboidal epithelial cells with a central canaliculus and ducts. There are small and large ducts lined by a bilayered epithelium consisting of large apical columnar secretory cells occasionally admixed with rare cuboidal cells. These cells are periodic acid Schiff negative and slightly Alcian blue positive. Both alveolar and secretory ductal cells contain slightly electrondense granular vesicles, highly folded lateral surfaces, and large numbers of mitochondria, characteristic of ion-transporting epithelia. This study provides valuable information for the accurate identification and localization of the nasal gland during necropsy, as well as its correct histologic interpretation, ultimately improving our understanding of the role of this gland in the pathophysiology of specific diseases in turkeys.

La glándula nasal en pavos (Meleagris gallopavo): Anatomía, histología y ultraestructura Este estudio proporciona una descripción detallada de las principales características morfo-anatómicas y ultraestructurales de la glándula nasal en pavos. En esta especie aviar, las glándulas nasales o glándulas salinas son estructuras bilaterales, tubuloalveolares de color rosa pálido, alargadas y serosas, con una longitud media que varía de 0.64 ± 0.15 centímetros en los pavipollos de 4 días de edad hasta 2.15 ± 0.17 centímetros en aves a las 22 semanas. En lugar de tener una ubicación supraorbital como se ve comúnmente en las aves acuáticas y otras especies de aves, estas glándulas corren por debajo de los huesos lagrimales, frontales y nasales en los pavos. El punto de referencia para la recolección de muestras para el examen histológico es justo antes del borde rostral del párpado. Cada glándula se adhiere al hueso circundante a través de una gruesa cápsula de tejido conectivo denso que se fusiona con el periostio del cráneo. Histológicamente, la glándula salina consiste en estructuras tubulo-alveolares secretoras, revestidas por células epiteliales cuboidales con un canalículo central y conductos. Hay conductos pequeños y grandes revestidos por un epitelio de dos capas que consiste en grandes células secretoras columnares apicales ocasionalmente mezcladas con escasas células cuboidales. Estas células son ácido periódico de Schiff negativas y ligeramente positivas para el azul de alcián. Las células ductales alveolares y secretoras contienen vesículas granulares ligeramente electrondensas, superficies laterales altamente plegadas y grandes cantidades de mitocondrias, características de los epitelios transportadores de iones. Este estudio proporciona información valiosa para la identificación y localización exacta de la glándula nasal durante la necropsia, así como su correcta interpretación histológica, mejorando en última instancia nuestra comprensión del papel de esta glándula en la fisiopatología de enfermedades específicas en pavos.

Pinopsin and photoreception in the pineal organ of the domestic turkey during post-hatching development.

The avian pineal organ is photosensitive because of the presence of photopigments, of which pinopsin seems to be one of the most important. This organ is subject to far-reaching changes during post-hatching development, but evidence regarding pinopsin presence and direct photoreception during this time is lacking. This study was carried out to demonstrate the following: 1) the structures showing immunoreactivity to pinopsin in the turkey pineal organ, 2) the changes of these structures during development, 3) the pinopsin localization in pinealocytes in monolayer cultures, and 4) the role of direct photoreception in the regulation of melatonin secretion in pineal organs in adult turkeys. Pinopsin immunoreactivity was localized in the apical extensions of columnar cells limiting the follicular lumen, in fiber-like structures located between columnar cells in the inner part of follicle wall, in string-shapes or small spherical structures distributed in the outer part of follicle wall and in amorphous material inside the follicle lumen. In young birds, immunoreactivity was also sporadically noted in cell bodies of rudimentary receptor pinealocytes. The distribution of pinopsin showed prominent age-dependent changes, including a subsequent increase in pinopsin-positive structures in the outer part of the follicle wall and a prominent reduction in the number and size of positive apical extensions in 40- and 56-week-old turkeys. These data demonstrate that the role of secretory pinealocytes in pineal photoreception increases with age. In monolayer cultures, all pinealocytes showed strong reactions in club- or bulbous-shaped prolongations. The pineal organs of adult birds were less sensitive to light exposition at night than those of young turkeys, which points to differences in light sensitivity between rudimentary receptor and secretory pinealocytes. However, direct photoreception could play an important role in the regulation of melatonin secretion in adult turkeys.

Structural changes in the small intestine of female turkeys receiving a probiotic preparation are dose and region dependent.

