Bruno Moraes Assis

Microstructure of Holstein and Gir breed adult bovine hooves: histomorphometry, three-dimensional microtomography and microhardness test evaluation

This study aimed to characterize and compare the aspects involved in the microstructural formation of the Holstein and Gir breed hoof wall by histomorphometry, three-dimensional microtomography and microhardness test techniques. Seventy-two (18H/18G thoracic and 18H/18G pelvic) Holstein (H) and Gir (G) breed hooves were collected in slaughterhouses. The hooves were divided into six groups according to breed and age group: 24 to 36 months (C1H/C1G), 36 to 60 months (C2H/C2G) and over 60 months (C3H/C3G). The normality and homogeneity analysis of morphometric variables by the Kolmogrov-Sminov and Bartlett tests was conducted as a statistical model. Once the assumptions were met, the Sigmastat 3.5 software was used and the means were compared by T test. The 5% probability level is considered. When the assumptions were not met, the means were compared by the Mann-Whitney nonparametric test, considering the 5% probability level. When comparing the Holstein and Gir breeds, no differences were noticed between them as to the length of the dermal papillae; young animals showed thicker papillae than adult animals; the Holstein breed hooves showed higher amount of 7pores on the wall and on the sole compared to the Gir breed; Holstein cattle hooves showed greater microhardness than Gir cattle; there was no microhardness difference between pigmented and non-pigmented hooves of Holstein and Gir cattle.

In vivo biocompatibility of nanostructured Chitosan/Peo membranes

Electrospinning is a technique that allows the preparation of nanofibers from various materials. Chitosan is a natural and abundant easily obtained polymer, which, in addition to those features, proved to be biocompatible. This work used nanostructured chitosan and polyoxyethylene membranes as subcutaneous implants in Wistar rats to evaluate the biocompatibility of the material. Samples of the material and tissues adjacent to the implant were collected 7, 15, 30, 45 and 60 days post-implantation. Macroscopic integration of the material to the tissues was observed in the samples and slides for histopathological examination that were prepared. It was noticed that the material does not stimulate the formation of adherences to the surrounding tissues and that there is initial predominance of neutrophilia and lymphocytosis, with a declining trend according to the increase of time, featuring a non-persistent acute inflammatory process. However, the material showed fast degradation, impairing the macroscopic observation after fifteen days of implantation. It was concluded that the material is biocompatible and that new studies should be conducted, modifying the time of degradation by changes in obtaining methods and verifying the biocompatibility in specific tissues for biomedical applications.

Biochemical composition of the hoof capsule of buffaloes and its influence on hoof quality

O presente estudo objetivou estabelecer os parâmetros bioquimicos da muralha abaxial, muralha dorsal e sola do casco dos digitos toracico medial e pelvico lateral dos bubalinos. Foram realizadas analises bioquimicas destrutivas das amostras dos cascos para se obterem os teores de materia seca (MS), materia mineral (MM), materia orgânica (MO), proteina bruta (PB) e extrato etereo (EE). As analises bioquimicas nao destrutivas foram empregadas para se avaliarem os niveis de enxofre (S), calcio (Ca), potassio (K), fosforo (P), zinco (Zn) e cobre (Cu). Concluiu-se que os parâmetros materia seca, materia mineral, materia orgânica, proteina bruta e extrato etereo do estojo corneo dos digitos de bubalinos podem ser definidos por analises bioquimicas destrutivas e nao destrutivas. Os maiores valores dos elementos minerais estao concentrados nos digitos que suportam o maior peso do animal, sugerindo que existe uma relacao positiva entre esses parâmetros. Alem disso, este estudo revelou que as maiores concentracoes de MS, PB e minerais como, K, Zn e Cu estao nos digitos que carregam o maior peso de massa corporal, o que indica que ha uma correlacao positiva entre os parâmetros acima referidos, resistencia e crescimento do estojo corneo dos digitos. Em relacao ao elemento de S, este estudo demonstrou que a sua maior concentracao situa-se nos digitos laterais dos membros pelvicos.