Gut microbiota have been shown to play a critical role in the maintenance of host health. Probiotics, which regulate gut microbiota balance, could serve as an effective alternative to antibiotic growth promoters. Since changes in the gastrointestinal tract, caused by a variety of different strains, groups and amounts of microorganisms, may be reflected in its histological structure, the aim of the present study was to examine the effects of rising doses of a mixed probiotic preparation on the structure and development of the small intestine of female turkeys. Eighty, three-day-old, healthy, female turkeys (Big-6 breed) were used in the current (16-week) study. The turkeys were randomly allocated to four weight-matched (59.70 ± 0.83 g) groups (n = 20), according to probiotic treatment dose (0, 107 cfu•g-1, 108 cfu•g-1 or 109 cfu•g-1, in 500 g•1000 kg-1) (cfu - a colony-forming unit). Three, non-genetically modified strains of probiotic cultures obtained from poultry, four bacterial and one yeast culture, were used. Histomorphometric analysis of the structure of the small intestinal wall of the duodenum and jejunum was performed. All probiotic doses used in the current study exerted a beneficial effect on the histological structure of the small intestine; however, the observed effect was dose and region dependent. Significant increases in villi height, crypt depth, villi and crypt width, mucosa thickness, epithelial height, enterocyte number, absorption surface and intestinal ganglia geometric indices were observed, specifically in the duodenum of birds receiving an intermediate dose of probiotic (108 cfu•g-1). The probiotic doses used in the current study differed significantly in their effect on the small intestine (P < 0.01), with the intermediate dose (108 cfu•g-1) significantly improving 58% of the parameters assessed, compared to the control. The duodenum was more susceptible to the favourable effects of the probiotic than the jejunum (56% v. 31% improvement in the parameters assessed) (P < 0.01). The weakest favourable effect was observed in the group that received the highest dose of probiotic.

Developmental morphology of the turkey pineal organ. Immunocytochemical and ultrastructural studies.

Our previous study showed that the turkey pineal organ, in contrast to that of the chicken, is characterized by a follicular structure throughout the entire period of post-hatching life. Despite the preservation of the follicular organization, the histological structure of the pineal follicles in turkeys changes prominently with age. The present research was performed to investigate the cellular composition and organization of the follicle wall as well as the ultrastructure of parenchymal cells in the turkey pineal organ during the period of post-hatching development. Pineal organs were collected from female turkeys at 2 days, 2 weeks, 4 weeks, 10 weeks, 20 weeks, 30 weeks, 40 weeks, and 56 weeks post-hatching. The organs were prepared for immunocytochemical studies using antibodies against N-acetylserotonin O-methyltransferase (ASMT), glial fibrillary acidic protein (GFAP) and proliferating cell nuclear antigen (PCNA) and for ultrastructural examination. The results showed that regardless of age, the pineal follicle was formed by ASMT-immunopositive cells, among which rudimentary photoreceptor and secretory pinealocytes were identified. The second component of the follicle wall consisted of GFAP-immunopositive cells, as represented by ependymal-like and astrocyte-like cells. Rudimentary photoreceptor pinealocytes and ependymal-like cells formed the inner part of the follicle wall, while secretory pinealocytes and astrocyte-like cells created the outer part. Three forms of the pineal follicle structure characteristic of young (two days to ten weeks), young adult (20-30 weeks) and adult (40-56 weeks) turkeys were distinguished. These forms primarily differed in the relative dimensions of the inner and outer parts of the follicle wall. Ultrastructural studies showed prominent changes in the organization of rudimentary receptor pinealocytes during the investigated period of life. These cells developed until the age of 20 weeks, at which time they appeared as strongly elongated cells with a stratified, highly regular distribution of organelles. In adult turkeys, rudimentary receptor pinealocytes showed pronounced regressive changes; however, we never observed their transformation into cells of the secretory type. Secretory pinealocytes increased in number and size during the post-hatching period, which was especially pronounced after 20 weeks of age. The most prominent changes in the supporting cells included the intensification of GFAP-immunoreactivity due to the accumulation of filaments in the cytoplasm and the development of astrocyte-like cells. The increase in the number of secretory pinealocytes and astrocyte-like supporting cells resulted in the formation of two distinct parts of the follicle wall in the pineal organs of young adult and adult turkeys.

Waddle and shuffle: gait alterations associated with domestication in turkeys.

Domestication has altered turkey morphology by artificially selecting for increased muscle mass and breast meat. Artificial selection has resulted in birds that weigh up to 3 times more than their wild counterparts, with relatively little change in the length of their bones and limbs. Considering these structural changes, it seems probable that domestic turkey locomotor kinematics and kinetics would also be altered. To examine the locomotor dynamics of wild and domestic turkeys, we had both strains walk down a runway with a force plate at the center to measure their ground reaction forces and gait parameters. The location of their center of mass was also quantified using a force plate and bi-planar x-ray and found to be further anterior in the domestic strain. The domestic turkeys locomoted across a lower range of speeds (0.25-1.64 ms-1) than the wild turkeys (0.26-3.26 ms-1) and increased their stride frequency at a higher rate. They also displayed large lateral oscillations, i.e. waddling, during walking that translated into relatively high medio-lateral ground reaction forces and lateral kinetic energy (3.5 times higher than that of wild turkeys). The results indicate that domestic turkey locomotion is not simply a slowed down version of wild turkey locomotion. The changes in gait observed are similar to the shuffling gait present in some human populations, such as Parkinson's patients, which serves to increase stability. The domestic turkey's increased body mass and more anterior center of mass position may require these kinematic and kinetic gait differences.

Gross Morphometry, Histomorphometry, and Immunohistochemistry Confirm Early and Persistent Jejunal Crypt Hyperplasia in Poults with Enteritis and Depressed Growth.

Phosphorylated histone 3 (PH3) and cleaved caspase 3 (CCASP3) were used to detect proliferating and apoptotic cells, respectively, in the jejunums of female sibling poults, with and without enteritis and depressed growth, from hatch to day 35. Poults that developed enteritis and depressed growth (SIB flock) were raised on a commercial farm in eastern North Carolina, whereas poults with normal growth and no enteritis (TAU flock) were raised in the Teaching Animal Unit at North Carolina State University College of Veterinary Medicine. Beginning on day 5 through day 35 and at processing, TAU poults were significantly heavier than SIB poults. Jejunal weights, relative jejunal weights, and jejunal densities were greater in SIB poults from day 10 through 35. Jejunal efficiency (body weight /jejunal length) was higher in TAU poults at day 5 and days 10 through 35. Mucosal thickness was greater in SIB poults between days 7 and 21 but greater in TAU poults at days 28 and 35. From day 7 to 35, villus-to-crypt ratios were higher for TAU poults and lower for SIB poults because hyperplastic crypts formed a greater percentage of the mucosa in SIB poults. By day 7, PH3- and CCASP3-positive cells were increased in SIB poults, showing that mucosal changes resulted from combined crypt epithelial hyperplasia and increased apoptosis of villous enterocytes. Findings in this study confirm that enteritis, in the absence of clinical signs, and depressed growth in turkey poults begins by day 7, can be identified microscopically, persists for at least 35 days, is associated with lower processing weights, and has a profound negative effect on turkey growth.

The effect of raw and fermented rapeseed cake on the metabolic parameters, immune status, and intestinal morphology of turkeys.

This study evaluated the effects of including 15% of raw or fermented rapeseed cake (RRC and FRC, respectively) in turkey diets on the growth performance, antioxidant and immune status, and intestinal morphology of birds. Rapeseed cake was fermented using the commercial 6-phytase enzyme preparation, and dried. A total of 1,350 day-old female Hybrid Converter turkeys were randomly allocated to 3 dietary treatments with 9 replicates per treatment and 50 birds per replicate. All diets were isonitrogenous and isocaloric, and contained various protein sources. In the control group (C), soybean meal was the main source of dietary protein, and the remaining groups were fed diets containing 15% of RRC or FRC. Fermentation considerably reduced the concentrations of phytate-phosphorus and glucosinolates in rapeseed cake. In comparison with RRC, turkeys receiving FRC achieved higher average final body weight (BW), comparable with that noted in the control group. Both RRC and FRC stimulated the antioxidant system of turkeys, which was reflected in a decrease in the concentrations of lipid hydroperoxides (LOOH) and malondialdehyde (MDA), and an increase in the total antioxidant potential (FRAP) and the concentration of total glutathione (GSH + GSSG) in blood plasma, compared with the control group. Turkeys fed diets with RRC were characterized by the highest blood vitamin C concentrations, the highest activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and lower catalase (CAT) activity. The dietary inclusion of rapeseed cake contributed to an increase in villus height and mucosal thickness in the duodenum, and a more beneficial influence was exerted by RRC. It can be concluded that the fermentation of rapeseed cake considerably reduces the concentrations of glucosinolates and phytate-phosphorus, and increases the final BW of turkeys. Diets containing 15% of RRC and FRC do not compromise metabolic parameters or immune function, and exert positive effects on antioxidant status and intestinal histomorphology in turkeys.