Microtomographic Parameters and Nanoindentation of the Hoof of Girolando Cattle

The aim of this study was to describe the microstructure of the pigmented and depigmented hoof capsule of Girolando cattle by bi‐ and tridimensional microtomography and nanoindentation, analysing the possible relation between these findings and the susceptibility of such animals to podal diseases. To carry out the microtomography and the nanoindentation, duplicated samples were collected from the dorsal wall, abaxial wall and pre‐bulbar sole of the hoof capsule. Material collection was performed in 40 medial digits of thoracic limbs and 40 lateral digits of pelvic limbs. The bidimensional microtomography showed that the dorsal wall of the thoracic and pelvic limbs presented higher density, followed by the abaxial wall, and finally by the sole, with the lowest density. Moreover, the hoof capsule of cows of Girolando breed is a compact, non‐porous material, and constituted by extratubular and intratubular keratin. By the tridimensional microtomography, it was possible to measure the angles of the corneal tubules in relation to the periople and the claws in the different regions of the hoof capsule, which were 90° for the dorsal wall, 55° for the abaxial wall and 70° for the sole. The tridimensional microtomography also showed corneal tubules of different diameters: 17, 51, 85, 119 and 153 μm. The nanoindentation test, when performed in different regions of the hoof capsule, did not reveal significant difference of Vickers hardness in the evaluated areas. However, we verified a larger elastic module of these regions on the transversal cut of the corneal tubules compared to the longitudinal cut.

Microstructure and Hardness of Buffalo's Hoofs

The aim of this study was to describe the microstructure of hoof capsules of the buffalo. In addition, the study emphasized the morphometric aspects of the horn tubules, the Vickers nanohardness of the dorsal and abaxial walls and sole of the digits of the thoracic and pelvic limbs of the buffalo. The abaxial wall in the thoracic and pelvic digits showed larger diameter of the horn tubules when compared to all dorsal wall and sole. In addition, the abaxial wall of the thoracic digits showed larger diameter of the horn tubules when compared with the pelvic digits. According to the three‐dimensional microtomography, the dorsal wall was higher in density compared with the abaxial wall. The latter exhibited an intermediate density, while the sole showed the lowest density. The Vickers nanohardness test showed that there was no difference in hardness and resistance between the experienced regions. However, the elastic modulus was greater on the transversal section of the hoof capsule. In conclusion, the results of the current study show that modern technologies such as microtomography and subsequent imaging can be used to investigate details of the basic morphology in different regions of the buffalos hoof.

Barbatiman and chitosan creams as adjuvants in rabbit skin wound healing

In this study, 5% barbatiman and 5% chitosan creams were evaluated as adjuvants in the tissue repair process by secondary intention of rabbit’s skin wounds. Four equidistant wounds were induced in the dorsal skin of 20 adult male rabbits, which were submitted to healing by secondary intention and treated with 5% chitosan cream (QC, n=5), 5% barbatiman cream (BC, n=5), 2% allantoin cream (n=5), and base cream (n=5). The creams were applied with the aid of disposable spatulas after washing the wounds. The wounds were daily analyzed by clinical examination for 21 days and histological analyses were performed on the 3rd, 14th, and 21st day after induction. The microscopic evaluation of the wounds of all groups showed macroscopic features of the healing process at different time intervals. The QC and BC treatments helped in the skin repair process in rabbits when compared to the other two treatments. They induced fibroblast activation and early collagen deposition, and modulated re-epithelialization and neovascularization. Thus, it was concluded that BC and QC are efficient and economically feasible as adjuvants in the healing process of skin wounds in rabbits.

Development and evaluation of accessories to improve the posture of veterinary surgeons in surgical procedures conducted in the field

The study was conducted based on the information collected on rural properties in the state of Goias, during practical classes of Surgical Clinic in Large Animals at the Veterinary Hospital of the Escola de Veterinaria e Zootecnia of the Universidade Federal de Goias and during the implementation of outreach projects developed by the institution. An acropostite-phimosis surgical procedure in the bulls in the field was selected, lasting over 30 minutes and requiring movements, posture and strength on the part of the surgeon. Devices were proposed and developed to provide improved comfort and safety to surgeons. The first device was a stool to be used by the professional during the execution of the surgical intervention. The use enabled the surgeon to sit down and rest their feet on the ground, reducing knee bending and distributing the support forces in various muscle groups. For the movement restriction of the surgeon, another accessory was developed to support the foreskin of the animal. Made of wood, this other device serves as a support for keeping the foreskin away from the ground and close to the surgeon. Its length, width and thickness established a good relation with the stool height, providing minimal discomfort to the professional. The third device was designed to assist in the immobilization of the animal and increase safety for the patient and surgical team. A fourth accessory was designed to protect the scapular region and avoid the occurrence of injuries in the radial nerve, myopathies and traumas during the rollover or prolonged stay of the animal in lateral decubitus. The choice of the shape, dimensions and softness of the device was mainly based on the weight of the animal. Such devices have proven to be effective, reducing the time of surgery, making cervical and lumbar movement easier, in addition to providing better support to the surgeon, reducing risks of musculoskeletal diseases.