Differences in aromatase expression and steroid hormone concentrations in the reproductive tissues of male domestic turkeys (Meleagris gallopavo) with white and yellow semen.

1. To show hormonal differences between male turkeys with yellow semen syndrome (YSS) and white, normal semen (WNS), the expression of aromatase, oestrogen receptor α (ERα), and oestrogen receptor ß (ERß) as well as testosterone and oestradiol concentrations in YSS and WNS testes, epididymis, and ductus deferens were examined. 2. To measure gene expression levels of aromatase and oestrogen receptors (ERs), three complementary techniques (real-time PCR, Western blot, and immunohistochemistry) were used, whereas steroid hormone levels were determined radio-immunologically. 3. Upregulation of aromatase and ERα mRNAs in YSS testes (P < 0.05; P < 0.01), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.05; P < 0.01) compared to those of WNS tissues was detected. Significant increases in the levels of aromatase and ERα proteins were detected in YSS testes (P < 0.001; P < 0.05), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.001; P < 0.05). The expression of ERß mRNA and protein level was upregulated in the testes (P < 0.05; P < 0.01) and epididymis (P < 0.001; P < 0.01) but not in ductus deferens where it was downregulated (P < 0.01; P < 0.01). Increased intensity of immunoreactive proteins in YSS versus WNS reproductive tissues corroborated gene expression results. 4. Testosterone concentration diminished in YSS epididymis (P < 0.05) and ductus deferens (P < 0.05), but not in the testes, remaining at high level (P < 0.05) compared to WNS values. Concomitantly, increased oestradiol concentration was found in YSS testes (P < 0.05) and epididymis (P < 0.05) but decreased in the ductus deferens (P < 0.05). 5. From the published literature, this study is the first to demonstrate the ability for androgen aromatisation in the turkey reproductive tissues and to show the cellular targets for locally produced oestrogens. The data suggested that the androgen/oestrogen ratio is a mechanistic basis for amplification of differences between turkeys with white and yellow semen and that these results can have a relevance in applied sciences to widen the knowledge on domestic bird reproduction.

An analysis of beak shape variation in two ages of domestic turkeys (Meleagris gallopavo) using landmark-based geometric morphometrics.

The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak shape variation using geometric morphometrics. Dorsal and right lateral images were taken of 2442 turkeys at 6 and 18.5 weeks of age. Landmarks were digitized in tpsDig in three analyses of the dorsal upper mandible, lateral upper mandible, and lateral lower mandible shape of each turkey at both ages. The coordinate data were then subjected to a principal components analysis (PCA), multivariate regression, and a canonical variates analysis (CVA) with a Procrustes ANOVA in MorphoJ. For the dorsal images, three principal components (PCs) showed beak shape variation ranged from long, narrow, and pointed to short, wide, and blunt upper mandibles at both ages (6 weeks: 95.36%, 18.5 weeks: 92.21%). Three PCs showed the lateral upper mandible shape variation ranged from long, wide beaks with long, curved beak tips to short, narrow beaks with short, pointed beak tips at both ages (6 weeks: 94.91%, 18.5 weeks: 94.33%). Three PCs also explained 97.80% (6 weeks) and 97.11% (18.5 weeks) of the lateral lower mandible shape variation ranging from wide and round to narrow and thin lower mandibles with superior/inferior beak tip shifts. Beak size accounted for varying proportions of the beak shape variation (0.96-54.76%; P < 0.0001) in the three analyses of each age group. For all the analyses, the CVA showed sexual dimorphism in beak shape (P < 0.0001) with female upper mandibles appearing wider and blunter dorsally with long, curved beak tips laterally. Whereas male turkey upper mandibles had a narrow, pointed dorsal appearance and short, pointed beak tips laterally. Future applications of beak shape variability could have a genetic and welfare value by incorporating beak shape variation to select for specific turkey beak phenotypes as an alternative to beak treatment.

Turkey model for flexor tendon research: in vitro comparison of human, canine, turkey, and chicken tendons.

BACKGROUND: Flexor tendon injuries are one of the most common hand injuries and remain clinically challenging for functional restoration. Canine and chicken have been the most commonly used animal models for flexor tendon-related research but possess several disadvantages. The purpose of this study was to explore a potential turkey model for flexor tendon research. METHODS: The third digit from human cadaveric hands, canine forepaws, turkey foot, and chicken foot were used for this study. Six digits in each of four species were studied in detail, comparing anatomy of the flexor apparatus, joint range of motion tendon excursion, tendon cross-sectional area, work of flexion, gliding resistance at the level of the A2 pulley, modulus of elasticity, suture retention strength, and histology across species. RESULTS: Anatomically, the third digit in the four species displayed structural similarities; however, the tendon cross-sectional area of the turkey and human were similar and larger than canine and chicken. Furthermore, the turkey digit resembles the human's finger with the lack of webbing between digits, similar vascularization, tendon excursion, work of flexion, gliding resistance, mechanical properties, and suture holding strength. More importantly, human and turkey tendons were most similar in histological appearance. CONCLUSIONS: Turkey flexor tendons have many properties that are comparable to human flexor tendons which would provide a clinically relevant, economical, nonhuman companion large animal model for flexor tendon research.

Comparative Quantitative Studies on the Microvasculature of the Heart of a Highly Selected Meat-Type and a Wild-Type Turkey Line.

In this study the macroscopic and microscopic structure of the heart of a fast growing, meat-type turkey line (British United turkeys BUT Big 6) and a wild-type turkey line (Canadian Wild turkey) were compared. At 8 and 16 weeks of age, 10 birds of each genotype and sex were sampled. The body mass and heart mass of the meat-type turkey both increased at a faster rate than those of the wild-type turkey. However in both turkey lines, the relative heart mass decreased slightly with age, the decrease was statistically significant only in the male turkeys. Furthermore meat-type turkeys had a significantly (p < 0.01) lower relative heart mass and relative thickness of the left ventricle compared to the wild-type turkeys of the same age. The wild-type turkeys showed no significant change in the size of cardiomyocytes (cross sectional area and diameter) from 8 weeks to 16 weeks. In contrast, the size of cardiomyocytes increased significantly (p < 0.001) with age in the meat-type turkeys. The number of capillaries in the left ventricular wall increased significantly (p < 0.001) in wild-type turkeys from 2351 per mm2 at the age of 8 weeks to 2843 per mm2 at 16 weeks. However, in the meat-type turkeys there were no significant changes, capillary numbers being 2989 per mm2 at age 8 weeks and 2915 per mm2 at age 16 weeks. Correspondingly the area occupied by capillaries in the myocardium increased in wild-type turkeys from 8.59% at the age of 8 weeks to 9.15% at 16 weeks, whereas in meat-type turkeys this area decreased from 10.4% at 8 weeks to 9.95% at 16 weeks. Our results indicate a mismatch in development between body mass and heart mass and a compromised cardiac capillary density and architecture in the meat-type turkeys in comparison to the wild-type turkeys.

Nasal conchae function as aerodynamic baffles: Experimental computational fluid dynamic analysis in a turkey nose (Aves: Galliformes).

We tested the aerodynamic function of nasal conchae in birds using CT data from an adult male wild turkey (Meleagris gallopavo) to construct 3D models of its nasal passage. A series of digital "turbinectomies" were performed on these models and computational fluid dynamic analyses were performed to simulate resting inspiration. Models with turbinates removed were compared to the original, unmodified control airway. Results revealed that the four conchae found in turkeys, along with the crista nasalis, alter the flow of inspired air in ways that can be considered baffle-like. However, these baffle-like functions were remarkably limited in their areal extent, indicating that avian conchae are more functionally independent than originally hypothesized. Our analysis revealed that the conchae of birds are efficient baffles that-along with potential heat and moisture transfer-serve to efficiently move air to specific regions of the nasal passage. This alternate function of conchae has implications for their evolution in birds and other amniotes.

Structure and age-dependent development of the turkey liver: a comparative study of a highly selected meat-type and a wild-type turkey line.

In this study the macroscopic and microscopic structure of the liver of a fast growing, meat-type turkey line (British United turkeys BUT Big 6, n=25) and a wild-type turkey line (Wild Canadian turkey, n=48) were compared at the age of 4, 8, 12, 16, and 20 wk. Because the growth plates of long bones were still detectable in the 20-week-old wild-type turkeys, indicating immaturity, a group of 8 wild-type turkeys at the age of 24 wk was included in the original scope of the study. Over the term of the study, the body and liver weights of birds from the meat-type turkey line increased at a faster rate than those of the wild-type turkey line. However, the relative liver weight of the meat-type turkeys declined (from 2.7 to 0.9%) to a greater extent than that of the wild-type turkeys (from 2.8 to 1.9%), suggesting a mismatch in development between muscle weights and liver weights of the meat-type turkeys. Signs of high levels of fat storage in the liver were detected in both lines but were greater in the wild-type turkey line, suggesting a better feed conversion by the extreme-genotype birds i.e., meat-type birds. For the first time, this study presents morphologic data on the structure and arrangement of the lymphatic tissue within the healthy turkey liver, describing two different types of lymphatic aggregations within the liver parenchyma, i.e., aggregations with and without fibrous capsules. Despite differences during development, both adult meat-type and adult wild-type turkeys had similar numbers of lymphatic aggregations.

Is the Collagen Primed for Mineralization in Specific Regions of the Turkey Tendon? An Investigation of the Protein-Mineral Interface Using Raman Spectroscopy.

The tendons in the turkey leg have specific well-defined areas which become mineralized as the animal ages and they are a thoroughly characterized model system for studying the mineralization process of bone. In this study, nondestructive Raman spectroscopic analysis was used to explore the hypothesis that regions of the turkey tendon that are associated with mineralization exhibit distinct and observable chemical modifications of the collagen prior to the onset of mineralization. The Raman spectroscopy features associated with mineralization were identified by probing (on the micrometer scale) the transition zone between mineralized and nonmineralized regions of turkey leg tendons. These features were then measured in whole tendons and identified in regions of tendon which are destined to become rapidly mineralized around 14 weeks of age. The data show there is a site-specific difference in collagen prior to the deposition of mineral, specifically the amide III band at 1270 cm(-1) increases as the collagen becomes more ordered (increased amide III:amide I ratio) in regions that become mineralized compared to collagen destined to remain nonmineralized. If this mechanism were present in materials of different mineral fraction (and thus material properties), it could provide a target for controlling mineralization in metabolic bone disease.

The effect of toe trimming on behavior, mobility, toe length and other indicators of welfare in tom turkeys.

Society is increasingly concerned about the welfare of animals kept for food production, for this reason, invasive procedures such as toe trimming in turkeys must be studied to assess the corresponding welfare implications and to ensure such procedures are acceptable for continued use. To this end, research was conducted to evaluate the welfare effects of toe trimming on toms raised to 140 d. The study used 306 Hybrid Converter toms, half of which were toe trimmed using a Microwave Claw Processor (MCP) which group are denoted T, and half of which were sham treated but not trimmed, which group are denoted NT. Turkey behavior was observed on d 1, 3, 5, and 133. Toe cross sections were taken every second day for 14 d after treatment and were used to histologically examine the healing process. Toe length, gait score, and bird stance were assessed on d 55, 84, 119, and 139. For the first 5 d after treatment, T birds demonstrated less active behaviors such as feeding, standing, walking and running (P ≤ 0.05), indicative of pain with the effect diminishing with age. At d 133, T turkeys stood more and walked less than NT birds (P ≤ 0.05). Gait score and bird stance were not affected by treatment. Trimmed toes were on average 91.9% of the length of NT toes and toe length was more variable (P ≤ 0.05) as a result of the trimming process. Histological examination indicated T toes had complete epithelium closure over the healthy tissue by d 8 and were fully healed by d 14. Although bird mobility and stance were unaffected by treatment, turkey behavior both early and late in the production cycle were suggestive of pain and balance effects; both indicators of reduced welfare as a result of toe trimming.

Ontogeny of an iridescent nanostructure composed of hollow melanosomes.

Iridescent colors in feathers are some of the brightest in nature, and are produced by coherent light scattering from periodic arrangements of melanosomes (melanin-containing organelles). Hollow melanosomes, an evolutionary innovation largely restricted to birds, contain an optically powerful combination of high and low refractive indices (from the melanin and air, respectively) that enables production of brighter and more saturated colors than solid melanosomes. However, despite their significance to avian color and potential utility as optical biomaterials, little is known about the ontogeny of either the melanosomes themselves or the nanostructures they comprise. We used light and electron microscopy to characterize nanostructural development in regenerating feathers of wild turkeys, a species with iridescent color produced by a hexagonally close-packed array of hollow melanosomes. We found that melanosomes form as solid bodies in melanocytes. Later in development, largely after placement in developing barbules, their interiors dissolve and leave hollow cores. These now hollow melanosomes are initially disorganized in the barbule, but become close-packed as they are pulled to the edge of the barbule, likely through a combination of forces including depletion-attraction. These data suggest that these structurally colored tissues are self-assembled and represent novel pathways of development.

Systematization, distribution and territory of the caudal cerebral artery on the brain's surface of the turkey (Meleagris gallopavo) / Sistematização, distribuição e território da artéria cerebral caudal na superfície do encéfalo em peru (Meleagris gallopavo)

Thirty Meleagris gallopavo heads with their neck segments were used. Animals were contained and euthanized with the association of mebezonium iodide, embutramide and tetracaine hydrochloride (T 61, Intervet ) by intravenous injection. The arterial system was rinsed with cold saline solution (15°C), with 5000IU heparin and filled with red-colored latex. The samples were fixed in 20% formaldehyde for seven days. The brains were removed with a segment of cervical spinal cord and after, the dura-mater was removed and the arteries dissected. The cerebral carotid arteries, after the intercarotid anastomosis, were projected around the hypophysis, until they reached the tuber cinereum and divided into their terminal branches, the caudal branch and the rostral branch. The rostral branch was projected rostrolateralwards and gave off, in sequence, two collateral branches, the caudal cerebral and the middle cerebral arteries and the terminal branch was as cerebroethmoidal artery. The caudal cerebral artery of one antimere formed the interhemispheric artery, which gave off dorsal hemispheric branches to the convex surface of both antimeres. Its dorsal tectal mesencephalic branch, of only one antimere, originated the dorsal cerebellar artery. In the interior of the cerebral transverse fissure, after the origin of the dorsal tectal mesencephalic artery, the caudal cerebral artery emitted occipital hemispheric branches, pineal branches and medial hemispheric branches, on both antimeres. The caudal cerebral artery's territory comprehended the entire surface of the dorsal hemioptic lobe, the rostral surface of the cerebellum, the diencephalic structures, the caudal pole and the medial surface of the cerebral hemisphere and in the convex surface, the sagittal eminence except for its most rostral third. Due to the asymmetry found in the caudal cerebral arteries' ramifications, the models were classified into three types and their respective subtypes.

Foram utilizadas 30 cabeças com o segmento de pescoço deMeleagris gallopavo. Os animais foram contidos e eutanasiados com a associação de iodeto de mebezônio, embutramida e cloridrato de tetracaína (T 61 Intervet ), via endovenosa. O sistema arterial foi lavado com solução salina resfriada (15°C), com 5000UI heparina e preenchido com látex corado em vermelho. As peças foram fixadas em formaldeído a 20% por sete dias. O encéfalo foi removido com um segmento de medula espinhal, a dura-máter removida e as artérias dissecadas. As artérias carótidas do cérebro, após a anastomose intercarótica, projetaram-se contornando a hipófise até alcançarem o túber cinéreo e dividiram-se em seus ramos terminais, o ramo caudal e o ramo rostral. O ramo rostral projetou-se rostro-lateralmente emitindo em sequência seus dois principais ramos colaterais, as artérias cerebral caudal e cerebral média terminado-se como artéria cerebroetmoidal. A artéria cerebral caudal de um antímero formava a artéria inter-hemisférica que lançava ramos hemisféricos dosais para a face convexa de ambos os antímeros. Seu ramo tectal mesencefálico dorsal de apenas um antímero originava a artéria cerebelar dorsal. No interior da fissura transversa do cérebro após a origem da artéria tectal mesencefálica dorsal artéria cerebral caudal lançou ramos hemisféricos occipitais, ramos pineais e hemisféricos mediais em ambos os antímeros. O território da artéria cerebral caudal compreendeu toda a superfície do hemi lobo óptico dorsal, a face rostral do cerebelo, as estruturas diencefálicas, o polo caudal e a face medial do hemisfério cerebral e na face convexa do hemisfério cerebral a eminência sagital exceto seu terço mais rostral. Devido à assimetria encontrada nas ramificações das artérias cerebrais caudais, foram classificados os modelos em três tipos com seus respectivos subtipos.